Zen-Brain Horizons

New Research Horizons

The essence of things is just this. If even one thought appears, that is already a mistake.

While my inner monologue unrolls, I have the impression of not being free.

Hubert Benoit ²

This chapter serves as a reminder: thoughts are an integral part of daily life. Thoughts are as natural as clouds in the sky. However, excessive thoughts distract from the clarity of awareness. From its inception, the Path of Buddhism has sought the balance of a Middle Way.

Concise Advice about “No Thinking”

We had not met before. This preliminary interview took place before the retreat started. The two of us had just sat down in facing chairs. The Zen Roshi spoke first. “Remember this,” he said. His next six words supplied the essence of the mental attitude I would need during the week-long Zen retreat:

“No doctor. No God. No thinking.”

The advice stripped this new student of all professional vanity. It negated any possible need (that even a Unitarian might retain) for some lingering theological attachments. It epitomized the Rinzai Zen approach to meditation: let go of discursive thoughts!

Discursive Word-Thoughts

To Hubert Benoit, the French psychologist, each person’s Self-centered world was “the world of speech.” The evidence was obvious: Every word-thought is verbal in nature. Moreover, each word-thought conveys only relative meaning, not real, tangible meaning. Therefore, at least from a Zen perspective, his 1973 book invited us to “let go” of this strong primary attachment to language. In its place, he advised readers to cultivate other “automatisms of divergence.”

This first proposal—to “let go”—might seem to restate some of the Buddha’s early advice to Bahiya about letting go of attachments. We observed how Zen masters during later centuries incorporated this teaching into their training methods (see chapter 5). In this twenty-first century, how does such age-old psychological advice translate into neural terms? The counsel in these pages is straightforward: Abandon unfruitful Self-centeredness; free more lower pathways from being entangled with egocentric word-thoughts. As a result, you will open them up for more allocentric processing. But what did Benoit mean by “divergence”? And which of its “automatisms” were to be cultivated?

Divergence in the Context of Meditation and Creativity

Things that diverge spread apart from a common point of origin. When divergent thinking branches out it increases the number of creative options. On the other hand, too much diversity interferes with the next process of selecting which option is best. So, what absolute requirements do creativity and meditation each seem to share? At a minimum, they both require (1) flexible alternations between narrowly focused attention skills and global awareness skills, and (2) precise timing of each such skill set on the leading edge of just the right kinds of convergent and divergent processing, respectively.³ [SI: 109–112] All along, our fluid intelligence performance improves when there is less cognitive and emotional dissonance, rather than more.

Williamson and colleagues conducted a pilot study of five adults who averaged 41 years of age.⁴ None had meditated previously. The researchers wondered, How would a well-taught eight-week course of mindfulness-based stress reduction (MBSR) influence these subjects’ divergent and convergent reasoning? The authors preferred the Torrance test for its dual capacities to examine both the visual and verbal domains of creativity. In brief, they found that verbal creativity and flexibility improved significantly; the trend toward nonverbal creativity was less pronounced.

Yet, students are introduced to a lot of new verbal instruction and to language in general during any such course. How much does all this exposure influence their subsequent verbal performance? Dotan Ben-Soussan et al. studied 27 women, nine of whom were enrolled in a particular whole-body physical training practice.⁵ This motor task is called Quadrato. Its verbal instructions are precise, simple, and delivered by audiotape. The tape directs the trainees to take only a single step. However this step might take them forward, or backward, or to the left, right, or diagonally. This five-step, at random unpredictability creates a climate of attention plus uncertainty. The trainees performed this audio-directed random task for 7 minutes within a square space on the floor. The space measured only 20 inches (50 centimeters) on each side. Thereafter, all subjects were tested using the Alternate Uses Task for creativity. In contrast to the creative performance of the two control groups, the Quadrato subjects significantly increased their ideational flexibility (but not their ideational fluency). They also increased their frontotemporal alpha EEG coherence bilaterally.

