If consciousness be a mere epiphenomenon… accompanying, but in no way guiding, certain molecular changes in the brain, we shall of course expect… that consciousness is exclusively linked with the functional disintegration of central nervous elements, and varies in its intensity with the rapidity or energy of that disintegration. And ordinary experience, at least within physiological limits, will support some view like this. Yet now and then we find a case where vivid consciousness has existed during a state of apparent coma… tranquilly and intelligently co-existing with an almost complete abeyance of ordinary vital function…. Until this new field has been more fully worked—until the traces of memory which may survive from comatose, ecstatic, syncopal conditions have been revived (by hypnotic suggestion or otherwise), and carefully compared, we have no right to make any absolute assertion as to the concomitant cerebral processes on which consciousness depends. (Myers, 1891c, pp. 116–117)
The hypothesis that consciousness is the product of brain processes, or that mind is merely the subjective concomitant of neurological events, has been and remains the almost universal assumption in neuroscience and psychology. Investigations of certain extraordinary circumstances, however, reveal phenomena that call into question this assumption. An analogy can be drawn with Newtonian dynamics, which appears to explain the physics of everyday life. It was only the investigation of extraordinary circumstances, involving extremely small or large distances, speeds, or mass, that revealed the limits of the Newtonian model and the need for additional explanatory models. So too with the question of the mind-brain relationship: As Myers understood in urging his colleagues in psychology to study subliminal and other unusual psychological phenomena, exploration of extraordinary circumstances may reveal limitations of the current model of mind-brain identity and the need for a more comprehensive explanatory model.
One such extraordinary circumstance is the continued functioning of the mind when the brain appears to be inactive or impaired, such as may occur near death. Myers specifically recognized the importance of such circumstances: “It is possible that we might learn much were we to question dying persons, on their awakening from some comatose condition, as to their memory of any dream or vision during that state” (HP, vol. 2, p. 315), and he thus urged “much more of experiment and observation of mental conditions under anaæthetics, during recovery from fainting, and even during apparent coma” (Myers, 1891c, p. 115). He himself reported three cases of experiences occurring when a person was close to death but then revived (Myers, 1891c, 1886b, p. 305; 1892a, pp. 180–200; HP, vol. 2, pp. 315–323). The importance of such cases lies in the fact that “the patient, while in a comatose state, almost pulseless, and at a temperature much below normal, did, nevertheless, undergo a remarkably vivid series of mental impressions” (1892a, p. 194).
Such experiences have, in recent years, been labeled “near-death experiences,” or NDEs. They are not, however, the isolated and homogeneous phenomenon that such a label suggests. Many experiences called “near-death” experiences have occurred when the person was not physiologically near death, and individual features associated with NDEs occur in a wide variety of conditions in which the person is also clearly not near death. We believe that the difficulties in explaining, and even in defining, the NDE stem at least in part from the failure to examine this phenomenon within the context of this larger family of related experiences. In this chapter, after outlining the general nature of the phenomena known as “NDEs” and the various explanatory models that have been proposed for them, we will then examine some of the other types of experiences that are phenomenologically related to NDEs. These include experiences in which the ordinary perceived relationship between consciousness and the body has been altered—especially “out-of-body experiences,” in which a person’s consciousness seems to be functioning normally, but from a spatial location outside the body. We will also discuss a variety of hallucinatory1 experiences in which a person has seen, heard, or otherwise sensed the presence of a dying or deceased person not physically present. Finally, we will briefly discuss religious “conversion experiences” of the sort described by James (1902/1958). These provide a bridge between NDE-type phenomena and the more extreme manifestations of noetic or life-transforming experiences associated with mysticism, to which we will devote Chapter 8.
We wish to emphasize again that all these phenomena are interrelated in some fundamental but so far poorly understood way. All involve a marked alteration in the ordinary relationship of a person’s consciousness with the external world. We believe it is essential to consider the entire spectrum of experiences when proposing explanations for any one of them. We have chosen to organize this chapter specifically around the experiences known as NDEs, however, because of their extreme theoretical importance. Despite the wide variety of physiological and psychological conditions under which NDEs occur, many such experiences do clearly occur when the brain is severely impaired. At the end of this chapter we will focus specifically on this aspect of NDEs, underscoring the important theoretical implications of experiences of this type for current neurophysiological models of consciousness.
There is no universally agreed on definition of NDEs (Greyson, 1999), but they are generally understood to be the unusual, often vivid and realistic, and sometimes profoundly life-changing experiences occurring to people who have been either physiologically close to death, as in cardiac arrest or other life-threatening conditions, or psychologically close to death, as in accidents or illnesses in which they feared they would die.
The following experiences come from our collection at the University of Virginia and illustrate some of the features commonly reported. The first was reported by a woman who was in surgery after hemorrhaging severely and going into shock:
I had floated out of my body and was looking down on all of this [the doctors and nurses working on her]. I was wearing white. I started floating down a tunnel which had rough looking sides and a blinding, bright light at the end, and I was headed for the lighted end. As I was going through the tunnel I saw my Grandfather’s face, and he was smiling at me. He said something like, “It’s been a long time. Welcome.” He died in 1948, and I was his favorite grandchild; we were very close. I saw several faces on the wall; some of them I knew and some I did not, but they were all smiling. I was almost to the end, and my Great-Grandmother, who helped raise me and I was very close to, appeared, and she said “Go back; you have a child who needs you. You can come here with us later.” I tried to argue with her, but she told me flatly, “You go back.”
Another woman, who was in surgery after suffering massive pulmonary emboli, reported:
Some time after entering the operating room, I found myself above the scene looking down on myself, and the doctors and nurses around me. I could, of course, hear everything they were saying, and I wanted to tell them not to feel so bad, that I couldn’t stand the pain any more and I liked it where I was. I was somewhere where it was so beautiful and peaceful that I wanted to stay there forever. I did not actually see anyone I knew, or anything in particular. There was a bright, but soft light, and I felt the most comforting sense of peace. Suddenly I thought “Ben [her husband] can’t possibly bring up Molly alone; I had better go back,” and that is the last thing I remember. I am absolutely positive that I decided to come back. Since that time I have no fear of dying.
I spent ten days in intensive care, and almost a month in the hospital, but I was never able to mention this to the doctors or nurses. I have mentioned it to only a very few people in the last couple of years, and then reluctantly. I feel as though people might think I am making up a story for attention, but I assure [you] that is not so.
An experience such as this does change your outlook on life and also some of your religious beliefs. I have always been an active church-goer, but only on the surface, I am afraid. Since then, I have given thought to some of the facts I was taught, and have my own way of dealing with them. I wish that people who have a loved one die suddenly, perhaps in an early stage of life, could be made to understand what this felt like, they wouldn’t feel so bad.
Profound experiences near death have been reported throughout history and in many cultures.2 Among the earliest reports is Plato’s description in Book 10 of the Republic of the experiences of the soldier Er during the time when he had been thought dead and placed on a funeral pyre. In more recent times, numerous experiences were reported in the medical literature of the 19th and 20th centuries (for a list of some of these, see Greyson, 1998). The 19th-century physician Brierre de Boismont (1859) described two such experiences. In one of them, a woman who had been delirious and seemed to have died suddenly sighed and was revived by her attendants: “Instead, however, of thanking the persons who had taken such pains to restore her to life, she complained to them of their having recalled her soul from a condition of indescribable repose and happiness…. She added that she had heard [while seemingly dead] the sighs and lamentations of her father, and all that had been said with regard to her funeral” (p. 263).
As we mentioned earlier, later in the 19th century Myers (1892a) reported three cases that included many of the features reported in today’s experiences. In one of these, which occurred in 1889, the patient (a physician himself) seemed to have died from typhoid fever; his physician testified that “he was actually dead as fully as I ever supposed anyone dead,” with no perceptible pulse, heartbeat, or respiration (p. 193). Nonetheless, the patient had a vivid and complex experience of seeming to leave his body and see it, as well as the actions of the people in the room. He then went to a place of great beauty where he felt a presence and saw the face of an unidentified person who radiated great love. He also saw a dark cloud and dark pathway (perhaps corresponding to the later descriptions by other people of a tunnel). He seemed to be given the choice of staying or returning, but when he chose to stay and tried to cross an apparent boundary, he was stopped from proceeding and then suddenly found himself back in his body. Throughout the experience, he seemed to be in a nonphysical body that had “perfect health and strength,” and he reported that “memory, judgment, and imagination, the three great faculties of mind, were intact and active” (pp. 183–184).
The first systematic study was that of Heim (1892/1972), who published a report on his collection of 30 firsthand accounts (including his own) of experiences of mountain climbers who had fallen in the Alps, soldiers wounded in war, workers who had fallen from scaffolds, and individuals who had nearly died in accidents and near-drownings. This study was important for bringing together for the first time a large number of these experiences, including experiences that occur, not when the person is physiologically near death, but when he or she only thinks that death is imminent.
Similar systematic studies were conducted during the early 1970s, particularly by psychiatrist Russell Noyes (e.g., Noyes, 1972, 1976). In 1975 a popular book by the psychiatrist and philosopher Raymond Moody brought widespread attention to such phenomena, and in the past three decades there has been a surge of interest in and study of them.
As research on these experiences has increased, it has become clear that NDEs are not infrequent. Our collection at the University of Virginia now numbers 861 reports, and other researchers, including the many local and national branches of the International Association for Near-Death Studies, have also collected large numbers of cases. Early estimates of the incidence of NDEs may have been inflated by ambiguous criteria for NDEs and by biased sampling (Greyson, 1998), but studies in the past decade, using more explicit criteria and better sampling techniques suggest that NDE-like experiences may occur in about 10–20% of patients close to death (Greyson, 2003; Milne, 1995; Parnia, Waller, Yeates, & Fenwick, 2001; Schwaninger, Eisenberg, Schechtman, & Weiss, 2002; van Lommel, van Wees, Meyers, & Elfferich, 2001).
Although the widespread impression is that NDEs occur among patients who have been clinically dead and then resuscitated, they in fact occur in a wide variety of medical circumstances. An examination of medical records in cases in our collection (all of them experiences reported to us retrospectively) showed that slightly more than half of the patients, although ill enough to have been hospitalized, were at no time in danger of dying (Owens, Cook [Kelly], & Stevenson, 1990; Stevenson, Cook [Kelly], & McClean-Rice, 1989–1990); NDEs may therefore occur when patients fear they are dying even if in fact they are not. Moreover, NDEs can also occur when patients are suddenly confronted with death but escape unharmed, as in falls or near-accidents (e.g., Heim, 1892/1972).3
Nonetheless, there remain a substantial number of cases in which patients were clinically near death, such as during cardiac arrest or some other, usually sudden, loss of vital functions (Finkelmeier, Kenwood, & Summers, 1984; Greyson, 2003; Owens et al., 1990; Parnia et al., 2001; Sabom, 1982; Schoenbeck & Hocutt, 1991; Schwaninger et al., 2002; van Lommel et al., 2001). These include some in children who suffered cardiac arrest (Gabbard & Twemlow, 1984, pp. 154–156; M. Morse, 1983, 1994a, pp. 67–69, 1994b; Serdahely, 1990). In one recent prospective study of 344 cardiac arrest patients, 62 reported NDEs following resuscitation from cardiac arrest (van Lommel et al., 2001). In our own collection of retrospectively reported NDEs, out of 114 cases for which we have obtained and rated medical records, 35 were rated “4” on a 4-point scale of severity of condition, meaning that there was some documentation of loss of vital signs, often including cardiac arrest.
Just as NDEs can occur in a wide variety of circumstances, so do they include a wide variety of features. Frequently recurring features include feelings of peace and joy; a sense of being out of one’s body and watching events going on around one’s body and, occasionally, at some distant physical location; a cessation of pain; seeing a dark tunnel or void; seeing an unusually bright light, sometimes experienced as a “Being of Light” that radiates love and may speak or otherwise communicate with the person; encountering other beings, often deceased persons whom the experiencer recognizes; experiencing a revival of memories or even a full life review, sometimes accompanied by feelings of judgment; seeing some “other realm,” often of great beauty; sensing a barrier or border beyond which the person cannot go; and returning to the body, often reluctantly.
Although all of these features recur frequently in large groups of cases, individual experiences are unique. The number of features reported in individual cases varies, no experience containing all features has been reported, no single feature is common to all NDEs, and features do not necessarily unfold in a particular fixed order. Moreover, in contrast to most NDEs, which are positive experiences, there are also NDEs that are frightening or unpleasant (Greyson & Bush, 1992).4
Some investigators have attempted to evaluate NDEs by quantifying their common features. The most widely used systems have been the Weighted Core Experience Index (WCEI) (Ring, 1980) and the NDE Scale (Greyson, 1983b, 1985), a 32-point rating scale that has been used primarily to determine the “richness” of, or number of features in, individual cases and has shown high internal consistency and reliability, and high correlation with Ring’s WCEI (r = .90).
All the major features of NDEs have been reported in a wide variety of circumstances, but certain features correlate somewhat with the circumstances in which the experiences occur. For example, alterations in the sense of time, unusually rapid thinking, and a revival of memories are more common in near-death events that are sudden and unexpected than in those that may have been anticipated (Greyson, 1985). In a study in which medical records were examined to determine how close to death the person actually was, certain other features, such as an encounter with a brilliant light, enhanced cognitive function, and positive emotions, were more common among individuals who were actually close to death than in those who were not so seriously ill (Owens et al., 1990). People actually close to death were also more likely to report encounters with deceased persons than those who were not (E. W. Kelly, 2001). Although children’s NDEs are generally similar to those of adults, none have been reported that include a life review, perhaps not surprisingly (Bush, 1983; M. Morse, Castillo, Venecia, Milstein, & Tyler, 1986).
One particularly noteworthy feature is that for many experiencers an NDE permanently and dramatically alters the person’s attitudes, beliefs, and values, often leading to beneficial personal transformations. Aftereffects most often reported include increases in spirituality, concern for others, and appreciation of life; a heightened sense of purpose; and decreases in fear of death, in materialistic attitudes, and in competitiveness.5 A large study of NDEs among survivors of cardiac arrest showed that, after both a two-year and an eight-year followup interval, people who had NDEs in connection with the cardiac arrest had a significant decrease in their fear of death and a significant increase in their belief in survival after death, whereas those who had not had an NDE tended not to believe in survival (van Lommel et al., 2001). More specifically (and seemingly paradoxically, given the positive nature of most experiences and the reluctance of many experiencers to return to the body), those who experience an NDE as the result of a suicide attempt rarely attempt suicide again, in contrast to most suicide attempters. This protective effect may be the result of an increased sense of purpose and appreciation for life (Greyson, 1981, 1992–1993).
Even when the NDE itself has been a positive experience, it can sometimes have negative consequences. NDEs frequently lead to significant changes in values, attitudes, and interests, and family and friends may have difficulty understanding and accepting these changes (Bush, 1991; Flynn, 1986; Greyson, 1997; Insinger, 1991). Also, some people may doubt their sanity in the aftermath of such an unexpected and powerful experience, and they may thus fail to discuss this fear or their experience with others because of a concern that they will be ridiculed or rejected (see, e.g., van Lommel et al., 2001, p. 2043).
Apart from the profound psychological effects that NDEs often have on individual experiencers, the importance of NDEs for psychology lies in their implications for an understanding of the relationship of mind and brain. In particular, it is the continuation and even enhancement of mental functioning at a time when the brain is physiologically impaired that presents problems for the prevailing view of mind-brain relations and thus renders NDEs of particular importance in this regard. In this section, we will review some of the explanatory models that have been proposed for NDEs, paying special attention to how well they can account for the various features of NDEs and especially for enhanced mental functioning.
Many observers have considered NDEs to be a defense against the threat of death. One widespread suggestion is that NDEs are products of the imagination generated to protect oneself when facing the threat of death and constructed from one’s personal and cultural expectations. NDEs do seem to be a universal phenomenon—as we mentioned earlier, they have been reported throughout history and in many cultures—and they may thus be a common human reaction when confronted with death. On the other hand, there are cultural differences, suggesting that prior beliefs may have some influence on the kind of experience a person will have or report. The life review and tunnel sensation, for example, are common in some cultures but rare in others (Kellehear, 1993). Cases in India show some differences in features as compared with Western cases, primarily in the way in which the person reports being taken to an “other” realm and being sent back (Pasricha & Stevenson, 1986). Cases in north India also show differences from cases in south India (Pasricha, 1993).
