Consciousness and Neurotheology

Kelly Bulkeley. Science, Religion, and Society: An Encyclopedia of History, Culture, and Controversy. Editor: Arri Eisen & Gary Laderman. Volume 2, M.E. Sharpe, 2006.

Neurotheology is an imperfect, catch-all term for the work of a small but growing cluster of researchers who are exploring the connections between religion and contemporary brain/mind science. The idea that neuroscientists are zeroing in on “the God part of the brain” has spread to the broader public, generating tremendous excitement about the possibility of creating a higher synthesis of religion and science. Although much of the research being done in this area suffers from serious conceptual and methodological flaws, the findings are extremely provocative, and future progress is likely to be rapid.

Two prominent definitions of neurotheology illustrate the problematic nature of the term. In The Humanizing Brain, Ashbrook and Albright speak of neurotheology as the effort to “explore the neural underpinnings of meaning-seeking, of the complex whole and the elegant parts,” while in The Mystical Mind, d’Aquili and Newberg define the term thus: “By neurotheology we mean that we will examine how the mind/brain functions in terms of humankind’s relation to God or ultimate reality.” These are clearly quite different research projects. Ashbrook and Albright want to foreground the distinctively human capacity for symbolic communication, cultural creativity, and meaning-seeking, while d’Aquili and Newberg focus their attention on mystical experiences of radically altered consciousness produced by meditation and prayer. If we are to continue speaking of “neurotheology,” we will have to acknowledge that many different and not entirely compatible approaches are being employed in its name.

Further complicating efforts at definition is the theology side of the term. Buddhism is a resolutely nontheistic tradition, yet much of neurotheology research (in the d’Aquili and Newberg vein) takes Buddhist meditation as the supreme form of religious practice. Nor does the term properly apply to the work of an atheistic materialist like Michael Persinger—it would be perverse to refer to him as a neurotheologian, yet his work is exactly like that of d’Aquili and Newberg in trying to correlate religious experience and brain functioning. A more accurate and inclusive term is clearly needed in this area, but for the moment neurotheology holds linguistic sway.

The common denominator of the various studies conducted under the neurotheology rubric is a desire to reconsider religion, spirituality, and anomalous modes of consciousness in light of the best available empirical knowledge about the brain/mind system. Understood in this way, neurotheology has a long intellectual history, reaching back at least as far as the pioneering psychological investigations of Sigmund Freud, Carl Jung, and William James. Freud began his professional career as a clinical neurologist, and he developed his theory of psychoanalysis on the foundation of what he knew about current scientific research on the brain. Jung was also a trained medical doctor, and throughout his career he looked for ways to connect his archetypal psychology with the latest advances in physical science. And James, in The Varieties of Religious Experience, used recent discoveries from experimental psychology to argue that religious experience is, on its “hither” side, a continuation of the subconscious realm of mental functioning.

A list of even earlier progenitors of neurotheology would have to include Friedrich Nietzsche, the nineteenth-century German philosopher, who sought the psychophysiological bases of religion and morality; Emanuel Swedenborg, the eighteenth-century Swedish scientist and mystic, who offered an elegant system of bodily and spiritual integration; René Descartes, the seventeenth-century philosopher, whose anatomical studies of the brain led him to claim the pineal gland was the seat of the human soul; and reaching back into the Greco-Roman cultural tradition, naturalistic philosophers like Cicero, Lucretius, and Aristotle, who explained seemingly divine dreams, visions, and prophecies as nothing more than the function of natural bodily processes.

Few contemporary researchers in neurotheology show sufficient awareness of their indebtedness to these earlier investigators. To avoid the danger of what Jeremy Carrette calls “disciplinary amnesia,” neurotheology will need to cultivate a greater historical self-understanding and a greater appreciation for the influence of broader social, cultural, political, and economic forces on the study of religion and brain/mind science.

Neurotheological Research Today

What makes neurotheology so exciting today is the use of highly sophisticated and precise technologies to localize, analyze, and measure brain activity. The most important of these technologies are electroencephalography (EEG), which uses electrodes attached to the scalp to measure patterns of electrical activity across the brain; positron emission tomography (PET) and single photon emitting computerized tomography (SPECT), both of which involve a radioactive solution being injected into the bloodstream, which is then tracked to reveal variations in the metabolic activity of the brain; and functional magnetic resonance imaging (fMRI), which also measures regional blood flow in the brain but does so by placing the subject within a very intense fluctuating magnetic field.

Each of these technologies has advantages and disadvantages. The EEG allows subjects to move around and engage in a wide variety of ongoing activities, but it is poor at measuring the activity of deeper brain structures. PET and SPECT scans allow for much more precise measurements than the EEG, but they are invasive procedures, and the time required to develop the images (from a few seconds to minutes) means that rapid changes in brain activity cannot be detected. The fMRI produces by far the clearest and most detailed pictures of the brain, but it requires subjects to remain motionless for long periods of time (thereby limiting their range of activities), and the high-power magnetic fields necessary for producing the images are potentially dangerous if used for more than brief periods of time.

All of these technologies are expensive to operate, and competition is fierce for the monetary grants necessary to make use of them. Researchers who want to use EEG, PET, SPECT, or fMRI devices to study religion are thus compelled to justify their projects to the satisfaction of governmental and institutional funding authorities. This is an important factor to consider in evaluating the directions taken by future research in neurotheology.

What follows are brief synopses of some of the leading studies in neurotheology over the past few years.