Colzato and colleagues also used Guilford’s Alternate Uses Task as a way to assess the productivity of divergent thinking, and used Mednick’s Remote Associates Task to assess the results of convergent thinking.⁶ The 19 meditators in their study had already practiced a mixture of concentrative and receptive forms of meditation for an average of 2.2 years. The task for each subject was to spend only 35 minutes a day (on each of three separate days) either in concentrative meditation or in receptive meditation or in a baseline control condition. Receptive meditation did improve the subjects’ divergence on the Alternate Uses Task, as expected. However, both types of meditation improved mood. Why did the researchers wonder whether the energizing influence of mood might account for some of their subjects’ productivity in divergent thinking? Because positive mood (accompanied by increased fMRI signals in the anterior cingulate cortex) has been reported as occurring during those intervals when normal subjects solve problems insightfully.⁷ [SI: 19–20]

Takeuchi and colleagues studied the creative performance of 159 young adults in a university population.⁸ They correlated the subjects’ fMRI data with their responses on a separate divergence-type test (similar to the Torrance test employed by Williamson et al.). Subjects who scored higher on divergent thinking had greater degrees of resting connectivity that linked their medial prefrontal cortex with their posterior cingulate cortex. When an external task captured these particular subjects’ attention, this medial (“attention off”) network region deactivated less than it did in the controls.

Abraham et al. issued an appropriate caveat when they surveyed the literature. They acknowledged how difficult it is to conduct meaningful neuroimaging research on a topic as complicated as creativity.⁹ They designed their fMRI study to emphasize a process that they called “conceptual expansion.” Their 19 university students worked to perform an Alternate Uses Task under the pressure of time constraints. Under these timed conditions, their subjects’ task-induced conceptual expansion correlated with greater left-sided activation in their anterior inferior frontal gyrus (BA 45/47), their lateral frontopolar cortex (BA 10), and in the medial aspect of both anterior temporal poles (BA 36) (see figure 3.1).

Ellamil et al. conducted a landmark study of visual creativity in 15 subjects. These students, averaging 22 years of age, were specializing in art and design at a local university in Vancouver, BC.¹⁰ The students had a novel, practical task. It was to design an actual book cover using an fMRI- compatible drawing tablet. The researchers distinguished between divergence at the start of the task, when several ideas were first being generated, and the processing during later intervals, when ideas were being critically evaluated and selected.

When the students were first generating novel ideas, they recruited two medial temporal lobe regions: the hippocampus on the right side and the parahippocampus on both sides. Later, during the phase of evaluation/selection, they jointly activated the standard executive and default networks. In addition, they also activated the left anterior insula plus both temporal polar regions (L>R). [SI: 31, 160-161, 238]

Harré and colleagues took a different tack.¹¹ They wondered why experts could solve intricate problems of great complexity. Their theory: experts would have gradually developed transformations farther back within “the early sensory region of the brain.” It was these proposed changes that would give experts an implicit “preprocessing” advantage. Elsewhere, the term preattention has served to identify the leading edge at the tip of this preprocessing. [SI: 139–141]

• Why is the word implicit applied to these covert steps in perceptual learning?

Because the perceivers are not aware of two things: (1) They do not know exactly what they have learned, (2) They do not comprehend how their prior years of training could have transformed their thoughts and behaviors. In short, implicit learning happens subconsciously. And it remains there, out of sight and out of mind, until propitious circumstances liberate it. [MS: 136, 155, 171]

To test their theory, Harré et al. analyzed the actual performance records of many expert professionals who were playing against amateurs during 18,000 games of GO. In this oriental game of skill, two players compete by moving their marble-like pieces on a board. The winner is the player who annexed the most territory. Formal analysis of this mountain of data supported the existing hypothesis: these experts appeared to have developed their preprocessing skills by using what might be called perceptual templates. Each such gist, confirming covert perceptual expectations, helped them instantly categorize whole complex scenes.

Supporting evidence about such games of GO comes from the diffusion tensor image (DTI) study by Lee and colleagues at Seoul National University.¹² This new imaging technique exposes the brain to a shifting magnetic field. The resulting displacements create measurable shifts in the ways water molecules diffuse through the micro-architecture of white matter. The authors’ 16 GO experts averaged 12 years of training. The 19 controls had no special training or interest in such games. In brief, at two sites in their white matter the GO experts showed the most consistent increases in their fractional anisotropy (FA). These sites were in the right frontal/subcortical and left inferior temporal regions. With regard to the temporal lobe themes discussed earlier (see chapters 11, 12), these two temporal lobe regions notably included the fusiform gyrus and the inferior longitudinal fasciculus. The increased FA values in these two inferior temporal regions were interpreted as consistent with the kinds of neural template mechanisms that could provide GO experts’ with the instant decoding they needed during early visual processing.

Chess expertise seems to involve a horse of a different color. In Tübingen, Germany, the eight chess experts (in the top 1 percent) studied by Bilalic et al. had faster reaction times than did the 15 chess novices.¹³ They also had greater fMRI activations in the following four regions: the junctional region where the lateral parietal, temporal, and occipital lobes all come together (see figure 2.1); the supramarginal gyrus (L); and medial regions like the retrosplenial cortex and the parahippocampal cortex (see figure 3.1).