Other data, however, do not support an expectation theory. Experiences often differ sharply from the individual’s prior religious or personal beliefs and expectations about death (Abramovitch, 1988; Ring, 1984). People who had no prior knowledge about NDEs describe the same kinds of experiences and features as do people more familiar with the phenomenon (Greyson, 1991; Greyson & Stevenson, 1980; Ring, 1980; Sabom, 1982). Young children, who are less likely to have developed expectations about death, report NDEs with features similar to those of adults (Bush, 1983; Gabbard & Twemlow, 1984; Herzog & Herrin, 1985; M. Morse, 1983, 1994a, 1994b; M. Morse, Conner, & Tyler, 1985; M. Morse et al., 1986; Serdahely, 1990). Because many childhood experiences have been recounted only after the child has grown up, and may therefore have been influenced by the adult reporter’s beliefs, Serdahely (1991) compared adult accounts of childhood NDEs with contemporary accounts by children. The features reported did not differ significantly between these two groups
If NDEs are significantly shaped by cultural expectations, we might expect that experiences occurring after 1975, when Moody’s first book made NDEs such a well-known phenomenon, would conform more closely to Moody’s “model” than those that occurred before that date. This does not appear to be the case (Long & Long, 2003). Similarly, a study of 24 experiences in our collection that not only occurred but were reported before 1975 found no significant differences in the features reported, when compared to a matched sample of cases occurring after 1984, except that fewer “tunnel” experiences were reported in the pre-1975 group (Athappilly, Greyson, & Stevenson, 2006).
There may therefore be a core experience underlying the varying details, and it is not the core experience that differs so much as the ways in which people in different cultures describe or interpret what they have experienced. For example, among both Indian and Western cases many people report being met by discarnate persons; but in the West these persons are usually either identified as deceased loved ones or are unrecognized, whereas in India they are often assumed to be messengers of the god of death. Similarly, in both cultures people report that they were sent back because it was “not my time”; but in the West people often feel that they were sent back because of unfinished business, whereas in India they believe that they were sent back because the messengers of death inadvertently took the wrong person (Osis & Haraldsson, 1977/1997; Pasricha & Stevenson, 1986). Other features commonly reported cross-culturally include the sense of being out of one’s body, going to another realm, and seeing a light. There seems, in sum, to be an underlying core experience that is “inevitably cast in the images, concepts and symbols available to the individual” (Roberts & Owen, 1988, p. 611; see also Knoblauch, Schmied, & Schnettler, 2001).6
Related to the “expectation” model is the more recent suggestion that some NDEs may be the product of “false memories,” that is, that “some patients, on hearing about other survivors’ NDEs, would start to imagine what it would have been like if they had had the same experience” (French, 2001, p. 2010). French derives his argument from the observation that four of 37 patients in van Lommel et al.’s (2001) study did not initially report an NDE, but then did report one at a two-year followup interview. Without denying the possibility that a few reported NDEs may be the result of a false memory, we believe that for most this hypothesis is highly unlikely. Even if one discounts the claim of many people reporting NDEs that they had not previously heard about such experiences—something that we are not inclined to do—one also has to consider the fact that many people are reluctant to talk about their experiences with other persons, and may carefully choose when and to whom they do so. In our collection of cases, for example, 57% said that they had been afraid or reluctant to talk about their experience, and 27% never told anyone until more than a year afterwards. Given these observations, we are not at all surprised that four of 37 people in van Lommel et al.’s study might not have reported their experience to the investigators initially.7
In a variation on the idea that NDEs are a universal psychological reaction to the threat of dying, Sagan (1979, 1984) interpreted them—with their features of a dark tunnel, a bright light, and going to another realm—as a memory of one’s birth. C. B. Becker (1982) argued, however, that newborns lack the visual, spatial, or mental capacities to register memories of being born. Even if the implicit assumption here about the dependence of episodic memory upon the brain were to prove inadequate (see Chapter 4), a more important criticism is that many NDEs do not contain the features of a tunnel or a light, and many other common features of NDEs do not seem adequately accounted for by a “birth” model. Furthermore, Blackmore (1983) found that claims of OBEs and of passing through a tunnel to another realm were equally common among persons born by caesarean section and those born by normal vaginal delivery. Grof (1975) and Grosso (1981, 1983) have generalized the birth model and suggested that NDEs reflect an archetype of birth (or rebirth), rather than an actual memory, but it is difficult to see how this theory could be tested empirically.
Noyes and Kletti (1976) suggested that NDEs are a type of depersonalization, in which feelings of detachment, strangeness, and unreality protect one from the threat of death. There are significant phenomenological differences, however, between most NDEs and depersonalization (see, e.g., Gabbard & Twemlow, 1984, pp. 45–59).8 For example, in depersonalization, “the feeling of one’s own reality is temporarily lost” (p. 46), a feeling that does not occur in NDEs. Moreover, many NDEs are described instead as being vividly real. Most experiences of depersonalization are also unpleasant in nature, again in distinct contrast to most NDEs. Furthermore, in depersonalization the person may feel a certain detachment from his or her body without feeling actually out of the body.
Attempts to identify personality traits or variables that predict either the occurrence of an NDE or the number and type of features occurring have generally been inconclusive, although the research has been limited so far to retrospective studies that may not reliably reflect the person’s characteristics before the NDE. Experiencers have collectively been found to be as psychologically healthy as people who have not had an NDE, and they also do not differ in age,9 gender, race, religion, religiosity, intelligence, neuroticism, extroversion, anxiety, or Rorschach measures (Gabbard & Twemlow, 1984; Greyson, 1991; Irwin, 1985; T. P. Locke & Shontz, 1983; Ring, 1980; Sabom, 1982).
Conjecturing that people who experience NDEs may be good hypnotic subjects, remember their dreams more often, and engage easily in mental imagery, some researchers have begun to examine personality variables related to hypnotic susceptibility, dream recall, or imagery. One such characteristic is dissociation. Ring and Rosing (1990) and Greyson (2000) found that near-death experiencers scored higher than a comparison group on a dissociation scale, although their scores were much lower than those of patients with pathological dissociative disorders. Near-death experiencers may therefore be persons who respond to serious stress with dissociative behavior that is adaptive, rather than pathological (Greyson, 2001).
Related to dissociative tendencies may be absorption, or the ability to screen out the external world and focus one’s attention either on selected sensory experiences or on internal imagery (Tellegen & Atkinson, 1974), and fantasy proneness, characterized by frequent and vivid fantasies and even hallucinations, intensely vivid sensory experiences, and eidetic imagery (S. C. Wilson & Barber, 1981, 1983). Empirical data regarding absorption and fantasy proneness among near-death experiencers, however, have been inconclusive. In one study people experiencing an NDE had slightly higher scores on scales of absorption or fantasy proneness, as compared with a control group (Council & Greyson, 1985); but the experiencers’ scores on the measure of fantasy proneness were substantially lower than those of Wilson and Barber’s fantasizers. Ring and Rosing (1990) found no such correlation, although this finding may have been partly the result of using only a brief questionnaire rather than intensive interviews (Lynn & Rhue, 1988). In any case, even a strong relationship between fantasy proneness and NDEs would not demonstrate that NDEs are nothing but fantasies, especially since (as we will discuss later) there are NDEs in which the person has perceived some real, verified event occurring outside the ordinary sensory range. A tendency toward fantasy proneness or absorption might instead reflect an ability to enter more readily into altered states in which the ordinary relationship of consciousness to brain activity and to the external environment has changed.
There have been numerous attempts to explain NDEs in terms of conventional biochemical or neurobiological mechanisms, acting either alone or in conjunction with other putative mechanisms. Most of these proposals are variations on the basic idea that changes in the neurochemistry of the brain, brought on by the physiological or psychological conditions accompanying a close brush with death (whether real or perceived), lead to abnormal neuroelectric activity in certain critical brain areas, usually in the limbic system or temporal lobes, that produces hallucinations. Most of these theoretical models are based on claimed similarities between the phenomenology of NDEs and that of experiences associated with the proposed neurochemical or neuroanatomical mechanisms. We will briefly review here some of these models. We should keep in mind, however, that as researchers have learned more about the variations and complexities of the conditions under which NDEs can occur, there has been a noticeable move away from attempting to find a single common mechanism underlying all NDEs, and toward recognizing that “a multi-leveled interpretation is… the most useful” (Jansen, 1997a, p. 13). Most commentators, therefore, would now acknowledge that these proposals, biological and psychological, are not mutually exclusive and that a variety of factors can lead to the occurrence of an NDE.
One of the earliest and most persistent of the physiological theories proposed for NDEs is that lowered levels of oxygen (hypoxia or anoxia), perhaps accompanied by increased levels of carbon dioxide (hypercarbia), have produced hallucinations (Blackmore, 1993; Lempert, 1994; Rodin, 1980). Although such changes are potentially a factor, particularly among NDEs occurring in connection with cardiac impairment or arrest, NDEs also occur in many circumstances in which changes in oxygen or carbon dioxide levels are unlikely, such as non-life-threatening illnesses, falls, or other near-accidents. Furthermore, despite claims to the contrary, the experiential phenomena associated with such changes are only superficially similar to NDEs. One study frequently cited is that of Whinnery (1997), who compared NDEs to what he called the “dreamlets” occurring in brief periods of unconsciousness induced in fighter pilots by rapid acceleration in a centrifuge (this reduces blood flow, and therefore delivery of oxygen, to the brain). He claimed that some features common to NDEs are also found in these hypoxic episodes, including tunnel vision, bright lights, brief fragmented visual images, a sense of floating, pleasurable sensations, and, rarely, a sense of leaving the body. The primary features of acceleration-induced hypoxia, however, are myoclonic convulsions (rhythmic jerking of the limbs), impaired memory for events just prior to the onset of unconsciousness, tingling in extremities and around the mouth, confusion and disorientation upon awakening, and paralysis (Whinnery, 1997), symptoms that do not occur in association with NDEs. Moreover, contrary to NDEs, the visual images Whinnery reported frequently included living people, but never deceased people; and no life review or accurate out-of-body perceptions have been reported in acceleration-induced loss of consciousness.
Other authors have suggested that, in parallel with lowered oxygen levels, increased levels of carbon dioxide may contribute to NDEs (Blackmore, 1996, p. 74; Jansen, 1997a, p. 19). Again, this hypothesis is based on the purported similarity between NDEs and phenomena reported in connection with the proposed mechanism. For example, M. Morse, Venecia, and Milstein (1989) state that “all the reported elements of NDEs can be produced in the office setting” with inhaled carbon dioxide (p. 48). Only one study, however, is cited in support of this claim (Meduna, 1950). Meduna does mention some features that occur commonly in NDEs (such as a sense of being out of the body, a bright light, a dark void or tunnel, revival of a memory, and a sense of peace, love, or harmony with God); but these seem comparatively rare, isolated, and fragmented in this context. And other important features, such as meeting deceased persons or a life review involving many memories, are not reported. In sum, the overall phenomenology of carbon dioxide inhalation does not so far seem at all comparable to that of NDEs.10
Another important objection to attributing NDEs to anoxia has been noted by van Lommel et al. (2001). If anoxia and related mechanisms play an important role in the generation of NDEs, why do not most cardiac arrest patients report an NDE? Clearly, anoxia is neither a necessary nor a sufficient condition, and some other factor(s) must be involved.
Another early proposal of a physiological mechanism was that the release of endorphins or other endogenous opioids at a time of stress plays a major role in generating NDEs (Blackmore, 1993; D. Carr, 1981, 1982; Saavedra-Aguilar & Gómez-Jeria, 1989). This seemed a reasonable factor to examine, because endorphins are known quickly to produce cessation of pain (Oyama, Jin, & Yamaya, 1980) as well as feelings of peace and well-being, both of which are common features of NDEs. Problems with models based on the release of endorphins or similar substances soon became apparent, however. Most such neurochemicals produce long-lasting effects once they are released; the injection of endorphins in pain patients, for example, produces relief from pain lasting for hours (Oyama et al., 1980). In contrast, the onset and cessation of the NDE and its associated features are usually quite abrupt, with the pain relief lasting only as long as the NDE itself, which may be only seconds.11 Furthermore, although the release of substances such as endorphins might account for the cessation of pain and the feelings of joy and peace, it fails to account for many other important components of NDEs, such as the out-of-body experience, seeing deceased persons, a life review, and the transformative effects.
Other, related models have thus been proposed that might overcome these limitations. Perhaps the most important of these has been the suggestion that a ketamine-like endogenous neuroprotective agent may be released in conditions of stress, acting on NMDA (N-methyl-D-aspartate) receptors located in the upper layers of the cerebral cortex and other central gray-matter structures to block the neural hyperactivation and consequent cell death that would otherwise result from the massive release of glutamate that occurs during stress. Ketamine, an anesthetic agent that selectively occupies NMDA receptors, can at subanesthetic doses produce feelings of being out of the body (Collier, 1972; Rogo, 1984). Moreover, ketamine sometimes produces other features common to NDEs, such as travel through a dark tunnel into light, believing that one has died, or communing with God (Jansen, 1997a, p. 9).
This hypothesis, however, also has problems. First, it is not at all clear that ketamine experiences do in fact resemble NDEs (M. Morse, 1997, p. 61; Strassman, 1997, p. 29).12 Unlike the vast majority of NDEs, ketamine experiences are often frightening and involve bizarre imagery, and patients usually express the wish not to repeat the experience (Collier, 1972; Johnstone, 1973; Strassman, 1997). Most ketamine users also recognize the illusory character of their experience (Fenwick, 1997, p. 45), in contrast to the many NDE experiencers who are firmly convinced of the reality of what they experienced and its lack of resemblance to illusions or dreams. Even if ketamine experiences do resemble NDEs in some respects, many important features of NDEs, such as seeing deceased people or a revival of memories, have not been reported with ketamine. Furthermore, ketamine typically exerts its effects in an otherwise more or less normal brain, while many NDEs occur under conditions in which brain function is severely compromised. We will return to this point later in the chapter.
The need for a more comprehensive and searching comparison between the phenomenology of NDEs and that associated with various purported mechanisms for them becomes even more apparent when we examine another major component of most current physiological theories of NDEs. Behind most of these theories is an assumption that abnormal activity of the limbic system or the temporal lobes, whether produced by anoxia, endorphins, ketamine, or some other mechanism, produces NDE-like experiences. M. Morse et al. (1989), for example, proposed a model in which imbalances in serotonin or other monoamines lead to abnormal activity in the temporal lobes. Saavedra-Aguilar and Gómez-Jeria (1989) suggested that, under conditions of hypoxia and psychological stress, there is temporal lobe dysfunction and the release of endogenous neuropeptides or neurotransmitters, resulting in analgesia, euphoria, and feelings of detachment. They claim that “the list of mental phenomena seen in temporal lobe epilepsy and stereotoxic stimulation of the temporal lobe includes all the NDE phenomena” (p. 209), and they thus describe their theory as “a neurophysiological explanation for NDEs that is based on their striking similarity to temporal lobe epilepsy” (p. 217).
Many people cite electrical stimulation studies, particularly those of the neurosurgeon Wilder Penfield, as justifying this belief in the “striking similarity” between NDEs and temporal lobe epilepsy. For example, M. Morse et al. (1989) refer to the “agents that cause OBEs and NDEs,” namely, “activation of areas of the temporal lobe that have been documented to cause mystical visions, out-of-body sensations, panoramic memories, and vivid hallucinations,” citing Penfield (1955) and Penfield and Rasmussen (1950) in support of this statement (p. 47). We will discuss in more detail below the often-made claim that Penfield and others have produced OBEs by electrical stimulation of the temporal lobes, but two general points merit mention here.
First, electrical stimulation of cortex is massive and grossly unlike ordinary physiological stimulation. It does not, and cannot, result simply in a localized “activation” of the stimulated region. Indeed, as Penfield (1975) himself clearly recognized, its predominant effects are disruption of electrical activity in the immediate vicinity of the electrode, accompanied by abnormal patterns of discharge into additional cortical or subcortical areas to which the stimulated cortex itself is linked by both forward and backward projections. These remote influences, moreover, may be either excitatory or inhibitory in character. The net result, in short, is a poorly controlled, poorly characterized, and spatially widespread pattern of abnormal electrical activity. Similar comments apply to the “electrical storms” associated with epileptic attacks originating in specific cortical regions.
Second, an examination of the experiences reported by Penfield’s subjects, whether during the pre-surgical electrical stimulation studies or during actual epileptic seizures, does not support sweeping claims such as those cited above about the “striking similarity” between NDEs and experiences produced by temporal lobe seizures or stimulation. Most of the experiences Penfield reported in fact bore little resemblance to actual NDEs. They consisted of hearing bits of music or singing, seeing isolated and repetitive scenes that seemed familiar and may have been fragmentary memories, hearing voices, experiencing fear or other negative emotions, or seeing bizarre imagery that was often described as dream-like (Penfield, 1955; Penfield & Perot, 1963, pp. 611–665). Subsequent studies have found similar experiential phenomena, especially fear or anxiety and fragmented, distorted experiences quite unlike NDE phenomenology (Gloor, 1990; Gloor, Olivier, Quesney, Andermann, & Horowitz, 1982).13
Persinger (1989) has also claimed that “a vast clinical and surgical literature… indicates that floating and rising sensations, OBEs, personally profound mystical and religious encounters, visual and auditory experiences, and dream-like sequences are evoked, usually as single events, by electrical stimulation of deep, mesiobasal temporal lobe structures” (p. 234). His sole reference for this strong claim is a paper by Stevens (1982). That paper, however, is confined entirely to descriptions of certain physiological observations made in studies of epileptic patients, and it contains no mention whatever of any subjective experiences or of electrical stimulation studies, much less of “a vast clinical and surgical literature” supporting Persinger’s claim. Persinger goes on to claim that, using weak transcranial magnetic stimulation, he and his colleagues have produced “all of the major components of the NDE, including out-of-body experiences, floating, being pulled towards a light, hearing strange music, and profound meaningful experiences.” However, we have been unable to find phenomenological descriptions of the experiences of his subjects adequate to support this claim, and the brief descriptions that he does provide in fact again bear little resemblance to NDEs (e.g., Persinger, 1994, pp. 284–285).
