The human brain, removed from its protective shell, the skull, looks something like a large walnut half, deeply fissured and split into two parts by a deep central crevasse. These two parts of the brain, known as hemispheres or lobes, are connected only by thick bundles of nerves. Through observation of the effects of head wounds, humans have known for thousands of years that damage to the left side of the brain has different effects on the injured person’s mental and physical capacities than damage to the right side of the brain. Then, in a series of extraordinary studies during the 1960s, brain researchers Roger Sperry, Michael Gazzaniga, Joseph Bogen, and others studied the brains and capabilities of patients who had undergone radical surgery that totally separated the two hemispheres by severing the corpus callosum, the thick band of nerve fibers connecting them. These now historic studies caused excitement and astonishment by demonstrating that not only does each hemisphere of the cortex have its own train of conscious thought and its own memories, but that the two sides think or operate in fundamentally different modes.
Left Brain. As research progressed, evidence piled up that the brain is “crosswired” to the body—with the right hemisphere controlling the left half of the body, and the left hemisphere controlling the right half and that for the majority of people the left hemisphere is dominant. This left brain seems to think analytically, sequentially, logically, with an orientation in time.
Right Brain. The right brain, on the other hand, tends to process information in a mostly nonverbal, simultaneous, intuitive, nonlinear, timeless, imagistic manner. It seems to be the seat of those flashes of insight that have been called the Eureka event.
A recent study by brain researcher Justin Sergent, of McGill University, has challenged this familiar theory of hemispheric function; the study proposes that the left hemisphere excels at detail, processing in formation that is small-scale, requiring fine resolution, while the right hemisphere is best at pattern recognition and large-scale, non-detailed processing.43 The right brain is by nature a good guesser, rapidly absorbing information in broad outline, while the left hemisphere must take its time and deal with details. Although this new research questions certain assumptions of the usual right/left paradigm, it actually reaffirms the essential differences in function between the two hemispheres: In a sense, the right hemisphere supplies the shape and the frame, while the left fills in the details.
Sinister Thoughts, Subversion from the Left
As research into brain lateralization progressed and scientists began to understand how the dominance of one or the other hemisphere could not only color one’s perceptions of external reality but actually determine the reality one perceived, it became clear that our culture valued and cultivated those qualities associated with left-brain activity more than it did those of the right brain. Many have noted, for example, that even the word right has positive connotations beyond those of physical position: The very concept of “rightness” as that which is correct, upright, fit, convenient, free from guilt, is opposed by the concept of leftness, with its connotations of evil (the Latin word for left is sinister). Probably the most stunning demonstration of how completely oriented toward the left brain our culture is, is the fact that surgeons have removed the entire right hemisphere from conscious patients without their noticing the slightest st change tit awareness.
Left-hemisphere dominance is powerfully reinforced by our educational system. When we’re born the two hemispheres seem to work independently but with equal powers. In their play, their fantasies, their thinking, children show strong right-brain activity—they’re diffuse, intuitive, visual, musical, and they seem to have no sense of time, responding to unpredictable inner rhythms. But in the primary and secondary schools, these right-brain qualities are causes for criticism or even punishment. Fantasizing is not welcome in the classroom, teachers are not usually receptive to intuitive answers to questions, and in every classroom there is a large clock on the wall. Students who won’t curb their right brains are seen as day dreamer, dawdlers, lazy, disruptive.
By the time students reach college, left-hemisphere dominance is firmly established. Skill at using the verbal, analytic hemisphere is rewarded by good grades. Yet in one experiment, college students were tested in their intuitive thinking ability, and when the results were compared to the students’ grade point average, there was almost no correlation at all; the study concluded that “intuitive thinking is clearly unrelated to college grades.”259
While left-brain skills are rewarded by good grades, and are highly valued by our culture, they are not sufficient for complete functioning and a fully rewarding life. In fact, most productive thinkers and all recognized geniuses have insisted that their ideas and creative energies have flowed from that deep pool of wisdom that has been called the unconscious. Logic, words, and details are important, but they are only tools; they are not reality themselves, but useful symbols or means of approaching reality. To be effectively used, they need the intuitive, large-scale, synthesis-making abilities of the right hemisphere.
In recent years many have recognized the dangers of left-hemisphere dominance and have undertaken in various ways to emphasize the right-brain functions. Meditation, yoga, Zen, consciousness-altering drugs, chanting, dancing, running, guided dreaming, visualization, self-hypnosis, and many other techniques have been used to open up the right hemisphere. But all the evidence now available suggests there is no more reliable and efficient way for a human to gain access to the contents of the right hemisphere than by entering a float tank for an hour or so.