Differences between the Right and Left Temporal and Frontal Lobes

Chapter 13 deferred a key question: Could our right and left temporal lobes perform remarkably useful functions in ways sometimes so different, indeed so ill-timed, that such a lack of flexibility might cause them to work at cross-purposes? Surely, our left temporal lobe has many practical multimodal functions to perform, not just the specialized role it plays in language processing.¹⁴ Indeed, as the GO studies indicated, when these processing streams ramify farther forward toward the anterior pole of the temporal lobe, their normal associative capacities seem to resonate among template networks in subtly intelligent ways. The net results illustrate the wide variety of our other higher-order pattern recognition and interpretive functions. [ZB: 247–253; ZBR: 152–157]

Neurology began the old-fashioned way. It was a way that said, If you want to find out how the normal brain works, notice which clinical deficits occur after a discrete region of gray matter was damaged. Nowadays, researchers are asking, What symptoms occur when the left anterior temporal lobe cortex is merely disorganized briefly? Investigators can now use transcranial magnetic stimulation (TMS) to create such a temporary, unilateral disorganization. In normal volunteers, TMS can cause a brief loss of normal high-level temporal lobe conceptual functions.¹⁵ The nature of the resulting 10-minute deficit confirms what researchers expected to find: our left anterior temporal lobe seems to serve normally as a conceptual hub. Normally, a sense of semantic meaning emerges as this high-level decoding matrix processes the information that reaches it from transcortical and subcortical sites.

In 2006, Han and colleagues at Beijing University employed a different approach.¹⁶ They wanted to study the normal functions of the right temporal lobe. [SI: 135–138] They used functional MRI to monitor 12 subjects who were being shown a series of static film clips. They had extracted these isolated frames from various parts of a short movie. Their subjects’ task was to answer this action-based, visual question: Do you recognize any logical plot underlying this sequence of separate visual scenes? Three right-sided regions increased their fMRI signals only when the subjects linked these separate visual episodes into one coherent plot. These regions were the right middle temporal cortex (BA 21), the right posterior superior temporal cortex (BA 42), and the right inferior postcentral gyrus (BA 1, 2, 3). The regions did not co-activate when random episodes fell into no meaningful sequence.

Asari et al., at the University of Tokyo Medical School, preferred inkblot responses. They presented their 68 normal adults with ten different Rorschach inkblot stimuli.¹⁷ Simultaneously, they monitored these subjects’ fMRI signals and their spontaneous verbal responses. Which site was significantly activated whenever the subjects voiced singular, novel responses to these ambiguous figures? The polar cortex of the right anterior temporal lobe.

Dense anatomical connections link this region at each anterior temporal pole with the amygdala, with the inferotemporal cortex more posteriorly, and with the nearby orbitomedial prefrontal cortex. Notably, connectivity analyses suggested that activity in the subjects’ amygdala (L>R) was enhancing the degrees of connection that would link their left anterior prefrontal cortex with their right temporal pole. However, this activity in their amygdala also had a different role to play in the back of the brain. It usually appeared to reduce the connectivity between this right temporal pole and those regions farther back in their occipitotemporal cortex. The two sets of findings are interpretable and complementary: (1) Our personal memories, our imagination and perceptions seem to respond in complex ways to emotional messages arising from the amygdala, and (2) simultaneously, the nearby temporal pole could act to integrate this information into novel projective responses, the kinds that infuse imagination into processing.

In 2012, Cohn et al. also wished to test the capacities of normal subjects to detect visual coherence and incoherence.¹⁸ They chose static visual images that held a special appeal for their American subjects. These sequences of single frames were extracted from the popular “Peanuts” comic strip. Notice that none of these images contained words. The subjects’ reactions were monitored using visual event-related potential (VERP) responses. In brief, the results suggested that visual coherence arrived when a sensitive left-lateralized anterior neurocognitive mechanism became involved. This waveform arrived 300–400 milliseconds after the visual stimulus. The wave complex appeared to be reacting in a “pattern-predictive” manner at the same time that two mental themes converged. One theme represented the larger structure of an emerging, global, coherent narrative. The other component seemed to involve lesser events that could represent discrete sources of meaning. The anterior location of this particular VERP waveform is a point of further interest. It could be consistent with the possibility that the nearby inferior frontal and temporal regions on the left side were pooling some joint resources. Such a combination could help to infuse a larger narrative meaning into a series of images even though no actual words were attached to any of those separate visual frames. [ZBR: 213–214]

•2013046636But is it always useful to cling to only one fixed meaning that might arise from some hub over in one temporal pole and nearby frontal region?