The discrepancy between Persinger’s claim to have stimulated NDEs and the actual data from his studies is particularly obvious in Persinger (1999). In one study participants reported their experiences by completing a “debriefing questionnaire” consisting of 19 items that Persinger calls “the classic types of experiences associated with these experiments” (p. 96). Nearly all of these items, however, are completely unlike typical features of an NDE, and the few that might be said to resemble them (“I felt the presence of someone”; “I felt as if I left my body”; “I experienced thoughts from childhood”) are too vague to be able to judge their similarity to what is experienced during an NDE. In two tables, however, Persinger gives verbatim descriptions made by two participants during the stimulation experiment (pp. 97–98). Again, neither of these descriptions resembles an NDE. Isolated elements might seem vaguely similar to those of an NDE (“I see a light”; “I see trees”; “I feel I’m not here… not in my body…. I can’t feel it”); but without much more detailed description, the claimed similarity between NDEs and experiences induced by transcranial magnetic stimulation is clearly premature at best.14
Experiences reported in other brain stimulation studies inspired by Pen-field’s work likewise bear little resemblance to NDEs (Horowitz & Adams, 1970, p. 19). Neurologist Ernst Rodin (1989) stated bluntly: “In spite of having seen hundreds of patients with temporal lobe seizures during three decades of professional life, I have never come across that symptomatology [of NDEs] as part of a seizure” (p. 256).
Despite the shaky foundations for assertions that NDEs are similar to experiences produced by abnormal temporal lobe activity, anoxia, ketamine, endorphins, or any other proposed physiological mechanism, most current theories of NDEs are multifactor theories in which these various hypothetical physiological and psychological mechanisms are combined ad lib to account for whatever constellation of features is observed in any given NDE. Blackmore (1984, 1993) and Palmer (1978), for example, have suggested that sensory isolation or increasing malfunction of the body threaten the patient’s body image, leading him or her to feel detached from the body, after which the person’s synesthetic or other imagery abilities produce the illusion of watching what is going on around the body. The release of endorphins leads to analgesia and feelings of joy and peace. With increasing cerebral anoxia, the visual system is compromised, producing the illusion of a tunnel and lights. Temporal-lobe mini-seizures stimulate a revival of memories. Visions of deceased persons and of another realm are hallucinations produced by expectations of what will happen at death.
Although physiological, psychological, and sociocultural factors may indeed interact in complicated ways in conjunction with NDEs, these and all other psychophysiological theories proposed thus far consist largely of unsupported speculations about what might be happening during an NDE. None of the proposed neurophysiological mechanisms have been adequately tested or even shown actually to occur in connection with NDEs. A naturally occurring ketamine-like substance, for example, has not been identified in humans (Strassman, 1997, p. 31). Similarly, the presence of other relevant neurochemicals or seizure activity during an NDE remains wholly conjectural, based entirely on the supposed—but questionable—similarity between experiences they are known to produce and NDEs. Moreover, some of these proposals, such as the role of expectation or the presence and effects of anoxia, have been contradicted by what little data we do have. In short, contrary to confident assertions such as “there is little doubt that the class of experiences that comprise mystical experiences in general, and NDEs in particular, is strongly correlated with temporal lobe activity” (Persinger, 1989, p. 234), there is still very much doubt.15
The most important objection to the adequacy of all existing psychophysiological theories, however, is that mental clarity, vivid sensory imagery, a clear memory of the experience, and a sense that the experience seemed “more real than real” are the norm for NDEs, even when they occur under conditions of drastically altered cerebral physiology. As Parnia and Fenwick (2002) point out, “any acute alteration in cerebral physiology such as occurring in hypoxia, hypercarbia, metabolic, and drug induced disturbances and seizures leads to disorganised and compromised cerebral function… [and] impaired attention,” whereas “NDEs in cardiac arrest are clearly not confusional and in fact indicate heightened awareness, attention and consciousness at a time when consciousness and memory formation would not be expected to occur” (p. 6). Moreover, experiencers of NDEs in connection with cardiac arrest almost invariably retain vivid memories of their experience that change little with the passage of time (van Lommel et al., 2001), despite the fact that memory under such conditions is ordinarily seriously impaired. For most patients the involvement of the hippocampus in temporal lobe epilepsy precludes any memory afterward for what happened during a seizure; “abnormal discharges in the temporal lobe may produce confusional fragments of phenomena sometimes seen in NDEs…. This is a very long way from arguing that seizure discharges in those areas, resulting from brain catastrophe, can give rise to the clearly remembered, highly structured NDE” (Fenwick, 1997, p. 48).
NDEs seem instead to provide direct evidence for a type of mental functioning that varies “inversely, rather than directly, with the observable activity of the nervous system” (Myers, 1891d, p. 638). Such evidence, we believe, fundamentally conflicts with the conventional doctrine that brain processes produce consciousness, and supports the alternative view that brain activity normally serves as a kind of filter, which somehow constrains the material that emerges into waking consciousness. On this latter view, the “relaxation” of the filter under certain still poorly understood circumstances may lead to drastic alterations of the normal mind-brain relation and to an associated enhancement or enlargement of consciousness. To this interpretation of NDEs, which we favor, we now turn.
Most near-death experiencers are convinced that during the NDE they temporarily separated from their physical bodies, and therefore that they may also survive the more permanent separation at death. In our collection, for example, among the people who provided information regarding these features, 81% reported feeling separated from the body during the NDE, and 82% said that the NDE had convinced them of survival after death. We have labeled this interpretation of NDEs a “transcendent” model, at the risk of alienating readers who associate such a word with unscientific beliefs, because the idea that there are aspects of the natural world inaccessible to our ordinary senses and consciousness, but perhaps reflecting some level of reality transcending the ordinary physical world, is not inherently unscientific. Although it certainly contradicts the assumptions of most contemporary psychologists and neuroscientists that the ordinary physical world is the only reality, the direction that physics has taken in the last century amply justifies Myers’s cautionary remark that we should “sit loose” when it comes to making assumptions about the scope and the fundamental character of the natural world (HP, vol. 2, p. 262; see also our Chapter 9).
The popular interest in NDEs clearly derives from their suggestion that mind or consciousness may persist and continue to function even after the death of the brain. In contrast, most NDE researchers have largely ignored this question, undoubtedly because of the widespread acquiescence among psychologists and neuroscientists to the dogma that brain produces mind, or is the mind. Most researchers have concentrated instead on descriptive studies of the aftereffects of NDEs or on speculating about possible neurophysiological and psychological mechanisms, as described above. Several features of NDEs, however, call into question whether current psychological or physiological theories of NDEs will ever provide a full explanation of them.
As we mentioned earlier, perhaps the most important of these features, because it is so commonly reported in NDEs, is the occurrence of full-fledged mentation, either normal or even enhanced mental activity, at times when, according to conventional psychophysiological theory, such activity should be diminishing, or even not possible. Individuals reporting NDEs often describe the experience as being altogether unlike a dream, in that their mental processes during the NDE were remarkably clear and lucid and their sensory experiences unusually vivid, equaling or even surpassing those of their normal waking state.16 Clearly, these are subjective impressions that we cannot verify, but the frequency and consistency of such reports is impressive. Furthermore, an analysis of cases in our collection in which we were able to examine contemporaneous medical records showed that, in fact, people reported enhanced mental functioning significantly more often when they were actually physiologically close to death than when they were not (Owens et al., 1990).
Another example of enhanced mental functioning during an NDE is a rapid revival of memories that sometimes extends over the person’s entire life. Myers (1895d) had called attention to this phenomenon when he described “the occasional revival during drowning—or, in Charles Darwin’s case, during a fall from a wall—of a series of life memories both swifter and fuller than conscious effort could have supplied” (p. 354). The philosopher Henri Bergson likewise recognized not only the occurrence but the theoretical importance of this phenomenon (e.g., Bergson, 1908/1991, p. 155). It is worth noting here also that such revivals of memory may be frequent (Myers, 1895d, p. 354). For example, an analysis of computer-coded NDE cases in our collection showed that in 24% of them there was a report of some degree of revival of memories during the NDE. We emphasize, moreover, that in contrast to the isolated and often just single brief memories evoked during cortical stimulation, those revived during an NDE are frequently described as being “many” or even as an almost instantaneous “panoramic” review of the person’s entire life.17
Reports of NDEs from widely divergent cultures and times support the view that enhanced mental functioning can occur under conditions in which it would not be expected on current models of mind and brain. However one interprets the crosscultural differences, perhaps the most important finding from such studies is that people have consistently reported, from different parts of the world and across different periods of history, having had complicated cognitive and perceptual experiences at times when brain functioning was severely impaired.
Another important feature of NDEs that current theoretical models cannot adequately account for is the experience of being out of the body and perceiving events that one could not ordinarily have perceived. Near-death experiencers often report that during the NDE they viewed their bodies as if from a different point in space. A recent analysis of cases in our collection showed that 48% of the respondents reported seeing their physical bodies from a different visual perspective. Many of them also reported witnessing events going on in the vicinity of their body, such as the attempts of medical personnel to resuscitate them at the scene of an accident or in an emergency room.
Like most other features of NDEs, many of these out-of-body perceptions are entirely subjective, providing no direct evidence that the person has in fact either been separated from the body or observed contemporaneous circumstances. Some commentators (e.g., Blackmore, 1993; Saavedra-Aguilar & Gómez-Jeria, 1989; Woerlee, 2004) have argued that the belief that one has witnessed events going on around one’s body is a retrospective imaginative reconstruction attributable to a persisting ability to hear, even when unconscious, or to the memory of objects or events that one might have glimpsed just before losing consciousness or while regaining consciousness, or to expectations about what was likely to have occurred.
Such explanations are inadequate, however, for several reasons. First, memory of events occurring just before or after loss of consciousness is usually confused or completely absent (Aminoff, Scheinman, Griffin, & Herre, 1988; Parnia & Fenwick, 2002; van Lommel et al., 2001). Second, claims that adequately anesthetized18 patients retain any significant capacity to be aware of or respond to their environment in more than rudimentary ways—let alone to hear and understand—have in general not been substantiated. Since the earliest years of chemical anesthesia, there have been occasional reports of patients who appeared to display some degree of memory for events that occurred during surgery (Cheek, 1964, 1966). Most of these could be attributed to insufficient anesthesia, but not all (Levinson, 1965, 1990). There were also some intriguing early clinical case reports indicating that patients sometimes showed agitation following surgery in which negative comments had been made about them or their prognosis. More benignly, other patients were reported to recover more quickly when given positive suggestions during the surgery to the effect that they would do so (D. Schacter, 1996, p. 172).
Even an early review questioned the claim that people might retain some auditory perception under general anesthesia, finding numerous methodological problems with studies purporting to show this (Trustman, Dubovsky, & Titley, 1977). Moreover, more recent and better controlled studies have also not substantiated such claims (Ghoneim & Block, 1992, 1997). Studies of memory and awareness in anesthesia have been highly inconsistent, and there is no convincing evidence for adequately anesthetized patients having any explicit, or conscious, memory of events during the surgery (apart from patients who have reported such memories in connection with an NDE). What positive evidence there is for “learning and memory” during adequate general anesthesia mainly involves implicit memory phenomena such as perceptual and mnemonic “priming” and other low-level effects, which are known not to require participation of the brain systems normally involved with explicit declarative memory (Bonke, Fitch, & Millar, 1990; D. Schacter, 1996). Moreover, even these low-level effects occur inconsistently, and they depend in complex and poorly understood ways on factors such as the nature and dosage of the specific anesthetic agents used, their interactions, the specific types of memory tasks used and their conditions of administration, and the many semi-controllable stimulus events occurring during the surgery itself. Ghoneim and Block (1997) summarize the situation as follows: “We can speculate that unconscious memory occurs only in few patients, only some of the time, and during light levels of anesthesia. Learning may be more perceptual than engaging in elaborate processing of complex information and may be limited to single, relatively familiar words. Memory may be more evident if tested as soon as possible after surgery” (p. 406).
In sum, such studies as we have afford little hope for explaining NDE reports involving complex sensory experiences of events occurring during general anesthesia in terms of knowledge acquired by the impaired brain itself during the period of unconsciousness. Note also that any such explanatory claims are even less credible when, as commonly happens, the specific sensory channels involved in the reported experience have been blocked as part of the surgical routine—for example, when specifically visual experience is reported by a patient whose eyes were taped shut during the relevant period of time. We will discuss the theoretical significance of general anesthesia in relation to NDEs more fully later in this chapter.
Another reason for being cautious about attributing claims of out-of-body perceptions to retrospective reconstruction is a study by Sabom (1982), carried out specifically to examine this hypothesis. Sabom had interviewed 32 patients who reported NDEs in which they seemed to be watching what was going on around their body. Most of these were cardiac patients who were undergoing cardiopulmonary resuscitation (CPR) at the time of their NDE. Sabom then interviewed 25 “control” patients, “seasoned cardiac patients” who had not had an NDE during their previous cardiac-related crises, and asked them to describe a cardiac resuscitation procedure as if they were watching from a third-person perspective. Among all these patients, 80% of the “control” patients made at least one major error in their descriptions, whereas none of the NDE patients made any. Moreover, six of the 32 NDE patients related accurate details of idiosyncratic or unexpected (to them) events during their resuscitation (pp. 87–115). For example, one man, who developed ventricular fibrillation in the coronary care unit, said (among many other things) that the nurse picked up “them shocker things” and “touched them together,” and then “everybody moved back away from it [the defibrillator]” (p. 96). As Sabom explained, rubbing the defibrillator paddles together to lubricate them and standing back from the defibrillator to avoid being shocked are common procedures (p. 98).
An even more difficult challenge to ordinary psychological or physiological theories of NDEs comes from cases in which experiencers report that, while out of the body, they became aware of events occurring at a distance or that in some other way would have been beyond the reach of their ordinary senses even if they had been fully and normally conscious. In our collection, 60 people have described being aware of events occurring outside the range of their physical senses. K. Clark (1984) and Owens (1995) each published a case of this type, and we have reported on 15 cases, including seven cases previously published by others and eight from our own collection (Cook [Kelly], Greyson, & Stevenson, 1998; E. W. Kelly, Greyson, & Stevenson, 1999–2000). Some of these accurate perceptions included unexpected or unlikely details, such as a woman in childbirth who reported being out of her body and seeing her mother in the waiting room smoking a cigarette; according to the daughter, the mother (a non-smoker) “admitted much later that she had ‘tried’ one or two because she was so nervous!” (Cook [Kelly] et al., 1998, p. 391). Additionally, Ring and Cooper (1997, 1999) reported 31 cases of blind individuals, nearly half of them blind from birth, who experienced during their NDEs quasi-visual and sometimes veridical perceptions of objects and events. Many of these people, like other NDE experiencers, also said that they saw a bright light.
A frequent—and valid—criticism of these reports of perceptions of events at a distance from the body is that they often depend on the expe-riencer’s testimony alone. It is a frustrating fact that in many such cases people who could possibly provide verification or corroborating testimony have either moved away or died by the time of the investigation of the case. The weakness of the testimony for the majority of these claims has encouraged commentators such as Blackmore (1993, p. 262) to refuse to accept any reports of such cases as evidential, on grounds that “many of these claims are based on purely anecdotal evidence and very few have any independent corroboration” (Blackmore, 1996, p. 75) . However, some cases have been corroborated by others (K. Clark, 1984; H. Hart, 1954; Ring & Lawrence, 1993). Van Lommel et al. (2001, p. 2041), for example, reported a case in which a cardiac arrest victim was brought into the hospital comatose and cyanotic, and even after restoration of his circulation, he remained in a coma and on artificial respiration in the intensive care unit for more than a week. When he regained consciousness and was transferred back to the cardiac care unit, he immediately recognized one of the nurses, saying that this was the person who had removed his dentures during the resuscitation procedures. He said further that he had watched from above the attempts of hospital staff to resuscitate him in the emergency room, and he described “correctly and in detail” the room and the people working on him, including the cart in which the nurse had put his dentures. The nurse corroborated and verified his account. We ourselves (Cook [Kelly] et al., 1998, pp. 399–400) have reported a case of this type in which, in addition to numerous other details such as encountering a barrier, seeing a light and tunnel, feeling joy and peace, and meeting two deceased relatives, the patient described leaving his body and watching the cardiac surgeon “flapping his arms as if trying to fly.” The surgeon verified this detail by explaining that, after scrubbing and to keep his hands from possibly becoming contaminated before beginning surgery, he had developed the idiosyncratic habit of flattening his hands against his chest, while rapidly giving instructions by pointing with his elbows.
Many people who approach death and recover report that, during the time they seemed to be dying, they met deceased relatives and friends. Among the cases in our collection 42% of experiencers reported meeting one or more recognized deceased acquaintances during the NDE. Such experiences have been widely viewed as being “merely” hallucinations, caused by drugs or other physiological conditions or by the person’s expectations or wishes to be reunited with deceased loved ones at the time of death. Nevertheless, a closer examination of these experiences indicates that such explanations are not adequate (E. W. Kelly, 2001).