Research into the brain waves of the two hemispheres of floaters indicates that floating increases right-brain function. Thomas Budzynski, who is engaged in EEG measurement of the hemispheres under varying conditions, made it clear in a speech he delivered at the Denver REST conference. “In a float condition,” he said, “left-hemisphere faculties are somewhat suspended and the right hemisphere ascends in dominance.”38
While an increasing amount of research evidence demonstrates that floating has this effect of opening up the right hemisphere, anecdotal evidence is just as impressive. Of the scores of people I have talked with about floating, every one of them has mentioned some incidence of sudden awareness of right-brain activity. Paul, the young architect with the broken shoulder who went into the tank to ease his pain, was surprised to note an increased ability to visualize architectural details, solve problems, and create with an originality surpassing anything he had been capable of before. Chris, the fashion model who’d never been able to talk herself out of her anxiety, rid herself of it by using the images that flowed from the nonverbal right hemisphere. Arthur, the scholarly Ph.D. who had always gotten high grades but had never been able to form a satisfactory relationship with a woman, fascinated with details but scornful of religion—surely a left-brain-dominant person—suddenly found himself filled with a deep sense of wholeness, harmony, and a new vision of how to love. It was, he said, “a totally new kind of communication with myself.” The communication was with his previously inhibited right hemisphere and its ability to see things in a large-scale, unified way.
How does the tank accomplish so easily what many must work and train for in rigorous meditative techniques? To use the day-night metaphor, in the sunshine of the day it is impossible to see the faint bits of light scattered through the sky by the millions. Just so are the diffuse, subtle contents of the right hemisphere drowned out and overpowered by the noisy chattering of the verbal/analytical hemisphere. Floatation, by turning off the external stimuli, plunges us into a literal and figurative darkness, where suddenly the entire universe of stars and galaxies is spread out before our eyes.
Floating enables left-dominant people to gain access to the right brain more readily than other techniques do because the other methods seek to make people experience something whose location is still a mystery to them—like telling someone to look very hard for stars at high noon of a sunny day. People have developed such powerful strategies to maintain left-brain dominance that they simply refuse to relinquish them. The chatter never stops; the sun of consciousness never sets. Even the thought of nightfall fills them with a deep dread—at night the wild beasts prowl.
In the tank, on the other hand, there is no struggle to guide the left-oriented person toward some ill-defined right-brain awareness. You close the door, the light goes out, the chatter stops, and there it is.
Two Halves Make a Whole: Hemispheric Integration
Despite the immense importance, even necessity, of being open to the large-scale, creative, unifying vision of the right hemisphere, it would be a mistake to think that right-brain thinking is somehow “better” or on a higher moral plane than left-brain thought. Many who have correctly perceived the importance of the nonverbal hemisphere, and have realized the damage done to our culture and our world by left-brain dominance, make the error of viewing right-brain dominance as a noble goal. “Look where logical, analytical, verbal thinking has gotten us,” they seem to say. “Our only hope is the right hemisphere! All power to the right brain!” They then plunge into the dark depths of the unconscious.
To call those depths dark is no mere figure of speech. Neurologist Marcel Kinsbourne points out that the different hemispheres are not only specialized for mental processes but also that “it is now becoming increasingly clear that each hemisphere also supports a different emotional state. Neuropsychologists in several countries have found evidence that the right hemisphere is involved in negative feelings and their expression, while the left is associated with positive feelings and their expression.” Citing split-brain studies, Kinsbourne asserts that “the left hemisphere of the split-brain person seems to be innocent of evil.”129
One brain researcher has shown films to experimental volunteers through special lenses that allow the films to be seen by the right or left hemisphere only; the experiments showed, says Carl Sagan, “a remarkable tendency for the right hemisphere to view the world as more unpleasant, hostile, and even disgusting than the left hemisphere…. The negativism of the right hemisphere is apparently strongly tempered in everyday life by the more easygoing left hemisphere. But a dark and suspicious emotion tone seems to lurk in the right hemisphere, which may explain some of the antipathy felt by our left hemisphere selves to the ‘sinister’ quality of the left hand and the right hemisphere.” 204
An explanation for this may lie in the fact that, as noted, the right hemisphere deals with information on a broad scale, tending to perceive things as shapes and patterns. However, seeing patterns and unity in external reality is a characteristic of what we call paranoia. There’s no way we can know whether the patterns our right hemisphere discerns are real or imagined unless we submit them to the more detailed evaluation of our left hemisphere. On the other hand, as Sagan points out, “Mere critical thinking, without creative and intuitive insights, without the search for new patterns, is sterile and doomed. To solve complex problems in changing circumstances requires the activity of both cerebral hemispheres.”