Why not think outside the box, loosen up such high-level concepts, and create a different narrative structure, one that can access other options? [SI: 123–188] For example, let’s start with the important region around the left anterior temporal lobe hub. Suppose this hub were to become less active, whereas at the same time those other higher-level functions on the right side became more active. Now what could happen?

This could have seemed a far-out question even as Chi and Snyder prepared to answer it at the University of Sydney, in Australia.¹⁹ Notice that the technique they chose delivered a particular kind of gentle stimulation to the brain. This method involves the transcranial passage of direct current (tDCS). This is non-magnetic stimulation at low amperage (1.6 milliamperes). When the cathodal (minus) DC electrode is placed on the scalp over the left anterior temple, the resting potentials of nerve cells are rendered less likely to fire in the underlying left anterior temporal lobe. However, by placing the anodal (plus) electrode on the scalp over the subject’s right anterior temporal lobe, the nerve cell excitability of this right anterior temporal lobe region is facilitated. These reciprocal modulations occur simultaneously. They create less activation on the left but more activation on the right. An extensive literature supports the basic principles involved in this line of research.²⁰ ^–22

The normal subjects had to solve difficult insight problems while they were receiving tDCS and for many minutes after it stopped. These tasks use matches to indicate Roman numerals. Each problem must be solved by moving only one match stick. For example, try to change this false statement (11 equals 6) into a true statement by moving only one match:

XI = III + III

Why is this task so hard to solve? We have already limited our options. We have set up several rigidly conditioned restraints. One of the places we stay stuck is in a conventional logic-tight construct. It asserts that once an X is crossed, it must stay crossed. Who says so? Whose mental sets become so flexible that they can envision sliding one of these matches over a bit? Who can cut free from their ingrained force of habit, allowing this X to diverge into a more open V? During tDCS, three times as many normal participants could become more open-minded. They did solve such problems, in contrast to control participants who had received only sham stimulation. [SI: 183–186, 298]

In brief, what the subjects needed to do was to let go of their prior conventional constraints. Their imagination needed to open up, to embrace fresh insights and novel meanings. Single solutions happened to arrive after their right anterior temporal lobe circuits were not only gently facilitated but also potentially liberated. From what? Liberated from prejudgments, inhibitory constraints, and distractions previously imposed by ill-timed contributions from their left anterior temporal lobe. Could these complications be related to cross-talk received from some of the left side’s extensive language-entangled functions?

This same direct current stimulation (tDCS) technique was then applied to other normal subjects during a second experiment.²³ Their task was to solve the much more difficult nine-dot problem. How can anyone solve this task? The only way is to literally think outside the box (see the illustration at the start of part V). But word-thinking is not the way to proceed. Why not? Because our intrusive Self, following convention, imposes another rigid conceptual constraint. Its boundary rules caution, “Stay inside the box.” Silently, we obey our old, habitual mind-sets. No participants could solve this tough problem before they were stimulated or while being exposed to the sham control conditions.

When could 14 out of the 33 participants arrive at the correct solution? When the passage of direct current tended to reduce the functions of their left anterior temporal lobe at the same time that this current was facilitating the functions of their right anterior temporal lobe. It need not be assumed that every change occurring during tDCS or lingering for a hour or so thereafter must be confined solely to events generated at this cortical level.^24, ²⁵

These new tDCS observations reopen old discussions. When each of us pursues our highly individualistic approach to creative problem solving, how do our right and left hemispheres blend their dynamic positive and negative contributions? When we are faced with a formidable problem, do we have a single, well-defined goal? Is it to perform a quick, flexible, critical, yet balanced appraisal while seeking only one best solution? [SI: 153–158] If so, then we must keep shifting skillfully, flexibly, at just the right times, avoiding not only premature attachments to each fresh option but also overcritical rejections.

With one swift stroke, Isaac Newton (1642–1727) used a glass prism to split white daylight. Six rainbow-like bands of color emerged. Today’s neuroimaging researchers are trying valiantly to untangle the six interwoven strands of creativity. Yet no comparable system on the technical horizon has this elegantly simple capacity to split creativity into its six interactive themes. They are interest, preparation, incubation, illumination, verification and exploitation.²⁶

• Could long-term meditators develop enduring changes in the pathways that interconnect the diverse gray matter regions in their brains?