For example, people close to death are more likely to perceive deceased persons than do healthy people, who, when they have waking hallucinations, are more likely to perceive living persons (Osis & Haraldsson, 1977/1997). Near-death experiencers whose medical records show that they really were close to death also were more likely to perceive deceased persons than experiencers who were ill but not close to death, even though many of the latter thought they were dying (E. W. Kelly, 2001). Moreover, numerous people, both those near death and those not near death, also perceive figures other than known deceased persons during the NDE, most of these being unrecognized. If expectation alone were driving the process, people would presumably recognize the hallucinatory figures, either as actual deceased or living people or as known religious figures, more often than was in fact the case. In our collection, however, few people reported perceiving specific religious figures such as Jesus.19 Even fewer reported perceiving living persons, even though many of them commented that it was the thought of living people whom they were leaving that made them return to their bodies. Only two people reported perceiving deceased pets, much to the disappointment of some of those who did not. We have found that people do more often perceive deceased people with whom they were emotionally close, a finding consistent with the expectation theory—but, we add, equally consistent with that of survival after death. Nonetheless, in one-third of the cases the deceased person was either someone with whom the experiencer had a distant or even poor relationship or someone whom the experiencer had never met, such as a relative who died long before the experiencer’s birth (E. W. Kelly, 2001). For example, van Lommel (2004, p. 122) reported the case of a man who had an NDE during cardiac arrest in which he saw his deceased grandmother and an unknown man. He later learned from his dying mother that he had been born out of an extramarital affair and that his father had been killed during World War II. Shown a picture of his biological father, he immediately recognized him as the man he had seen in his NDE, 10 years previously. We have a similar case in our collection, in which a man reported seeing five unknown men, one of whom he recognized several months later in a photograph as the deceased father of a girlfriend (later his wife), whom he had never met.20
As we mentioned earlier, the inability of any one conventional physiological or psychological hypothesis to account for all NDEs, or even all features of NDEs, has led many researchers to propose multifactorial theories, combining psychological and physiological mechanisms ad lib. The need, however, for increasingly complicated and composite explanations, together with the lack of an adequate empirical foundation for any of them, has led us to suggest that we should not rule out categorically that NDEs are essentially what many experiencers think they are—namely, evidence that they have temporarily separated from their body and, moreover, may survive the permanent separation that occurs at death (Cook [Kelly] et al., 1998; E. W. Kelly et al., 1999–2000). When each is examined alone and in isolation, the features described in this section, as well as other NDE features, may seem potentially explainable by some psychological or physiological hypothesis, despite the paucity of supporting evidence. When several features occur together, however, and when multiple layers of explanation must be added on ad hoc to account for them, these explanations become increasingly strained.
A case which conspicuously exemplifies numerous features difficult to account for in conventional psychophysiological terms is that of Pam Reynolds, reported in detail by Sabom (1998, pp. 37–51). This case is also particularly important because Sabom, a cardiologist, was able to obtain verification from participating medical personnel concerning some critical details of the operation that the patient reported observing during her experience.
This patient underwent a procedure called hypothermic cardiac arrest (Spetzler et al., 1988; Weiss et al., 1998; M. D. Williams, Rainer, Fieger, Murray, & Sanchez, 1991) for removal of an extremely large aneurysm deep in her brain that would be fatal if it ruptured and that was inaccessible by ordinary neurosurgical techniques. Her eyes were first lubricated and taped shut; then, following induction of general anesthesia (Forane, plus 50/50 nitrous oxide/oxygen), she was heavily instrumented to permit accurate monitoring of her vital functions. In addition to standard EEG and EKG monitors, special catheters provided measures of pulmonary arterial blood pressure and flow, as well as urinary temperatures in her bladder. Additional temperature recordings were taken from her esophagus, and later from the surface of her exposed brain. Molded speakers placed in her ears, and occluding the ear canals, were used to deliver loud clicks,21 which permitted monitoring of her brainstem auditory evoked potentials. After about 90 minutes, the surgery proper began. Her skull was opened, and she was connected to a cardiopulmonary bypass machine. The circulating blood was rapidly chilled, her core temperature dropping 25° in about 10 minutes. At this point her heart, which had begun to behave erratically, was deliberately stopped with an intravenous bolus of potassium chloride. Her EEG went flat. The brainstem evoked responses further weakened as cooling progressed, and ceased entirely at 60°. She had reached “total brain shutdown.” At this point, the surgical table was tilted up, and the blood was drained from her brain so that the aneurysm could be safely removed. Following repair of the aneurysm, her blood was warmed and returned to her body and her vital functions gradually restored. During the resuscitation procedures, however, her heart went into ventricular fibrillation, and she had to be shocked twice (50/100J) to restore normal rhythm.
Although the shutdown of her normal physiological functioning was carefully controlled by the medical team, by all conventional criteria this patient could be considered clinically dead during the main part of this procedure: Her electroencephalogram (EEG) was totally flat, her brainstem auditory evoked potentials had ceased, and blood was completely absent from her brain. Nevertheless, the patient reported an unusually detailed, prolonged, and continuous NDE. The experience also included some verifiable features: First, despite having speakers in her ears that blocked all external sounds with 95 dB clicks, the experience began when she heard the sound of the special saw used to cut into her skull (a sound that she, a musician, identified as a natural “D”). She then seemed to leave her body and, from a position near the neurosurgeon’s shoulders, was able to see (and subsequently describe) the saw itself. She also noted the unexpected (to her) way in which her head had been shaved, and she heard a female voice commenting that her veins and arteries were small. At some point she felt herself being pulled along a “tunnel vortex” toward a light. She also heard her deceased grandmother’s voice, and then she saw numerous deceased relatives, all of them permeated by an “incredibly bright” light. Told by her relatives that she had to go back, and thinking about the young children she would be leaving, she reluctantly returned to her body. She also reported that “when I came back, they were playing ‘Hotel California’ and the line was ‘You can check out anytime you like, but you can never leave’“—a choice of music that she later laughingly told one of her doctors had been “incredibly insensitive.”
Although many of the features of her experience were subjective and unverifiable, some were not. Her description of the unusual saw was verified by the neurosurgeon and by photographs of it obtained by Sabom. Also, as the patient had heard, at the time the cardiopulmonary bypass procedure was being started, the cardiac surgeon (a female) had commented that the right femoral vessels were too small to support the bypass, so that she had to prepare the left leg. Although at the time this comment was made the patient’s brainstem auditory evoked potentials had not yet disappeared, the molded speakers in her ears themselves, let alone the 95 dB clicks, would have made it impossible for her to hear the comment in the ordinary way, even had she been fully conscious at that moment.
Equally importantly, the patient reported the kind of mentation that we described earlier: She said that during her experience she was not only aware, but “the most aware that I think I have ever been in my life” (Sabom, 1998, p. 41). She further commented that her vision “was not like normal vision. It was brighter and more focused and clearer than normal vision” (p. 41) and that her hearing “was a clearer hearing than with my ears” (p. 44).
The case is not perfect. The details were not published for several years after the experience occurred. More importantly, the verifiable events that she reported observing in the operating room occurred when she was anesthetized and sensorially isolated but before and after the period of time in which she was clinically “dead.” Further, it is impossible to tell exactly when during the procedure she had the experience of going into a tunnel, seeing a bright light, and conversing with her deceased relatives. Her description of the experience suggests (although of course it cannot prove) that it was continuous from the time she first heard the surgeon’s saw (over an hour after she had been anesthetized) until she returned to her body and heard the song “Hotel California,” near the end of the procedure, some 5lA hours later, when younger assistants had taken over from the surgeons and the background music was changed to rock music (Sabom, 1998, p. 47). Some parts of Pam’s experience may therefore have occurred during the time in the procedure when she was clinically “dead” or near the end of the procedure, when she suddenly went into ventricular fibrillation. We cannot, however, say with certainty that any part of her NDE actually occurred during the period when she was clinically “dead.” Even so, the extremity of her condition and her heavily anesthetized state throughout the entire procedure casts serious doubt on any view of mind or consciousness as unilaterally and totally dependent on intact physiological functioning.
The few shortcomings in this case simply highlight the need for inquiring about the experiences of other patients who have undergone hypothermic cardiac arrest or similarly drastic procedures. A major priority for future research on NDEs is to identify and study experiences that occur in conjunction with heavily monitored surgical procedures, especially cardiac procedures involving close monitoring of electrical brain activity, blood gases, neurochemical levels, or other physiological measures.
Most of the proposed explanations for NDEs assume that they are the product of a “dying brain” (e.g., Blackmore, 1993; Vaitl et al., 2005, p. 102). As we have said earlier and will discuss in more detail below, one of the things that makes NDEs so important is that many of them do occur at a time the person is physiologically near death. Nonetheless, as we also pointed out earlier, many of them do not occur when the person is dying. Moreover, NDEs are by no means an isolated phenomenon. All features occurring in connection with NDEs occur in the context of other kinds of experiences in which the brain is certainly not “dying.” Before we can accept any explanation of NDEs as adequate, we will need far more information than we now have concerning the actual—as opposed to conjectured—physiological and psychological conditions under which they take place. Clearly, however, they will never be understood until they are examined together with these other experiences, occurring under different conditions, that share their features. We therefore turn now to some of those other experiences.
One phenomenon obviously relevant to NDEs is the out-of-body experience (OBE). In an OBE a person’s consciousness is experienced as having separated from the body, but also as continuing to function normally. The OBE is a frequent feature of NDEs, and there is some evidence that it represents an early stage that may develop into a more complex NDE with additional features if the condition is prolonged (R. Lange, Greyson, & Houran, 2004, p. 167). As a result, many of the early collections of reports of OBEs included what we would now call NDEs because they occurred in the context of a medical or life-threatening condition (e.g., Crookall, 1964, 1972; Green, 1968b; Muldoon & Carrington, 1951/1969). On the other hand, many OBEs occur in non-medical contexts, and many NDEs do not include OBEs. Thus, it seems likely that neither OBEs nor NDEs are a subset of the other, but that both instead are manifestations of a larger class of experiences in which there has been an alteration in the ordinary experience of the self in relation to the body and the external environment.
A typical OBE is one that comes from our own collection, in which a man competing in a triathalon, after completing the swimming segment and beginning the bicycling segment, suddenly and briefly seemed to himself to be above the scene, watching the riders below, including himself, with no apparent ill effect on his ability to ride the bicycle. A more dramatic but less typical case is one from the classical literature that is frequently cited, the Wilmot case (E. M. Sidgwick, 1891, pp. 41–46; also cited in HP, vol. 1, pp. 682–685). In 1863 Mr. Wilmot and his sister Miss Wilmot were on a ship traveling from Liverpool, England, to New York, and for much of the journey they were in a severe storm. More than a week after the storm began, Mrs. Wilmot, in Connecticut and worried about the safety of her husband, had an experience, while she was awake during the middle of the night, in which she seemed to go to her husband’s stateroom on the ship, where she saw him asleep in the lower berth and another man in the upper berth looking at her. She hesitated, kissed her husband, and left. The next morning Mr. Wilmot’s roommate asked him, apparently somewhat indignantly, about the woman who had come into their room during the night. Miss Wilmot added her testimony, saying that the next morning, before she had seen her brother, the roommate asked her if she had been in to see Mr. Wilmot during the night, and when she replied no, he said that he had seen a woman come into their room in the middle of the night and go to Mr. Wilmot.22
The incidence of OBEs among the general population is difficult to determine, because many of the estimates have been based on questionnaire studies in which there has been no followup or investigation of the “Yes” responses to learn whether the experience truly qualified as an OBE. A tentative estimate, however, is that at least 10% of the general population has experienced one or more OBEs.23
As with NDEs, theories about OBEs have generally become polarized between conventional psychophysiological theories and a transcendent or “exteriorization” model in which consciousness really does function outside the body. Psychophysiological theories typically suggest that seizures or other abnormal activation of areas of the brain (usually the temporal lobes and adjacent structures) produce alterations in body perceptions or schemata, leading to depersonalization, OBEs, or “autoscopy” (experiences in which the person sees an hallucinatory double of him- or herself in external space; see below). As we mentioned earlier, research frequently cited in support of a model in which abnormal temporal lobe electrical activity produces an OBE is that of neurosurgeon Wilder Penfield (e.g., Penfield, 1955, 1958a, 1958b; Penfield & Erickson, 1941; Penfield & Perot, 1963). Penfield is widely reported as having produced OBEs and other NDE-like phenomena in the course of stimulating various points in the exposed brains of awake epileptic patients being prepared for surgery (e.g., Blackmore, 1993, pp. 212–213; M. Morse et al., 1989, p. 47; Neppe, 1989, p. 247; Tong, 2003). Only two out of his 1132 patients, however, reported anything that might be said to resemble an OBE: One patient said: “Oh God! I am leaving my body” (Penfield, 1955, p. 458). Another patient said only: “I have a queer sensation as if I am not here…. As though I were half and half here” (Penfield & Rasmussen, 1950, p. 174). In later studies at the Montreal Neurological Institute (where Penfield had conducted his studies), only one of 29 patients with temporal lobe epilepsy reported “a ‘floating sensation’ which the patient likened at one time to the excitement felt when watching a football game and at another time to a startle” (Gloor et al., 1982, pp. 131–132). Such experiences hardly qualify as phenomenologically equivalent to OBEs.
Saavedra-Aguilar and Gómez-Jeria (1989) have similarly claimed that OBEs “appear frequently in TLE [temporal lobe epilepsy]” (p. 214), and they cite J. A. M. Frederiks (1969) as the reference for this statement. However, Frederiks made no mention at all of OBEs in connection with temporal lobe epilepsy (although he did discuss autoscopy—discussed below—which is related but not identical to OBEs). Perhaps more importantly, Frederiks specifically denied that any such disorders of the body schema have been localized: “No well-defined anatomical localization has yet been established nor is any likely to be established because in most cases a large, bilateral or diffuse cerebral damage is present or diffuse cerebral dysfunction can be assumed…. The body schema can in my opinion not be strictly localized; it is one of the many products of the total function of the nervous system” (pp. 233, 212).
More compelling evidence for possible physiological factors associated with the occurrence of OBEs and related phenomena is summarized in a review by Devinsky, Feldmann, Burrowes, and Bromfield (1989). They reported on 10 patients of their own (identified in a prospective study of 158 seizure patients) who had experienced OBEs or autoscopic phenomena in connection with their seizures, and they also reviewed 18 earlier reports involving an additional 33 seizure patients with similar experiences. Of these 43 patients, 18 reported OBEs and 25 reported autoscopic experiences.24 Of 30 identifiable seizure foci, only 18 involved the temporal lobes. These could occur on either or both sides, and were often accompanied by additional seizure activity, disease, or injury in frontal, parietal, or occipital cortex. These complex clinical findings also did not appear to differ in any clear or consistent way between OBE and autoscopy cases.
More recently, Olaf Blanke and colleagues (Blanke, Landis, Spinelli, & Seeck, 2004; Blanke, Ortigue, Landis, & Seeck, 2002) have provided detailed reports, including some neuroimaging results, for six neurological patients, three of whom had experiences, which Blanke et al. describe as OBEs, associated with seizure activity or with direct electrical stimulation of the exposed cortex. Three additional patients (as well as one of the three OBE patients) had autoscopic experiences in association with seizures or (in one case) with a possible ischemic attack during migraine. The imaging and stimulation results suggested involvement of a common cortical region encompassing the junction of temporal and parietal cortex (TPJ), a region which is thought normally to be involved in the integration of vestibular information with tactile, proprioceptive, and visual information regarding the body and its location in perceptual space. On this basis, the authors hypothesized that all such experiences involve failures of this integration, caused by “paroxysmal cerebral dysfunction of the TPJ in a state of partially and briefly impaired consciousness” (Blanke et al., 2004, p. 243).
The empirical findings of Blanke and his colleagues are certainly significant, but their theoretical conclusions seem to us premature. First, the purported localization of neurologic abnormalities is less than clear and compelling. The identified region, the TPJ (encompassing the anterior part of the angular gyrus and the posterior part of the superior temporal gyrus), is only a region of “mean overlap” of individual lesions that are distributed much more widely. Furthermore, the appearance of localization derives in part from mapping results from the very different brains of all five patients onto the left hemisphere of only one of them (Blanke et al., 2004, Figures 2 and 4). In one patient no overt anatomical or functional defect could even be identified. Similarly, of Devinsky et al.’s (1989) 10 patients, three were specifically said to have fronto-temporal lesions or EEG abnormalities, two showed “generalized 3/s spike and wave discharges,” and one showed no overt anatomical, neurological, or EEG abnormalities. Among the 29 additional patients for whom any information was available, the seizures of two were specifically localized to the anterior temporal lobe (which does not involve the TPJ), and only about a dozen are characterized in terms even loosely consistent with the Blanke et al. hypothesis. Furthermore, there is no clear lateralization. Among Blanke et al.’s patients and those reviewed by Devinsky et al., the location of identifiable foci was almost evenly split between the left and right hemispheres. Moreover, the studies of Gloor and his colleagues led them to “conclude that experiential phenomena, including perceptual ones, are more likely to occur in response to limbic than to temporal neocortical stimulation or seizure discharge” (Gloor et al., 1982, p. 140; see also Gloor, 1990).