McGill researcher Justin Sergent, who contends that the left brain specializes in detailed processing, the right in pattern recognition and large-scale processing, concludes: “This points to a cooperation between hemispheres whose respective limitations and predispositions allow for complementary capacities in processing information.”43
While we’ve known of the lateralization of the brain’s functions for only a few years, the dangers of the imbalance of the two brains, of what Charles Hampden-Turner calls the “pathology of splitting,”94 have been known to us for millennia. The perception of the harm done by the incapacity of the two lobes to harmonize and integrate was probably one of our species’ earliest and clearest, and certainly remains one of its most deeply felt, symbolized in such potent myths as the Fall of Man, the rending of the Veil of the Temple, the shadow self or the double or doppelgänger, and in the “splitting” of schizophrenia, the antagonism between male and female, the existence of God and Devil, and so on.
The remedy for this dangerous internal division has also been known for millennia; virtually every religion, philosophy, psychology, and healing practice has stressed that the road to ultimate wisdom and health lies through a balancing and harmonizing of the functions of the hemispheres, symbolized variously as the unity of yin and yang, day and night, mind and body, consciousness and unconscious, ego and id, creative and receptive, heaven and earth, male and female, inner and outer, self and others—seen not as oppositions but rather as complementary parts of a single whole, brought into proper relation, which can be called symmetry, dialectic, harmony, resonance, congruence, dialogue.
Although techniques for attaining this harmony have been taught as long as there have been humans, it has often been assumed that the concept of symmetry was merely the metaphor. While this may be partially true, we’re now discovering that the ideas of symmetry and integration are also true in the most literal and concrete way. Various experimenters have used a variety of equipment, including the EEG and the PET scan (positron emission tomography, in which a radioactive isotope injected into the bloodstream is carried to areas of high metabolism—e.g., the brain—so that a picture can be taken), to measure the activity of the two hemispheres while the subject is in various emotional states and performing various mental functions. Their conclusions have been clear:
British psychologist C. Maxwell Cade, recording electroencephalograms of more than four thousand people, discovered that “all the unusual abilities that some people are able to manifest (self-control of pain and healing, healing of others, telepathy, etc.) are associated with changes in the EEG pattern toward a more bilaterally symmetrical and integrated form.”40
Dr. Bernard Glueck, director of research at the Hartford Institute of Living, conducted extensive tests on large numbers of meditators, and found that the EEG patterns of successful meditators showed an increased synchrony between the left and right hemispheres; that is, both sides functioned together, in harmony.84
Neurologist J. P. Banquet also did EEG studies of meditators, and provided push buttons so that the subjects could signal when they were entering different levels or stages of meditation. Banquet noticed that when meditators signaled they were in “deep meditation” or “pure awareness,” their brain waves had become in phase, and synchronized in both hemispheres of the brain, a condition Banquet called hypersynchrony. He concluded that this harmony of hemispheres is the single most outstanding EEG characteristic of “deep” states of consciousness.10, 11
Such findings have led writer Peter Russell, author of The Brain Book, to conclude: “As a species we seem to be moving in the direction of greater communication between the two halves. A similar phenomenon seems to be happening at the level of individual evolution, personal development of awareness resulting in an increased communication between the hemispheres.203
This evolutionary step forward means we’re learning to use our brains more efficiently. The specialization in function of the separate hemispheres, in fact, has the value of increasing our brain capacity. Each hemisphere analyzes the input in its own style, and only then exchanges information with the other half, after much initial processing and sorting is already completed. Budzynski, along with other brain researchers, has compared this to having two separate computers in our heads. We are thus “able to run two programs on everything that happens to us,” he says, “and then choose the best one. That’s where we have the big jump on lower animals.” By our access to two simultaneous streams of information which we can compare and integrate, we are made simply more intelligent. Research is now, underway to measure the brain waves of both hemispheres while the subject is in the tank, using a waterproof “electrode cap,’’ but preliminary studies (EEGs made of floaters who have just emerged from the tank) indicate that this synchronization and balancing of hemispheres does take place during floatation.
Synchronization of brain waves, hemispheric harmony, is one explanation for the great increase in productivity, performance, and efficiency, and the generalized feelings of competence, confidence, and wholeness experienced by floaters. Recall, for example, Arthur’s “special sort of communication” with himself, which resulted in “a feeling of unity of all things, harmony, wholeness.” The tank does not block or inhibit the left hemisphere, but simply changes its role from one of dominance to one of partnership with the other hemisphere, enabling floaters to use all their mental powers.