Luders et al. first reviewed the latest literature relating to this large crucial topic. Then they described the results of their own study of meditators at UCLA, aided by diffusion tensor imaging (DTI).²⁷ Their 27 subjects were much older than meditators in the usual neuroimaging study. They averaged 57 years of age. Moreover, these meditators had been practicing for a very long time—an average of 23 years—and represented three major traditions of Buddhist practice. The results were contrasted with the DTI data found in the white matter of an equal number of age-matched normal controls.

The meditators showed a generalized increase in this DTI index of connectivity. The evidence was present in 20 separate white matter tracts. The increase was especially noteworthy in two major connection pathways that link the functions of their frontal and temporal lobes. One major path was on the left side: the superior longitudinal tract where it traverses the superior temporal gyrus. The other major path was the uncinate tract. It connects each inferior frontal lobe with its corresponding medial temporal lobe. This uncinate tract was involved on both right and left sides. Moreover, increases also occurred in two white matter tracts within the left temporal lobe itself: in the inferior longitudinal fasciculus and in that same branch of the left superior longitudinal fasciculus that courses farther into the left superior temporal gyrus. These two left-sided increases correlated with the subjects’ increasing age, not with how long or how frequently they had practiced.

• Was such evidence of neuroplasticity, when measured only at a single endpoint after two decades of meditation, accompanied by any pertinent psychological evidence? More specifically, were individual meditators more mature in their intra- or interpersonal relationships?

No data from that cross-sectional survey nor personal data supplied in this book testify either to the original immature baseline status or to the mature adult status of each person’s psychological nature. All during these decades the meditators were exposed to the cumulative effects of four relevant mechanisms: (1) meditative nurture, (2) aging processes in general, (3) the usual kinds of maturation, and (4) the kind of Jamesian maturation that helps build extra character when we deliberately confront real-life daily experiences and seek to surmount other major challenges (see chapter 7). In fact, we do not know precisely which inhibitory, disinhibitory, and excitatory mechanisms had changed which psychophysiological attribute during any subject’s decades of development.

Ample room remains for rigorous future longitudinal research. We still need to clarify what lay practitioners and monastics actually do when they meditate;²⁸ how the effects of implicit learning can be explained on the basis of each individual meditator’s mechanisms of neuroplasticity; and how the resulting reorganizations in each brain can become overtly manifest daily in measurable degrees of that person’s authentic, real-life, selfless compassion.²⁹ [MS: 42–52; 53–139]

• Can the mechanisms underlying selfless insight really be linked with those that release the covert networks of allocentric intuitive processing? If so, can such links clarify why spontaneous color phenomena could lateralize into the left visual field of an aging meditator?

A plausible sequence of relatively small conceptual steps could be involved. It happens that there are nine such steps in a working hypothesis, condensed elsewhere.³⁰ [MS: 169–177] The way to link them might seem reminiscent of those steps which resolve the standard nine-dot problem. For example, the first stroke follows the course of a diagonal line from the left-lateralized colors that points down toward their sites of origin in the opposite right lower temporal- occipital lobe (see chapter 12). From there, it could take only a small intuitive leap outside the box to realize the creative implications of that arrow line of allocentric processing shown in figure 3.1. Its trajectory leads us to an important realization: remarkable parallel, intuitive capacities are distributed among our temporal and frontal lobe networks. A wealth of connections from here are poised to engage the rest of the brain in further integrated interactions. [SI: 123–188]

For example, the latest controlled study by Luders et al. included 50 long-term meditators.³¹ Their average duration of practice was exceptionally long: 19.8 years. Significant increases in grey matter volume were found in the subiculum and were slightly greater on the right side. This subregion of the hippocampus sends major projections to the mamillary body of the hypothalamus. These messages relay up through the anterior thalamic nucleus to the cingulate gyrus. [ZB: 180–189] This article refers to the episodic memory functions attributed to the subiculum. These are the kinds of remembrances that could be relevant to the mechanisms that enable long-term meditators to cultivate remindfulness. [ZBR: 99–108; SI: 96–97; MS: 109, 162]

New research horizons continue to open up in front of us every day. In no way could tDCS have been foreseen back in eighteenth-century Italy, on that day when Luigi Galvani just happened to see a frog’s leg twitch as it responded to a nearby electrical charge.³² Today’s developments in direct current research appear to have galvanized a fresh view of the future. How will electromagnetic energies next be used, selectively, in techniques that change the resting potentials of inhibitory and excitatory nerve cells inside our brain? How will they be misused? Stay tuned.³³