Second, the generalization from these few patients with identified neurological problems to all persons experiencing an OBE, most of whom have no known neurological problem, is purely conjectural. We agree that abnormal activity in the TPJ region or some other location may sometimes contribute to the occurrence of an OBE; the fact that the experiences of some of these patients could be altered or abolished by therapeutic intervention (surgery or medication) provides evidence for this. Nevertheless, to conclude that any such activity pattern is necessary, in general, seems to us quite doubtful. All of the patients reported by Devinsky et al. (1989) and five of the six patients of Blanke et al. (2004) suffered moderate to severe neurological pathology; but such pathology appears generally to be absent, and certainly has not been demonstrated to be present, in the vast majority of persons who spontaneously experience OBEs. A special OBE subject studied by Tart (1968), for example, was specifically found to have a normal clinical EEG.
Furthermore, even if we assume that cortex in the vicinity of the TPJ is involved somehow in the production of at least some OBEs, that cortex itself is probably not producing them. This is because both seizure activity and direct electrical stimulation of a particular region of association cortex typically lead to disruption of whatever patterns of neuroelectric activity would otherwise be going on there. That is, the failure of the normal integration could be explainable by these factors, but not the production of the abnormal one (the OBE). Something else is doing that.
Moreover, there are many patients with similar neurological problems or patterns of seizure activity who do not experience OBEs. In Devinsky et al.’s prospective study (1989), only 10 (or 6.3%) of 158 seizure patients reported OBEs or autoscopy. Furthermore, although the 43 patients in the Devinsky et al. review had suffered numerous seizures, often over a period of many years, 10 had only one experience, and 15 others had five or fewer (p. 1082). Only two of Penfield’s 1,132 patients reported even vaguely OBE-like phenomena. Moreover, as we mentioned earlier, some of Devinsky et al.’s patients had an OBE, not during an ordinary seizure, but only at a time when they were near death, or thought they were dying. These findings clearly suggest that localized abnormal activity in the brain is not only not necessary, but also not in general sufficient to produce the change in perceptual locus that is an OBE. At the very least, the sufficient neurological conditions for OBEs have not yet been fully identified.
Finally, Blanke and his colleagues, and others who have focused on the role of temporal lobe activity in the production of OBEs, have not even begun as yet to deal with certain deeper and more difficult aspects of the OBE. For example, even if we are able to associate OBEs with a certain region of the brain—something we are far from doing yet—such localization cannot account for the occurrence in many cases of veridical perceptions during loss of consciousness. More generally, it cannot account for the occurrence of any complex perception or mentation at a time when the abnormalities in brain functioning would normally abolish consciousness. As Devinsky et al. (1989) themselves appropriately caution, “an unresolved problem involves… the paradox of apparent consciousness during the seizure” (pp. 1087–1088). To equate OBEs with pathological “body illusions,” as Blanke et al. do, seems to us to beg the question of the nature of these experiences by ignoring the complexity of their physiological, psychological, and phenomenological aspects. In short, studies such as that of Blanke et al. and Devinsky et al. have not provided anything like a complete and verified neurophysiological account of the OBE, but rather some preliminary findings and hypotheses to be pursued in further work.25
The polarization between those who think we must choose between an exclusively psychophysiological theory on the one hand or, on the other, a monolithic theory of OBEs as evidence for the separability of consciousness and the body seems to us too narrow a view. Before suggesting an alternative way of thinking about the problem, however, we should briefly review additional aspects of OBE cases that suggest the need for a theory that, while not superseding standard psychophysiological models, goes beyond them.
The cases that present the most serious challenge to explaining OBEs in conventional terms are those that involve psi,26 including the veridical perception of some event happening at a distance such as we saw in the Wilmot case. Blackmore (1982) correctly acknowledged that “a purely psychological theory of the OBE cannot directly account for paranormal phenomena and if they occur they demand explanation.” As we pointed out earlier, however, she refuses to accept the evidentiality of any such case. She goes on to conclude that “my guess” is that psychological theories of OBEs will predominate, that these theories will simply “ignore psi altogether,” and that “the question of paranormal phenomena will quietly be dropped” (p. 243). This is certainly one way of handling the problem of reports that conflict with one’s beliefs. But can these reports be dismissed and “ignored” so cavalierly?
Clearly, not all OBEs—even those with impressive phenomenology—are veridical in character. A particularly striking reminder of this is an experience described by Roll (Coly & McMahon, 1995, pp. 118–119). In a vividly realistic OBE, he seemed to leave his body, travel to another part of the house, and see details of the room, including a shadow cast by the moon on the rug. Returning to his body and waking up, he went into the room, but found that there was no moonlight. He concluded that, because the details of his experience did not correspond to the actual physical environment, “this was a mental world. I was in the world that I pictured.”27 Most OBEs similarly provide no evidence that they are anything more than unusually vivid subjective experiences.
Nonetheless, not all OBEs are entirely subjective in nature; the Wilmot case is hardly unique (see, e.g, Cook [Kelly] et al., 1998; E. W. Kelly et al., 1999–2000, for reports of some NDEs that involved both OBEs and perception of events at a distance). H. Hart (1954) conducted an analysis of 288 published OBE cases in which the person reported perceiving events during the experience that he or she could not have perceived in the ordinary way. The 288 cases were all published with a description sufficient to show that, in principle, the experience fit the criteria for perception of a real event occurring at a distance. Most significantly, however, in 99 of these cases the events in question had been verified as having occurred, and the experience had been reported to someone else before that verification occurred. In many of these cases the testimony of the experiencer remains uncorroborated, and even in the corroborated cases it is often possible to poke holes in the testimony, since few of them include a written record of the experience made before the event was verified. Nevertheless, the large numbers of claims of veridical OBEs, both corroborated and uncorroborated, suggest the need for a response more robust than “quietly dropping” them.
An alternate explanation for these veridical cases might be, not that the person’s consciousness in some sense literally left the body and traveled to the distant location, but that the person learned about the event in question by some psi process such as telepathy or clairvoyance, and then incorporated that knowledge into the OBE, which was simply an added hallucination. The evidence for psi from both experimental and field studies is sufficient to make this a plausible theory for many, perhaps even most, of the veridical cases. Nevertheless, another sub-group of OBEs that strains even this explanation is a group commonly called “reciprocal apparitions,” again exemplified by the Wilmot case. In such cases, while one person is deliberately trying to “project,” or is having a spontaneous OBE, or is having a dream in which he or she seems to go to a distant location, a person at that location, unaware of the first person’s experience, sees an apparition of that person. H. Hart (1954) summarized 30 such cases that had been published up to that time (see also H. Hart & Hart, 1933). In a recent study by one of us (EWK) in which an unselected sample of people was asked about a variety of unusual experiences they may have had, five cases of this kind were reported. In one, for example, a nurse became friends with a quadraplegic man who required several hospitalizations for pneumonia and other complications. During one of these hospitalizations, the nurse, feeling guilty that she had not recently visited this patient, had a dream in which she seemed to go to him in the hospital, stood at the end of his bed, and told him to keep fighting. Shortly afterward, the patient’s sister told this nurse that he had reported seeing her standing at the foot of his bed, telling him to keep fighting. None of these five cases are fully investigated or corroborated yet, but the number of them reported clearly suggests that such experiences have been, and still are being, reported in sufficient quantity to warrant taking them seriously.
In a few individuals, OBEs sometimes occur repeatedly or even under some degree of voluntary control, an important property that makes them potentially amenable to observation under controlled conditions. There have so far been only a few such studies attempting to examine veridical perceptions during OBEs. The most well known of these is Tart’s (1968) study of “Miss Z,” a woman who had frequent sleep-related OBEs. She was brought into Tart’s lab for four nights, where she was connected to an EEG machine and asked to try, if she had an OBE, to read a five-digit number that Tart randomly selected and placed as a target on a shelf out of the range of her normal sight. She succeeded completely on one occasion, but, as Tart rightly concluded, “this evidence is not conclusive,” since there was a remote possibility that she might subliminally have been able to see the target reflected in the glass surface of a clock.28 Interestingly, Miss Z’s OBE experiences occurred in conjunction with a fairly well-defined physiological pattern, developing out of Stage 1 sleep and consisting primarily of low-voltage “alphoid” EEG dominated by slow alpha frequencies. Moreover, the rapid eye movements characteristic of dreaming were absent. Miss Z unfortunately moved away shortly after this promising experiment, and Tart was unable to conduct further work with her.
In another series of experiments, a person who claimed to be able to induce OBEs at will, while awake, attempted during randomly selected experimental periods to go to a specified distant location during an OBE and influence a variety of detectors located there, including other persons, animals, and physical detectors of various sorts (R. L. Morris, Harary, Janis, Hartwell, & Roll, 1978). Although the overall psi results of the study were insignificant, there was one intriguing series of trials in which the subject’s new pet kitten showed significantly less movement and less vocalizing during the OBE periods than during the control periods. Examination of physiological data showed that this subject’s OBEs were also accompanied by a fairly distinctive state, consisting of deep relaxation (as evidenced by significant decline of skin potential) coupled with elements of arousal (as evidenced by significant increases of heart rate and respiration rate). There was also a large percentage decline in eye movements, although this was not statistically significant. There were no significant EEG findings.
Osis and McCormick (1980), working with another person who claimed to induce OBEs at will, conducted an experiment in which the task was to view a target in a specially constructed optical image device in which the target appears as an illusion and is visible only from a position directly in front of the viewing window. A random number generator created the target for each OBE trial by making a random composite of three features (independently drawn from four possible background colors, four quadrants, and five line drawings). In addition, unbeknownst to the subject, a strain gauge sensor was situated in a shielded chamber directly in front of the viewing window. Out of 197 such trials, there were 114 hits (a hit being defined as accurate identification of any of the three target features), which was marginally significant. Perhaps more interestingly, strain gauge activation was significantly higher during hits than during misses, both before and after target generation. Although, once again, the results can be interpreted as a combination of clairvoyance and psychokinesis, they are also in line with an hypothesis that is consistent with the subject’s reported experience, namely, that he had projected his consciousness into the viewing chamber at the only point from which the target could be (optically) seen and where the strain gauge was located.
Clearly, these few existing experiments are inadequate to validate any interpretation of OBEs as involving either psi or an “exteriorization” of the mind from the body. Nevertheless, they also collectively demonstrate that further experimental work along these lines is feasible and potentially productive. As with NDEs, the further study of OBEs under appropriate conditions of experimental control and physiological monitoring is urgently needed. We repeat, however, our belief that advances in our understanding of NDEs, OBEs, and related phenomena are likely to come only by moving beyond the current polarization between exclusively psychophysiological models on the one hand and transcendent or “exteriorization” models on the other. OBEs, NDEs, and other such phenomena surely do not occur at random. It is reasonable to suppose that there are physiological and psychological conditions specially conducive to such experiences, and some of the psychological and physiological models proposed, sparse and conjectural as they presently are, may be converging upon some of those conditions. On the other hand, there is also a not insignificant body of evidence supporting the idea that some experiences are more than mere subjective illusions, and this body of evidence cannot simply be “quietly dropped,” as Blackmore would have us do, simply because it presents problems for current models of mind and brain.
In attempting to account for reciprocal apparitions, such as those mentioned above, and for apparitions perceived simultaneously by more than one person (discussed later in this chapter), Myers (1886b) had tentatively proposed the idea that some aspect of consciousness is able in some sense to “go out” from the body and somehow produce an effect in external physical space, not in a conventional material way perceptible to ordinary senses, but nonetheless in a manner sufficient to stimulate an apparition or (as in the case of the strain gauge in Osis and McCormick’s experiment or the kitten in the R. L. Morris et al. study) to affect something physical in the environment.29 Such an idea supposes, as Myers (1886c) did, that the ordinary distinction between mind and matter may not be so straightforward as we often assume, and thus that there may be something intermediate between matter as we ordinarily perceive it and mind as we ordinarily experience it (pp. 178–179; see also our Chapter 2). We might further conjecture that under appropriate psychophysiological conditions, a wide range of experiences may emerge in which the ordinary relationship between consciousness and the body is altered, including some in which consciousness actually does separate from the body.
The neurological condition known as autoscopy bears some phenomenological resemblance to OBEs. Autoscopy has sometimes been defined as “the hallucinatory projection of the body image into perceptual space” (Lukianowicz, 1958, p. 214). This definition, however, is ambiguous as to the subjective point of view from which the experience occurs, leading some authors inappropriately to equate OBEs and autoscopic experiences (e.g., Lunn, 1970). A more precise definition is “a visual experience where the subject sees an image of him/herself in external space, viewed from within his/ her own physical body” (Dening & Berrios, 1994, p. 808). That is, unlike OBEs, in which one’s consciousness itself seems to be located outside the body, and one views the actual physical body from that external position, in an autoscopic experience one’s consciousness seems to remain inside the body, as usual, and it is instead the hallucinatory image or “double” that seems external.30 The autoscopic experience also differs from most spontaneously occurring OBEs, and especially from NDEs, in that it is frequently accompanied by unpleasant feelings of unreality, confusion, or depersonalization (Lukianowicz, 1958). Moreover, autoscopic experiences, as well as OBEs reported by seizure patients, usually involve “fear,” “horror,” “terror,” or some other negative affect (Blanke et al., 2004; Dening & Berrios, 1994; Devinsky et al., 1989). Finally, people experiencing autoscopic hallucinations usually have some identified concurrent neurological or psychological pathology (e.g., Blanke et al., 2004; Damas Mora, Jenner, & Eacott, 1980; Devinsky et al., 1989; Lhermitte, 1951; Lukianowicz, 1958).31 Nevertheless, although OBEs and autoscopic experiences are experientially different in many ways, both phenomena do involve profound alterations in the ordinary relationship between one’s sense of self and sense of the body, and they may involve similar or overlapping mechanisms.
Another phenomenon suggesting an alteration in the ordinary relationship of consciousness and the brain is that of lucid dreams. In dreams of this type the state of consciousness associated with ordinary dreaming is enhanced, in that dreamers become self-conscious, are aware that they are dreaming, and are “fully in possession of their cognitive faculties while dreaming” such that they can initiate purposive behavior (LaBerge & Gackenbach, 2000, p. 152). In a real sense, therefore, the dreamer becomes more “awake” or conscious than is ordinary in sleep and dreams. As we mentioned in Chapter 2, Myers (1887a) had recognized the importance of this particular example of enhanced awareness, saying that
we neglect precious occasions of experiment for want of a little resolute direction of the will….[W]e ought to accustom ourselves to look on each dream, not only as a psychological observation, but as an observation which may be transformed into an experiment…to carry into our dreams enough of our waking self to tell us that they are dreams, and to prompt us to psychological inquiry, (p. 241)32
Like NDEs, lucid dreams were at first widely dismissed as impossible, and it was not until methods were found for objectively demonstrating the occurrence of such dreams that psychologists and sleep researchers accepted the phenomenon (LaBerge & Gackenbach, 2000, pp. 157–158).33 Also, however, as with NDEs, an adequate understanding of lucid dreams will require situating them within a larger group of phenomena involving altered or enhanced mental functioning. For example, one interesting finding of recent OBE research is that people who experience OBEs are likely also to have had lucid dreams, and vice versa (Alvarado, 2000, p. 195). Lucid dreams may be a kind of precursor to simple OBEs or even to more complex, veridical ones. Several people who have frequently experienced or deliberately induced OBEs have suggested using lucid dreaming as a means of inducing OBEs (e.g., J. L. Mitchell, 1981; Muldoon & Carrington, 1929/1973, pp. 125–127; Whiteman, 1956). The two phenomena may well depend upon similar or overlapping physiological mechanisms, and research and theorizing in both areas will likely progress by joining forces.
We turn now to experiences in which a person has seen, heard, or otherwise sensed the presence of a dying or deceased person not physically present. Hallucinations are often defined (and often with pejorative intent) as sensory perceptions in the absence of any corresponding sensory input. By this general definition, many features of NDEs, such as seeing deceased people, a brilliant light, or “other realms,” are hallucinations. The literature on hallucinations is vast, and the circumstances under which they occur are enormously varied (see, e.g., Bentall, 2000; Siegel & West, 1975). Hallucinations are reported, for example, in connection with a wide variety of psychotropic drugs or in alcohol- or disease-induced delirium; both positive and negative hallucinations34 can be produced by hypnosis; they sometimes occur spontaneously in the drowsy states occurring just before sleep or just before awakening (hypnagogic or hypnopompic states); they are related to such phenomena as eidetic imagery, synesthesia, and imaginary playmates; they commonly occur in medical conditions such as migraine (Sacks, 1999) and Charles Bonnet syndrome (Schultz, Needham, Taylor, Shindell, & Melzack, 1996); and they can occur (especially in auditory form) in connection with psychiatric illnesses such as schizophrenia. Because the literature on such experiences is so enormous, we can here only call attention to the absolute necessity of situating NDEs, OBEs, and other such phenomena within this broader context.
One important caveat must be kept in mind here, however, and that is the converse need for the study of hallucinations in general to include, and be informed by, study of the kinds of experiences emphasized in this chapter—that is, NDEs, OBEs, and hallucinations experienced by healthy, sane people in a waking state. A recent review of research on hallucinatory experiences is unfortunately not unique in focusing almost exclusively on psychiatric patients experiencing auditory hallucinations (Bentall, 2000). We have already discussed in Chapter 2 the central place that the study of hallucinatory phenomena held in Myers’s empirical and theoretical work, particularly the investigations and surveys by Myers and his colleagues of spontaneous cases of apparitions of dying or deceased persons (Gurney et al., 1886; H. Sidgwick et al., 1894). These studies, and ones reported in more recent years (e.g., Dale, White, & Murphy, 1962; Green, 1960; W. F. Prince, 1931; Rhine, 1981; Tien, 1991; D. J. West, 1948, 1990), call into serious question the long-prevailing assumption, which we mentioned at the beginning of this chapter, that hallucinations are exclusively pathological in origin, whether physiologically or psychologically generated. Even hallucinations among bereaved persons (e.g., Barbato, 1999; Grimby, 1993; Marris, 1958, p. 15; Olson, Suddeth, Peterson, & Egelhoff, 1985; Rees, 1971), although occurring in conditions of obvious psychological distress, are not considered necessarily pathological in the current edition of the Diagnostic and Statistical Manual of Mental Disorders (1994). Clearly, no theory of hallucinations can be adequate unless it takes into account the wide variety of conditions, physiological and psychological, under which they occur, including—importantly—apparitions reported by sane, awake, healthy individuals.
Additionally, just as an adequate theory of NDEs or OBEs must take into account the veridical perceptions sometimes occurring outside the person’s ordinary sensory capacities, an adequate theory of hallucinatory experience must take into account reports of veridical apparitions. Particularly important examples of these are cases in which the hallucination coincided closely in time with the death or some other crisis happening to the person seen or heard in the hallucination, even though the percipient did not yet know about that death or crisis. Such cases are far from infrequent. It is no exaggeration to say that thousands of them have been investigated and reported, primarily in the pages of the Proceedings and Journals of the Society for Psychical Research and of the American Society for Psychical Research (see, e.g., Gurney et al., 1886; E. M. Sidgwick, 1922; H. Sidgwick et al., 1894). Relatively few cases have been reported in more recent decades, but this is almost certainly the result of the sharp decline of interest among experimentally oriented parapsychologists in the investigation of spontaneous experiences, rather than of any falling off in their actual rates of occurrence. Stevenson (1995) reported three such “crisis” cases, and in a recent study by one of us (EWK), at least 18 such apparitions were reported.35 In addition to the sheer quantity of such cases, the quality of the evidence is such that they cannot be dismissed en masse as unsubstantiated “anecdotes.” Hart et al. (1956), for example, analyzed a collection of 165 previously published cases in which one of the criteria for inclusion was a written or oral report made of the experience, or action taken because of the experience, before the corresponding event was learned about normally.
Another important group of cases suggesting that not all hallucinations are purely subjective is that of “collective” cases, in which more than one person has simultaneously seen the apparition. In one case (which provides an example both of collective perception and of the crisis apparitions mentioned above), a man and his 5-year-old son simultaneously saw at the ceiling the face of the man’s father, at the time (they subsequently learned) that this person had died. The man’s wife, who was sitting in the same room, corroborated having witnessed the reactions and comments of her husband and son, although she did not herself see the apparition (Gurney et al., 1886, vol. 2, pp. 248–250). Such cases are again not infrequent: Tyrrell (1943/1953) reported that he had found 130 collective cases in the literature and had “no doubt that this list is not exhaustive” (p. 69). Furthermore, although collective cases are a small fraction of all reported apparitions, most witnesses report being alone at the time they saw the apparition—a condition perhaps conducive to such an experience. But among cases in which more than one person was present, a third (H. Sidgwick et al., 1894, pp. 320–321; Tyrrell, 1943/1953, p. 23) to half (H. Hart et al., 1956, pp. 204–205) involved collective perception, although, as we saw in the case described above, not everyone present necessarily shares the experience.
Other features of collective cases likewise suggest that they are something more than subjective experiences. As Tyrrell pointed out (1943/1953), the testimony in collective cases indicates that “all the percipients see the same thing, each from his own point of view in space, just as though it were a material figure” (p. 70). In support of this observation, Tyrrell listed 19 features (of both solitary and collective cases) that suggest some kind of objectivity to the figure seen (pp. 77–80). For example, in one case a man reported seeing in his bedroom the figure of his brother on the night the brother was killed, and he continued to see the figure, in the same spot but from different perspectives, even when he walked around and away from it (Gurney et al., 1886, vol. 1, pp. 556–559). In another case, a woman saw an apparition of a dying friend reflected in a mirror, as well as when she turned to look directly at it (Myers, 1895e, pp. 444–446; also in HP, vol. 1, pp. 421—423). In still other cases, the apparition may obscure light and cast a shadow (e.g., Myers, 1889d, p. 28; this case, incidentally, was also a collective case).
It was collective cases specifically that led to the two major ways of interpreting apparitions in general. On the one hand, Gurney had argued that veridical, or “crisis,” apparitions occur when the person learns tele-pathically36 about, say, the death of the distant person; this information then emerges into consciousness in the form of an hallucination. Collective cases occur when one primary percipient receives the information telepathically and then “spreads” the information, also telepathically, to other persons present who are sufficiently sensitive to detect it. In contrast, Myers believed that the existence of so many cases in which multiple percipients had perceived the apparition in consistent fashion, together with certain details suggesting some kind of objectivity (such as those described in the previous paragraph), supported the idea that at least some apparitions have a more objective character than telepathic impression alone can account for. He thus proposed his idea of “phantasmogenetic efficacy,” which we briefly described earlier in this chapter, in which apparitions are in some sense spatial, or affect space, without being physical in any ordinary sense.37
As we also mentioned earlier, one important feature of NDEs is that of perceiving identifiable deceased persons during the experience. Closely related to this feature of NDEs are deathbed visions. Deathbed visions are experiences in which dying people seem to see or converse with people not physically present—usually deceased persons—or to perceive some environment not physically evident to bystanders. Occasionally, a bystander will also perceive what a dying person seems to be seeing (see, e.g., Howarth & Kellehear, 2001; Stevenson, 1995, pp. 359–361).
Like NDE experiencers, dying persons who see people not physically present almost invariably see deceased persons, not living ones. Deathbed visions rarely seem to involve other features prominently associated with NDEs, such as OBEs or tunnels, but these differences may be more apparent than real because an even more fundamental difference between NDEs and deathbed visions is that in the latter the experiencer usually dies shortly after the experience. We therefore rarely get direct accounts from dying persons themselves; reports of what they experienced come rather from people at their bedside who heard what the dying person said about the experience or who witnessed behavior suggesting what the dying person was experiencing. As a result, we probably know little about the full extent and character of the dying person’s experience. Nevertheless, the similarities between NDEs and deathbed visions suggest that, just as NDEs overlap in certain respects with OBEs, so also do they overlap, in different ways, with deathbed visions. It seems likely that all are variants of some larger class of phenomena whose nature has yet to be adequately delineated.
There has been little systematic research to date on deathbed visions. Collections of cases have been published (e.g., W. F. Barrett, 1926; Bozzano, 1906), but in modern times only Osis (1961) and Osis and Haraldsson (1977/1997) have attempted a systematic survey of such experiences. Because these surveys were based entirely on the retrospective recollections of doctors and nurses, often from many years earlier, the findings must be considered preliminary only, and they tell us little about the real incidence and character of such experiences. Nevertheless, they provide reason to believe that deathbed visions may be far more common than is presently recognized, and potentially accessible to more systematic study. Our own informal inquiries, particularly with hospice doctors and nurses, have strongly suggested that such experiences are in fact quite frequent. Moreover, in a recent study conducted by one of us (EWK), the single most common experience reported was being with a dying person who seemed to see or hear deceased loved ones; 218 out of 525 respondents reported such an experience, including 36 nurses or other hospital workers who reported witnessing such experiences, some of them on multiple occasions. Clearly, systematic research is needed to learn more about the incidence, nature, and circumstances of these theoretically important and humanly meaningful experiences.
Sufficient evidence is already available, however, to counter any facile blanket dismissal of deathbed visions as mere hallucinations of a dying brain. We need to keep in mind, first, that deathbed visions are not isolated phenomena. As we have seen, people also report seeing deceased persons in various conditions other than that of actually dying—for example in NDEs in which they were not physiologically close to death, or in apparitions experienced by awake, healthy persons. Second, Osis and Haraldsson (1977/1997) reported that patients were actually less likely, not more likely, to have deathbed visions if they were on medications or had illnesses affecting consciousness. Also, there are again cases that call into question even more directly this explanation of deathbed visions as subjective hallucinations. For example, in so-called “Peak in Darien” cases, the dying person apparently sees, and often expresses surprise at seeing, a person whom he or she thought was living, but who had in fact recently died. Reports of such cases are scattered and often not adequately documented; but there are enough of them to warrant giving them serious attention.38
An even rarer kind of deathbed experience, but one that like NDEs calls into question the absolute dependence of mental functioning on the state of the brain, are cases in which the dying person has demonstrated a sudden revival in mental functioning just before death. People sometimes appear to revive somewhat physically just before death. In a case in our collection, a woman, dying of congestive heart failure, was on oxygen, in a coma, and unable to communicate. At one point, however, according to her daughter, who was present, “much to my surprise she not only sat up in bed but leaped over the bottom rail of the bed, saying ‘Jim [her deceased brother], wait for me, don’t go….’ She was looking at the wall behind where I sat and obviously saw something I did not.” Her daughter and the nurses present had trouble restraining her. She did not die on this occasion, but did so a month later, after being sent home since her condition seemed to have improved.
Even more interesting than these physical revivals, however, are revivals in mental functioning. Myers (1892b) had referred to the “sudden revivals of memory or faculty in dying persons” (p. 316), and there are scattered reports of people apparently recovering from dementia shortly before death. The eminent physician Benjamin Rush, author of the first American treatise on mental illness (1812), observed that “most of mad people discover a greater or less degree of reason in the last days or hours of their lives” (p. 257). Similarly, in his classic study of hallucinations, Brierre de Boismont (1859) noted that “at the approach of death we observe that… the intellect, which may have been obscured or extinguished during many years, is again restored in all its integrity” (p. 236). Flournoy (1903, p. 48) mentioned that French psychiatrists had recently published cases of mentally ill persons who showed sudden improvement in their condition shortly before death.
In more recent years, Osis (1961) reported two cases, “one of severe schizophrenia and one of senility, [in which] the patients regained normal mentality shortly before death” (p. 24). Osis and Haraldsson (1977/1997) reported a case of a meningitis patient who had been “severely disoriented almost to the end,” but who “cleared up, answered questions, smiled, was slightly elated and just a few minutes before death, came to herself” (p. 133). Turetskaia and Romanenko (1975) reported three cases involving remission of symptoms in dying schizophrenic patients. Grosso (2004, pp. 42–43) described three dementia cases that had been reported to him, one by a colleague and two by a nurse. In all three cases, the patient had not recognized family members for several years, but shortly before death they all were said to have become more coherent or alert and to have recognized family members. Such cases are few in number and not adequately documented, but the persistence of such reports suggests that they may represent a real phenomenon that could potentially be substantiated by further investigations. If so, they would seriously undermine the assumption that in such diseases as Alzheimer’s the mind itself is destroyed in lockstep with the brain (e.g., Edwards, 1997, pp. 295–296). Like many of the experiences discussed in this chapter, such cases would suggest that in some conditions, consciousness may be enhanced, not destroyed, when constraints normally supplied by the brain are sufficiently loosened.
NDEs also have ties to still another class of phenomena that must be considered when evaluating proposed explanations. Many features of NDEs are similar to those of mystical experiences. The ineffability of the experience and the sense of being in the presence of something larger than or transcendent to oneself are features common to both NDEs and mystical experiences. Just as with NDEs, the onset of a mystical experience is often accompanied by overwhelming feelings of joy, happiness, and peace (James, 1902/1958, pp. 157, 204–205). People sometimes describe a feeling of sudden release, and although they usually seem to mean this figuratively, some reports border on an OBE: As one of Leuba’s subjects said, “I cannot tell you whether I was in the body or out of the body” (Leuba, 1896, p. 372).39
As with NDEs, many mystical experiences involve enhanced mental functioning or heightened perception. Sometimes the “senses are much more acute,” such that details of the experience and of one’s physical surroundings at the time “are frequently recalled with great minuteness” (Star-buck, 1906, p. 78). One of James’s (1902/1958) experiencers said that “my memory became exceedingly clear” (p. 157). A sensory phenomenon that is particularly common in mystical experiences, as well as NDEs, is the sense of seeing a bright light of unusual quality, such as “a strange light which seemed to light up the whole room (for it was dark)” (p. 202). Some people seem to be using the phrase “seeing the light” in a figurative sense, but others are clearly referring to what was to them a real and vivid sensory phenomenon.
We will discuss mystical experiences in detail in Chapter 8, but here we focus on one further and extremely significant feature common to both classes of experience—namely, the transformative aspect, especially of experiences sometimes called conversion experiences. Whatever the explanation of NDEs may be, there is no doubt that they have a profound and apparently lasting impact on many people who experience them. As we noted earlier, they often precipitate a significant change in values, attitude toward death, and a new sense of purpose or meaning in life. Similarly, conversion experiences are, by definition, sudden and lasting changes in character and values such that “religious ideas, previously peripheral in… consciousness, now take central place” (James, 1902/1958, p. 162). Conversion experiences bring a “changed attitude toward life” (Starbuck, 1906, p. 360), including changes in the person’s relationship with God, perception and appreciation of nature, attitude toward self, and, perhaps most significantly, attitude toward other people (“I was very selfish… now I desired the welfare of all mankind” [James, 1902/1958, p. 157]).
As we seek to evaluate various theories of NDEs, it is important to emphasize that this transformative aspect is never, so far as we have been able to discover, reported in connection with the various fragmentary experiences sometimes glibly equated with NDEs, such as the “dreamlets” of acceleration-induced hypoxia, experiences associated with other abnormalities of blood-gas concentrations, or experiences reported by patients receiving temporal lobe stimulation.40 Moreover, the transformative features associated with NDEs differ from those associated with simply coming close to death but without having an NDE (Greyson, 1983a; Ring, 1984; van Lommel et al., 2001). Clearly, the profound transformative aspect of NDEs suggests that we need some explanation that goes beyond the physiological models we have so far, and even beyond the psychological experience associated with coming near death.
Many conversion experiences are said to have been preceded by a period of intense brooding, depression, and questioning, and they seem to be the result, not so much of conscious striving, but of subliminal “incubation” of these problems and thoughts, followed by a sudden intrusive experience of unexpected character that leads to a profound shift in the person’s perspective and attitude (James, 1902/1958). Conversion experiences, therefore, like NDEs, mystical or religious experiences in general, and creativity and genius, may be best understood with reference to Myers’s view of a larger and active subliminal consciousness from which there is occasionally an “uprush” of material into ordinary waking consciousness. Moreover, this “uprush”—and hence these experiences—may all occur more readily in people in whom the “barrier” between supraliminal and subliminal regions of the mind is, as Myers put it, more “permeable,” whether constitutionally or because it has been weakened by certain psychological or physiological conditions.41
Some of the literature on religious conversion experiences has followed the well-worn pathway (discussed in Chapters 7 and 8) found in the literature on mysticism and on genius by emphasizing pathological manifestations. Dewhurst and Beard (1970), for example, reviewed some of the literature on religiosity, conversion, and religious hallucinations among epileptics, including a review of evidence suggesting that many Christian mystics were in fact epileptics, and they then described six of their own epileptic patients with “mystical delusional experiences.” Again, however, a more balanced picture of all these phenomena may emerge if we keep in mind Myers’s argument, discussed in Chapter 2, that the psychological mechanism of a “permeable barrier” can lead to evolutive as well as dissolutive phenomena, from undeniably dysfunctional pathology to the highest levels of creative and religious experience.
Thus far in this chapter, we have concentrated on outlining a variety of interrelated phenomena and some of the theories that have been proposed to account for them. A major insight that emerges from such a review is the general recognition that similar experiences can occur under widely varying psychological and physiological conditions. A major problem remains, however: Why do most people, when subjected to the same or similar conditions, not have such experiences, whether NDEs, OBEs, apparitions, or any of the other experiences discussed in this chapter? For example, most people who suffer cardiac arrest do not report NDEs: Only 12% of the cardiac arrest patients in van Lommel et al.’s (2001) study, 10% in Greyson’s (2003) study, and 6.3% in Parnia et al.’s (2001) study did so.42
Part of the answer undoubtedly has to do with the fact, pointed out earlier in this chapter, that many people who have unusual experiences such as NDEs are reluctant to talk about them, not only with medical personnel but even with their friends and families, including even spouses. Additionally, in some cardiac arrest patients, persisting physiological consequences of the arrest and resuscitation may have blocked memory for any experience. Van Lommel et al. (2001), for example, noted that generalized memory defects were significantly more frequent (14%) among those who did not report an NDE than among those who did (2%). But this still leaves a large reservoir of patients who apparently had no such experience. What might distinguish these patients from those who did?
Van Lommel et al. (2001) provide some intriguing clues on the physiological side. There were no significant differences in terms of the resuscitation procedures themselves—that is, factors such as the use of medications, intubation, and defibrillation. The groups also did not differ significantly in terms of other measures of proximity to death, such as the duration of arrest and unconsciousness. Both groups included patients who had cardiac arrest out of the hospital, making a precise evaluation of their actual physiological condition somewhat more difficult. Nonetheless, patients who reported an NDE were more than twice as likely to die within 30 days than those who did not. Clearly, one high priority for further research will be to characterize more precisely the relationship between actual physiological proximity to death, the likelihood of experiencing an NDE, and the phenomenological character of the experiences that do occur.
More generally, however, the occurrence of not only NDEs but also other related experiences under such a wide variety of physiological conditions, and to only some people, suggests the need to expand the search for an adequate theoretical model which includes psychological factors. General support for this idea might come from the additional finding of van Lommel et al. (2001) that reporters of NDEs were more than three times as likely as non-reporters to have had a previous NDE, even though the reporters as a group were significantly younger than the non-reporters. This suggests again that future research might profit in particular by examining all the experiences discussed in this chapter in light of Myers’s model of a “permeable barrier” that controls the exchange of material between supraliminal and subliminal levels of consciousness. On this model, some people have more chronically permeable barriers than others, and in all of us the permeability can vary with changes in physiological or psychological conditions.43 The model predicts, therefore, that people reporting NDEs, as well as other related experiences, differ from other people on measures of hyp-notizability, absorption, schizotypy, dissociation, or transliminality. As we mentioned earlier, a few studies have already found some differences in dissociative tendencies, absorption, and fantasy proneness between those who have had an NDE and control groups consisting of otherwise unselected persons who have not. A more meaningful comparison, however, might be between NDE experiencers and a control group of people who have been in the same or similar physiological circumstances but did not have an NDE.
This model might also help make sense of what is currently a “loose end” in the literature on awareness during general anesthesia. We mentioned earlier that the evidence for memory of events occurring while a patient was adequately anesthetized is generally poor. Interestingly, however, the most impressive reports of explicit (or conscious) awareness of events during anesthesia have been elicited by hypnosis (Cheek, 1964, 1966; Levinson, 1965). The historically important Levinson study, for example, involved 10 highly hypnotizable subjects undergoing very similar surgical procedures carried out under a deliberately deep and uniform anesthesia regime monitored with EEG. A month later—but only under hypnosis—four of these patients recalled nearly verbatim, and four others recalled partially, standardized remarks made by the anesthetist in conjunction with a staged “crisis” in the procedure. These studies have never, to our knowledge, been adequately followed up, but they should be, because such results, if replicable, suggest, like NDEs, that mind is still somehow able to operate when the brain is disabled by anesthesia. Moreover, they suggest, as Myers argued, that hypnosis is a method particularly conducive to loosening the “barrier” and thus accessing subliminal levels of consciousness.
Following Myers, we have argued that explanatory models for the phenomena we have discussed in this chapter must take into account not only the full range of features and conditions associated with each individual phenomenon in isolation, but also the wide variety of related phenomena that share some of its principal features. We are not suggesting simplistically that all these phenomena will one day be brought under the rubric of one all-encompassing explanation. Nonetheless, we are arguing that if we are to understand any particular phenomenon, we must situate it in the context of related phenomena, an exercise that may then ultimately lead to a greatly expanded view of the nature of all of them. As noted several times in this chapter, the phenomena that we have discussed all suggest a marked alteration, not only in the person’s state of consciousness, but more broadly in the ordinary relationship of the person’s consciousness with the external world. We emphasize again that some of these alterations—sharing common characteristics despite the apparent diversity of means by which they may be brought about—suggest that there may be more to the external environment itself than our ordinary sensorimotor functioning can detect.
The challenge of NDEs in particular, however, goes beyond situating them properly within a broader framework of cognate phenomena. The challenge lies also in recognizing and accounting for one central feature that in our opinion makes this phenomenon uniquely important in any contemporary discussion of the mind-brain problem—specifically, the occurrence of vivid and complex mentation, sensation, and memory under conditions in which current neuroscientific models of the mind deem conscious experience of any significant sort impossible. The stark incompatibility of NDEs with current models of mind-brain relations is particularly evident in connection with experiences that occur under two conditions—general anesthesia and cardiac arrest. We wish now to highlight this conflict, because the theoretical significance of the many experiences occurring under these conditions has perhaps not been sufficiently appreciated. In both of these situations, we will argue, much more is at issue than some vague sense of incompatibility between the characteristics of the mentation that occurs and the physiological conditions under which it occurs.
In Chapter 1 we noted that the current mainstream doctrine of biological naturalism has coalesced neuroscientifically around the family of “global workspace” theories. Despite differences of detail and interpretation, all of these theories have in common the view that the essential substrate for conscious experience—the neuroelectric activities that make it possible and that constitute or directly reflect the necessary and sufficient conditions for its occurrence—consist of synchronous or at least coherent high-frequency (gamma-band, roughly 30–70 Hz) EEG oscillations linking widely separated, computationally specialized, regions of the brain.44 An enormous amount of empirical evidence supports the existence of these mind-brain correlations under normal conditions of mental life, and we do not dispute this evidence. The conventional theoretical interpretation of this correlation, however—that the observed neuroelectric activity itself generates or constitutes the conscious experience—must be incorrect, because in both general anesthesia and cardiac arrest, the specific neuroelectric conditions that are held to be necessary and sufficient for conscious experience are abolished—and yet vivid, even heightened, awareness, thinking, and memory formation can still occur.45
Take first the case of NDEs occurring under conditions of general anesthesia: In our collection at the University of Virginia, 23% of the computer-coded cases occurred under anesthesia, and these involved the same features that characterize other NDEs, such as having an OBE and watching medical personnel working on their body, an unusually bright or vivid light, meeting deceased persons, and—significantly—thoughts, memories, and sensations that were as clear or clearer than usual. If the incidence of cases involving anesthesia in our collection is any indication of the general incidence, then conservatively many thousands of NDEs have occurred during surgical procedures involving general anesthesia.
John et al. (2001) recently carried out a massive study intended specifically to identify reliable EEG correlates of loss and recovery of consciousness during general anesthesia. They analyzed 19-channel recordings obtained from 176 surgical patients, using three common types of anesthesia regime involving diverse mechanisms of action, and they sought to characterize common properties of the EEG patterns associated with the main stages of anesthesia. Their results first confirmed and extended what has long been the main story about anesthesia and EEG, namely, that unconsciousness is associated with a pronounced shift toward lower frequencies in the delta and low theta range, with a more frontal distribution and higher power. More significantly, they showed that gamma-type EEG rhythms lost power and became decoupled across the brain when patients lost consciousness, and that these changes were reversed with return of consciousness. The whole pattern, as Baars points out in a commentary on the paper (Baars, 2001), is consistent with current neurophysiological theories of the global workspace, and appears to reflect its complete disabling under conditions of adequate anesthesia.
Additional results supportive of this conclusion derive from other recent functional imaging studies that have looked at blood flow, glucose metabolism, and other indicators of cerebral activity under conditions of general anesthesia with agents including propofol, halothane, isoflurane, and deep sedation with benzodiazapines such as midazolam (Alkire, 1998; Alkire, Haier, & Fallon, 2000; Fiset et al., 1999; Shulman, Hyder, & Rothman, 2003; Veselis et al., 1997; and N. S. White & Alkire, 2003), as well as related conditions such as persistent vegetative states and coma (see Laureys et al., 2004, and the numerous references cited there). In these studies, brain areas essential to the global workspace are consistently deactivated individually and decoupled functionally in surgically adequate anesthesia and related states of unconsciousness. Auditory and other stimuli are still able to activate their primary receiving areas in the cortex, since the sensory pathways remain relatively unimpaired, but these stimuli are no longer able to ignite the large-scale cooperative network interactions that normally accompany conscious experience.
The situation is even more dramatic with regard to NDEs occurring during cardiac arrest, many of which in fact occur also in conjunction with major surgical procedures involving general anesthesia. As mentioned earlier, there have been numerous reports of NDEs in connection with cardiac arrest, and, like those that occur with general anesthesia, they include the typical features associated with NDEs, most notably vivid or even enhanced sensation and mentation. A typical case is that reported by MacMillan and Brown (1971) of a cardiac arrest patient who prefaced his description of an OBE and seeing a light by saying: “I do not have words to express how vivid the experience was. The main thing that stands out is the clarity of my thoughts during the episode” (p. 889). Another typical comment was that of a 6-year-old cardiac arrest victim who insisted that “it was realer than real” (M. Morse, 1994a, p. 67).
Cardiac arrest, however, is a physiologically brutal event. Cerebral functioning shuts down within a few seconds. Whether the heart actually stops beating entirely or goes into ventricular fibrillation, the result is essentially instantaneous circulatory arrest, with blood flow and oxygen uptake in the brain plunging swiftly to near-zero levels. EEG signs of cerebral ischemia, typically with global slowing and loss of fast activity, are visually detectable within 6–10 seconds, and progress to isoelectricity (flat-line EEGs) within 10–20 seconds of the onset of arrest. In sum, full arrest leads rapidly to establishment of three major clinical signs of death—absence of cardiac output, absence of respiration, and absence of brainstem reflexes—and provides the best model we have of the dying process (DeVries, Bakker, Visser, Diephuis, & van Huffelen, 1998; Parnia & Fenwick, 2002; van Lommel et al., 2001; Vriens, Bakker, DeVries, Wieneke, & van Huffelen, 1996). Nevertheless, in five published studies alone, over 100 cases of NDEs occurring under conditions of cardiac arrest have been reported (Greyson, 2003; Parnia et al., 2001; Sabom, 1982; Schwaninger et al., 2002; van Lommel et al., 2001), and there are many more in other collections, including our own.
The case of Pam Reynolds, described earlier in this chapter, is a notable example of an NDE that occurred under conditions involving both deep general anesthesia and cardiac arrest of a particularly extreme form. As pointed out in our earlier discussion, we do not know precisely when in the surgical procedure Pam had her experience, other than to say that the early parts of the experience, including the OBE, occurred when she was not yet “brain dead” but already deeply anesthetized. Nonetheless, even if we assume for the sake of discussion that her entire experience occurred during these earlier stages of the procedure, brain activity even at that time was inadequate to support organized mentation, according to current neurophysiological doctrine.
How might scientists intent upon defending the conventional view respond to the challenge presented by cases occurring under conditions like these? First, it will undoubtedly be objected that even in the presence of a flat-lined EEG there still could be undetected brain activity going on. Current scalp-EEG technology detects only activity common to large populations of suitably oriented neurons, mainly in the cerebral cortex; and so perhaps future improvements in technology will allow us to detect additional brain activity not visible to us at present. This objection may seem to have some force, because both experimental and modeling studies show that certain kinds of electrical events in the brain, such as highly localized epileptic spikes, do not appear in scalp recordings (Pacia & Ebersole, 1997). Moreover, recordings carried out under conditions of general anesthesia comparable to those used with Pam Reynolds provide direct evidence that some residual electrical activity can appear subcortically or in the neighborhood of the ventricles, even in combination with an essentially flat scalp EEG (Karasawa et al., 2001).
This first objection, however, completely misses the mark. The issue is not whether there is brain activity of any kind whatsoever, but whether there is brain activity of the specific form regarded by contemporary neuroscience as the necessary condition of conscious experience.46 Activity of this form is eminently detectable by current EEG technology, and as we have already shown, it is abolished both by adequate general anesthesia and by cardiac arrest. In cardiac arrest, even neuronal action-potentials, the ultimate physical basis for any possible coordination of neural activity between widely separated brain regions, are rapidly abolished (van Lommel, 2006). Moreover, cells in the hippocampus, the region thought to be essential for memory formation (see Chapter 4), are known to be especially vulnerable to the effects of anoxia (Vriens et al., 1996). In short, it is not credible to suppose that NDEs occurring under conditions of adequate general anesthesia, let alone cardiac arrest, can be accounted for in terms of some hypothetical residual capacity of the brain to process and store complex information under those conditions.
A somewhat more credible line of defense, perhaps, is to suggest that the experiences do not occur when they appear to occur, during the actual episodes of brain insult, but at a different time, perhaps just before or just after the insult, when the brain is more or less normally functional. After all, we do know that large amounts of vivid experience can occur in just a few seconds, for example in conjunction with the fall of an alpine climber (Heim, 1892/1972). This suggestion too encounters serious problems, however. First, episodes of ordinary unconsciousness produced by physiological events such as ventricular fibrillation or cardiac arrest characteristically leave their subjects amnesic and confusional for events immediately preceding and following these episodes, the more so in proportion to their duration and severity (Aminoff et al., 1988; Parnia & Fenwick, 2002; van Lommel et al., 2001). In addition, the confusional experiences occurring as a person is losing or regaining consciousness never, to our knowledge, have the life-transforming impact so characteristic of NDEs. Second, a substantial number of NDEs, like Pam Reynolds’s, contain apparent time “anchors,” in the form of verifiable reports of events occurring during the period of insult itself. For example, the cardiac-arrest victim described by van Lommel et al. (2001) had been discovered lying in a meadow 30 minutes or more prior to his arrival at the emergency room, comatose and cyanotic, and yet days later, having recovered, he was able to describe accurately various circumstances occurring in conjunction with the ensuing resuscitation procedures in the hospital.
We have observed two kinds of critical responses, totally divergent, to verifiable time-anchor events of this sort. The first, favored by mainstream critics, is essentially to deny that the reported events have occurred or that they have any force. They are mere “anecdotes,” without value as scientific evidence. We will make only two comments regarding this attitude, in relation to the entire body of evidence presently available. First, it is scientifically inappropriate to approach each such “anecdote” in complete isolation, as though it stands on its own as the only evidence in existence for phenomena in which people have obtained information about situations from which they were sensorially isolated. As stated in our Introduction and documented in the Appendix, phenomena of this type are independently known to exist; what is unusual here is only the specific circumstances of their occurrence. Second, as emphasized especially by Bergson (1913) in his Presidential Address to the SPR, many reports of veridical spontaneous experiences (including those associated with NDEs) are not simply vague or general statements but contain very specific details, and the correspondence of these details with remote events must be recognized as highly unlikely to have occurred by chance, even if we cannot compute their improbability with any great exactitude.
The other critical response comes from persons who take the available veridical reports seriously, like ourselves, but interpret them differently. Their suggestion, essentially, is that the NDE is simply an imaginative reconstruction, and one which can sometimes incorporate paranormally derived information, obtained when the brain is fully functional, about events occurring during the period of unconsciousness. We will again make just two brief comments in response: First, this form of counter-explanation will presumably provide little solace to mainstream critics, since it incorporates as an essential ingredient psi processes which are themselves equally inconsistent with current mainstream views. Second, although this time-displaced psi interpretation, like other “super-psi” hypotheses, cannot be decisively refuted, it simply ignores, in our opinion, the essential core of NDE phenomenology—that these intense and vivid experiences are subjectively timed to the moment of the reported and verifiable events and are remembered that way for years or decades afterwards. It would also need to explain why the reports always follow, never precede, the events in question, and why their subjects characteristically show little or no evidence of psi capacities in any other context before the NDE.
Two further critical responses merit only still briefer mention. One is to suggest that these supposedly verifiable NDEs are being inadvertently misreported, whether by the subjects of the experiences themselves or by their investigators. That is certainly always a possibility to be guarded against in individual cases; but when this suggestion is used repeatedly and without supporting evidence as a blanket defense against the entire body of evidence, it should be recognized for what it is, which is simply an unwillingness to examine that evidence in a truly scientific spirit. The same response applies, but even more so, to any suggestion that the investigators of NDEs are just making it all up. As the philosopher Henry Sidgwick (1882) pointed out in his initial Presidential Address to the SPR in 1882: “We have done all that we can when the critic has nothing left to allege except that the investigator is in the trick. But when he has nothing else left to allege he will allege that” (p. 12).
In sum, the central challenge of NDEs lies in asking how these complex states of consciousness, including vivid mentation, sensory perception, and memory, can occur under conditions in which current neurophysiological models of the production of mind by brain deem such states impossible. This conflict between current neuroscientific orthodoxy and the occurrence of NDEs under conditions of general anesthesia and/or cardiac arrest is head-on, profound, and inescapable. In our opinion, no future scientific or philosophic discussion of the mind-brain problem can be fully responsible, intellectually, without taking these challenging data into account. We refer readers back to the quotation from Myers with which we began this chapter, and to the challenge that he issued over a century ago. Only when researchers approach the study of NDEs and their associated physiological conditions with this question firmly in mind will we progress in our understanding of NDEs beyond the sorts of ill-founded neuroscientific and psychological speculations that abound in the contemporary literature. Similarly, however, only when neuroscientists and psychologists examine current models of mind in light of NDEs and related phenomena such as those discussed in this chapter will we progress in our understanding of consciousness and its relation to brain.
1. We wish to emphasize immediately that our use of the word “hallucination,” here or elsewhere, is in no way meant to imply that the experiences we discuss in this chapter are pathological. We define “hallucination” as a perceptual experience in the absence of corresponding sensory input. Following Myers’s approach, we propose that the word “hallucination” should be understood more broadly as a psychological process that can take non-pathological as well as pathological forms, depending on the circumstances in which the experiences occur. Unfortunately, the association of the word “hallucination” with pathology and delusion is so ingrained that Stevenson (1983b) has suggested that we need a new word, “idiophany,” to refer to non-pathological hallucinations. Until this is or some other word becomes widely adopted, however, we will continue to use the word “hallucination” to include the large number of experiences that go beyond sensory perception but that seem to have more in common with ordinary sensory experiences than with illusions or delusions.
2. See, for example, Audette (1982), C. B. Becker (1981, 1984), C. Carr (1993), Counts (1983), Feng and Liu (1992), R. Gardner (1983, p. 1932), Holck (1978), Kellehear (1993), Lundahl (1982), Osis and Haraldsson (1977/1997), Pasricha (1993), Pasricha and Stevenson (1986), Schorer (1985), and Zaleski (1987).
3. In our studies patients are judged to be near death if the medical records indicated a loss of some vital sign such as blood pressure or pulse or if the condition was serious enough to have caused death if the patient had received no medical attention. Patients judged not to be near death were those whose medical records indicated that they had a serious, but not life-threatening condition and those who were not seriously ill. Many of these medical records were obtained years after the experience in question, and we cannot vouch for their accuracy or completeness. Nevertheless, as a group they illustrate the wide variety of physiological conditions in which these experiences can occur.
4. Unpleasant experiences seem to be the exception, however. In our collection, for example, among cases for which we have data on this feature, only 11% described the NDE as being either “totally unpleasant” or “mostly unpleasant.”
5. See, for example, Bauer (1985), Flynn (1986), Grey (1985), Greyson (1983a, 1992), Noyes (1980), Ring (1980, 1984), Sabom (1982), and van Lommel et al. (2001).
6. In this respect, NDEs are like mystical experiences. There has long been a dichotomy of opinion about mystical experiences, some emphasizing the cross-cultural differences in reports of mystical experience, others (such as James, 1902/1958, and Stace, 1960/1987) arguing that there is a core of common experience behind those differences. We discuss this issue more fully in Chapter 8.
7. We have had people tell us that they had never told anyone about their experience, until they contacted our research unit and told us. While interviewing a woman at her home about her NDE, one of us (EWK) learned that she had never before told her husband about her experience. Moreover, when EWK’s impending visit prompted the woman to explain to her husband the reason for the visit, he told her that he too had had an NDE, which he had never told her about.
This example is not unique. K. Clark (1984) reported a similar situation: At the hospital and in the presence of his wife, a patient told Clark about his NDE, which occurred during multiple episodes of cardiac arrest. When he had finished his description, his wife told them both that she too had had an NDE, during childbirth a few years earlier, but that “she had never told anyone about this, even her husband, because he had ‘always been scientific minded and I just didn’t think he would accept it, and I wasn’t prepared to be rejected’“ (p. 249). Another patient, readmitted to Clark’s unit several years after an earlier hospitalization, told her that, although she had twice asked him during the earlier hospitalization whether he had any unusual memories associated with his accident, “he had lied and denied any recollections… [because] the experience had been so personal that he needed to come to terms with it in his own mind before telling anyone about it” (p. 246).
8. Gabbard and Twemlow (1984) were actually comparing depersonalization with out-of-body experiences (OBEs), not NDEs in particular, but the features they attributed to OBEs (p. 114) apply equally to NDEs. As we will discuss later in this chapter, OBEs and NDEs are overlapping phenomena, although neither can be subsumed under the other.
9. There does seem to be a tendency for NDEs to be reported by younger persons, at least among cardiac patients (see van Lommel et al., 2001, p. 2043); but whether this is because NDEs are more likely to occur in younger people, whether it is because younger people are more likely to report NDEs, or whether older people are less likely to survive a medical condition in which an NDE might occur are questions that remain open.
10. Some authors have reported measurements of arterial blood gases in patients reporting an NDE that do not support the hypothesis of lowered oxygen levels or heightened carbon dioxide levels (M. Morse et al., 1989, p. 50; Parnia et al., 2001; Sabom, 1982, p. 178). Others, however, have questioned the reliability of arterial blood measurements as indicators of what may be going on in the brain (Glicksman & Kellehear, 1990).
11. This feature of sudden cessation of pain, and its return when the NDE ends, strikes us as especially difficult to explain from a conventional neurophysiological point of view.
12. Jansen (1997, p. 8) reports that he has had both types of experience and found them to be similar, but we know of no other such reports.
13. Moreover, as we will discuss later in this chapter, Gloor and his colleagues called into question the assumption that it is the stimulation of the temporal lobes that produces the phenomena reported. Using both surface and depth electrodes, they showed that limbic structures associated with temporal cortex, rather than temporal cortex itself, constituted the anatomical substrate for these effects.
14. It is also important to note that Granqvist et al. (2005; see also Larsson, Larhammar, Frederikson, & Granqvist, 2005) were unable to replicate Persinger’s results. They concluded that, whereas their studies had involved a strict double-blind protocol, Persinger’s participants had been inadequately blinded and therefore that “suggestibility may account for previously reported effects” (Granqvist et al., 2005, p. 1). For another skeptical evaluation of Persinger’s claims—by one who has experienced Persinger’s “God machine”—see Horgan (2003, pp. 91–105).
15. We will revisit this claim in the context of mystical experiences in Chapter 8.
16. A recent analysis of our collection showed that 80% of near-death experiencers described their thinking during the NDE as “clearer than usual” (45%) or “as clear as usual” (35%). Additionally, 74% described their thinking as “faster than usual” (37%) or at “the usual speed” (37%); 65% described their thinking as “more logical than usual” (29%) or “as logical as usual” (36%); and 55% described their control over their thoughts as “more control than usual” (19%) or “as much control as usual” (36%).
17. In our collection, 57% of those reporting memories said that they had experienced many memories or a review of their entire life; 43% reported one or a few memories. Additionally, in an analysis of 68 published life review cases not from our collection, we found that in 71% of these the experience had involved memories of many events or of the person’s whole life (Stevenson & Cook [Kelly], 1995, p. 455).
18. The expression “adequately anesthetized” is intended here to exclude cases of literal awakening, or partial awakening, during surgical procedures. Such awakening is known to occur, even using present-day techniques, in something on the order of 0.1–0.3% of all general-surgery procedures (Heier & Steen, 1996; Sandin, Enlund, Samuelson, & Lennmarken, 2000). Higher rates occur, as might be expected, when muscle relaxants are used in combination with low levels of anesthetic agents. Other causes of awakening include operator errors, equipment failures, inability to use sufficient agents because of excessive loss of blood in trauma cases, and unusual tolerance of particular patients to particular agents. The phenomenology of such awakenings, however, is altogether different from that of NDEs, and often extremely unpleasant, frightening, and even painful (Osterman, Hopper, Heran, Keane, & van der Kolk, 2001; Spitellie, Holmes, & Domino, 2002). The experiences are typically brief and fragmentary, and primarily auditory or tactile, and not visual; for example, the patient may report hearing noises or snippets of speech, or briefly feeling sensations associated with intubation or with specific surgical procedures. Needless to say, anesthesiologists have strong motivation, both ethical and legal, to prevent such occurrences.
19. Many, however, did report seeing a bright or all-encompassing light which seemed to be a “Being of Light” and was often identified as God.
20. Although in neither of these cases has it been possible to obtain corroborating testimony from someone other than the person who had the experience, they illustrate a particularly important kind of experience, and we suspect that, as with many of the phenomena discussed in this chapter, we will identify more such cases if we look specifically for them.
21. The clicks were 95 dB, 100 μS/ click, 11.3 clicks/sec, in successive blocks of 2,000 clicks (just under 3 minutes/block).
22. Blackmore (1983a, pp. 143–144) thinks that she has successfully discredited the Wilmot case, and Edwards (1997, p. 20) agrees, asserting that “the case totally collapsed when it was investigated by Susan Blackmore.” Blackmore claims that the entire story rests on Mr. Wilmot’s testimony alone and that this testimony was unreliable because he had been seasick at the time. She further claims that “Mrs. Wilmot never reported having had an OBE at all.” Although Blackmore claims to have read the original reports (citing Myers’s reprinting of the case), she clearly did not read them carefully enough, and Edwards apparently relied entirely on Blackmore without reading the original report himself. In the report, both the original and Myers’s reprinting of it, letters are printed not only from Mr. Wilmot but also from Mrs. Wilmot and Miss Wilmot, corroborating the essential features of his account. Although Mrs. Wilmot never explicitly said “I had an out-of-body experience,” she did say “I had a very vivid sense all the [next] day of having visited my husband.” She also said “I felt much disturbed at his [the man in the upper berth] presence, as he leaned over, looking at us.” She further reported that “the impression was so strong that I felt unusually happy and refreshed,” in contrast to the anxiety about her husband that had preceded it. We do not unfortunately have the testimony of the man in the upper berth (who had since died), but, as we mentioned above, we do have Miss Wilmot’s testimony that he told her about his experience the next morning, before she had seen her brother and heard his account of what had happened. The case is not perfect, but Blackmore’s and Edwards’s misrepresentation of the reported facts, and offhand dismissal of testimony that conflicts with their beliefs, is indefensible at best.
23. For a review of studies estimating incidence in various populations, see Alvarado (2000, pp. 184–186).
24. Interestingly, four of Devinsky et al.’s own 10 patients described an OBE that sounds more like an NDE. One patient, for example, was involved in an automobile accident in which she suffered severe head trauma. Although she was unconscious for two hours and had 24 hours of retrograde amnesia, she remembered that, while unconscious, she had an OBE in which she saw the scene of the accident, including her own body, and heard a voice sending her back. Her seizures began one month later, as a result of the injuries she suffered in the accident. Another woman, who had had numerous generalized (or whole-brain) seizures (about two per month) for 21 years, reported only two OBEs, both of them occurring during seizures at times when she seemed in danger of dying (for example, by being strangled by the bedsheets in which she had become entangled). Another woman, who had frequent generalized seizures for six years, had her single OBE at a time when she thought she was dying during the seizure. The fourth patient, who had frequent absence seizures (about five a week for 17 years), had an NDE-like experience during her only generalized seizure. In this experience, she had an OBE in which she first saw her unconscious body, and then seemed to travel into space, where it was “gorgeous… [and] warm—not like heat, but security” (Devinsky et al., 1989, p. 1082). A voice then told her to go back, which she reluctantly did.
25. In the light of the above considerations, it strikes us as at best highly premature, and quite revealing, that the editors of Nature saw fit to declare triumphantly, in connection with their publication of Blanke et al. (2002), that as a result of this one study, which dealt with only one case, “the part of the brain that can induce out-of-body experiences has been located” (p. 269).
26. As we discussed in the Introduction, the authors of this book are united in the conviction that psi phenomena have been adequately demonstrated, both in spontaneous case studies and in experimental studies, even if there is as yet no adequate theoretical model to account for them. It is our hope that this volume will help catalyze the development of such a model. For readers who do not share our conviction, we refer them to reliable literature on this topic (see the Appendix).
27. One might ask whether Roll awoke from his OBE, not immediately after the experience as he thought, but later in the night, when earlier moonlight might have disappeared. The purpose here, however, is not to debate the details of this particular experience, but simply to call attention to the undeniable fact that many OBEs, however vivid, are not veridical.
28. It is worth noting, however, when considering this suggestion, that she called the five digits out in their correct left-right order (Tart, 1968, p. 17).
29. For an excellent brief discussion of Myers’s theory, which he called “phantasmogenetic efficacy,” see Gauld (1982, pp. 250–260).
30. Blanke et al. (2004) and Brugger, Agosti, Regard, Wieser, and Landis (1994) also call attention to transitional experiences, called “heautoscopic,” in which the subject alternates between these two perspectives, or even experiences both simultaneously.
31. This apparent association with pathology, however, may simply reflect a reporting bias, since most studies of autoscopy have been published in medical journals.
32. It was many years before anyone took up this suggestion, but one of the earliest reports about lucid dreams was published in the SPR Proceedings by Myers’s friend and colleague, Dr. F. van Eeden (1913).
33. These methods involve subjects signaling with pre-specified voluntary eye movements, verifiable by outside observers, that they are having a lucid dream (LaBerge & Gackenbach, 2000, p. 157–163).
There is another interesting parallel in the history of research on NDEs and lucid dreams: Blackmore has suggested that NDEs must occur in the moments just before losing consciousness or just before fully regaining it, when brain processes are not so seriously impaired. Similar explanations were proposed for lucid dreams by sleep researchers whose assumptions about the nature of sleep did not allow for the “paradoxical” concept of “conscious sleep”; they argued that lucid dreams must occur either in brief awakenings or in non-REM phases of sleep, until methods were developed demonstrating that lucid dreams do occur during REM sleep (LaBerge & Gackenbach, 2000, pp. 157–158).
34. A “positive” hallucination is one in which a person sees a person or object that is not physically present. A “negative” hallucination is one in which a person does not see a person or object that is present.
35. Many cases identified in this study, in which the person reported simply a “sense of presence” or a “dream” coinciding with a death or other crisis, may also have involved apparitions, but even if not, they are clearly related to the apparitional cases. A “sense of presence” may in fact be an incipient apparition, as suggested by a few cases reported in which an initial sense of presence then developed into a sensory apparition (Gurney et al., 1886, vol. 1, p. 483, 527–531).
36. As we pointed out in Chapter 2, Myers coined the word “telepathy” in 1882 to refer to the phenomenon of one person apparently deriving information directly from another person’s mind.
37. Gauld (1968, pp. 168–171; 1982, pp. 238–242, 250–260) has presented summaries of these two views. In 1968 he was clearly not persuaded by either of them, but by 1982 he took Myers’s theory more seriously.
38. Reports of such “Peak in Darien” experiences may be found in W. F. Barrett (1926, pp. 10–26), Callanan & Kelley (1993, pp. 89–90,98–99), Cobbe (1882, p. 297), Crookall (1960/1966, pp. 21–22), Gallup and Proctor (1982, pp. 13–14), Gurney and Myers (1889, pp. 459–460), Hyslop (1908, pp. 88–89), A. Johnson (1899, pp. 288–291), Kübler-Ross (1983, pp. 208–210), R. A. Moody with Perry (1988, p. 136), in HP (vol. 2, pp. 339–342), Osis and Haraldsson (1977/1997, p. 166), Ring (1980, pp. 207–208), E. M. Sidgwick (1885, pp. 92–93), Spraggett (1974, p. 95), and Stevenson (1959, p. 22).
39. This person’s experience is reminiscent of the experience described by St. Paul in which he said “whether in the body, or out of the body, I cannot tell” (2 Corinthians 12:3).
40. As we will discuss in Chapter 8, however, such transformations are commonly associated, not just with religious “conversion” experiences, but with mystical experiences in general, including the mystical-type experiences sometimes reported in connection with the use of certain drugs.
41. James interpreted conversion experiences in just this way, saying that the “discovery of a consciousness existing beyond the field of consciousness, or subliminally as Mr. Myers terms it, casts light on many phenomena of religious biography,” and that “possession of a developed subliminal self, and of a leaky or pervious margin, is thus a conditio sine qua non of the Subject’s becoming converted in the instantaneous way” (James, 1902/1958, pp. 188, 194).
42. A small percentage of other cardiac arrest patients in these studies reported some memories during the arrest, but not enough to qualify for an NDE as judged by the Greyson NDE Scale (Greyson, 1983b, 1985) or the Ring WCEI (Ring, 1980).
43. Hartmann (1989, 1991) and Thalbourne (1998; Thalbourne & Delin, 1994) have proposed similar ideas about factors influencing the exchange of material between levels of the mind, and both have developed questionnaire instruments capable to some degree of measuring these factors—”boundaries” and “transliminality,” respectively.
44. The specific brain regions involved vary somewhat according to the tasks and theorists, but characteristically include cerebellar and limbic cortex, anterior cingulate and insular cortex, the thalamus with its dense and reciprocal connections with neocortex, and large parts of the neocortex itself, including in particular frontal and parietal cortex as well as whatever specific sensory systems may be momentarily engaged (see, e.g., Baars, 1997; Crick, 1994; Dehaene & Naccache, 2001; Edelman & Tononi, 2000; A. K. Engel et al., 2001; W. J. Freeman, 2000; John, 2001; Llinás, 2001; Mesulam, 2000; Varela et al., 2001).
45. A similar line of argument could be developed, we believe, for related conditions such as coma and persistent vegetative state, during which NDEs have also occasionally been reported. We focus here on general anesthesia and cardiac arrest only because the relevant physiological conditions are relatively well characterized and the cases already numerous.
46. Representative of people who have completely missed the mark here is Woerlee (2004).