Transcendental Meditation

The earliest and most intensely studied subject of neurotheological research has been Transcendental Meditation (TM). Since the early 1970s, hundreds of experimental studies have been performed that investigate the physiological effects of the meditation technique taught by TM’s founder, Maharishi Mahesh Yogi. According to these studies, TM produces a significant drop in respiration, heartbeat, and oxygen consumption. EEG readings show a dramatic shift from the alpha wave activity predominant in quiet restfulness to a much slower pattern of theta waves. In especially deep meditational states, an overlay of faster beta waves emerges. Most intriguingly, some studies have shown that the electrical activity of the brain tends toward synchronization and cross-brain coherence during meditation. EEG monitors tracked the new brain wave patterns (presumably initiated by the concentration of the meditator) as they gradually spread throughout the brain, to the point where the EEG readings from multiple scalp locations showed a uniformity of frequency, amplitude, and wave form.

Relaxation Response

One of the pioneering researchers in the experimental study of TM and meditation more generally is Herbert Benson, who has invented a contemplative technique based on “the relaxation response,” which he claims is an evolutionarily conserved phenomenon analogous to the “fight or flight” response. Benson’s technique involves two components. The first involves a focus on a repeated sound, word, phrase (either silently or aloud), or a muscular activity (e.g., walking, dancing, bowing), or a fixed gaze at a special object (e.g., icon, mandala). The second component is a passive disregard for distracting everyday thoughts and a continual return to one’s focus. Benson and his research colleagues have documented not only the physiological changes that are produced by his technique (decreased metabolism, heart rate, blood pressure, respiratory rate) but also the therapeutic effectiveness of eliciting the relaxation response in people who are suffering from stress, chronic pain, and other health problems. Benson is forthright in his conviction that the technique represents a universal core of mystical experience.

Intercessory Prayer

Dozens of studies have investigated the possibility that one person’s prayer can affect another person’s health. Well-designed and methodologically sound studies on prayer have produced suggestive results. For example, Randolph Byrd found that cardiac patients who received prayer were significantly less likely to develop additional health complications than patients who received no prayer. But skeptics have not yet been persuaded that such results are statistically meaningful. Even the advocates of prayer cannot say with any exactitude how these apparent effects are generated, beyond the obvious fact that the person praying is striving to focus all his or her mental energy on positive thoughts aimed at the patient.

A study of prayer as religious experience was performed by Nina Azari and colleagues at University Hospital Dusseldorf. Twelve subjects from an evangelical church in Germany prayed using the first verse of Psalm 23 while a PET scan was performed on their brains. It was found that the intense prayer experiences activated a frontal-parietal circuit that, according to other studies, is key to our capacity for sustained reflexive evaluation or thought. One important implication is that religious experience need not always involve heightened emotional activation (the limbic region was not unusually active in these subjects), but may engage the “highest” processes of consciousness and self-reflection.


In addition to the prayer studies, a literature has developed on the neuroscientific basis for traditional Christian conceptions of faith, the immortal soul, and God’s action in the world. Ashbrook and Albright’s The Humanizing Brain is the most prominent work from this perspective. It relies heavily on neurophysiologist Paul MacLean’s notion of the “triune brain,” by which the structural evolution of the human brain is seen to consist of a “reptilian” behavioral core (the brain stem), a “mammalian” middle region for emotions, memory, and sociability (the limbic system), and the “human” outer region (the prefrontal cortex) that allows us to concentrate, plan, and make volitional decisions.

At each level of neural organization, Ashbrook and Albright see correlations between brain/mind functioning and trinitarian Christian doctrine. Thus the brain stem’s role in basic bodily functioning and psychophysiological homeostasis is said to reflect the numerous biblical portrayals of God as “territorial, hierarchical, watchful, persistent, unchanging,” with the deceptive serpent of Genesis 3 serving as an apt image of the reptilian brain’s tendency toward selfish cunning and sudden aggression. The limbic system provides the emotional basis for social relatedness and the formation of communities, and Ashbrook and Albright take this as neurobiological evidence in support of God’s benevolent action in endowing us with a divine capacity to love our neighbors. Research on the neocortex, with its capacity for complex and purposeful cognitive processing, is in their view not only compatible with but actually enhances the traditional Christian theological portrait of God: “We propose that the God of this universe is complexifying, interactivedynamic, and loving, and that the combination of these characteristics indicates a God who is purposeful.”

It should be noted that MacLean’s theory is but one of many vying for conceptual dominance, and neuroscientists like Joseph LeDoux have explicitly rejected the triune brain model as overly simplistic and misleading.

Buddhist Meditation

The most dynamic area of current neurotheology research revolves around various types of Buddhist meditation. A pioneer in this area is James Austin, who wrote Zen and the Brain (1998). Austin is a longtime practitioner of Zen Buddhist meditation, and he attributes the passion of his research interests to a sudden, surprising moment of revelation in a London subway station: “Time was not present. I had a sense of eternity. My old yearnings, loathings, fear of death and insinuations of selfhood vanished. I had been graced by a comprehension of the ultimate nature of things.” Austin took this wonderful experience as the inspiration to use his neuroscience training to investigate the neural processes underlying moments of enlightenment like his own. He says such experiences involve diminished activity in the limbic system, particularly the fear-detection circuits of the amygdala; diminished activity in the parietal lobe areas responsible for orientation in space and self-world distinction; and diminished activity in the prefrontal systems involved in the executive functions of ordinary conscious awareness.

The capacity for mystical experiences is an essential feature of being human, according to Austin, and he presents his work as a new scientific advance on earlier theories of religious experience. “Aldous Huxley called mankind’s basic trend toward spiritual growth the ‘perennial philosophy.’ Herein, I take a different perspective. To me, the trend implies a dynamic, intimate perennial psychophysiology. It is a series of processes, slowly evolving, that culminate in defining moments of an extraordinary character.”

Several other studies involving Buddhist meditation should be mentioned. Richard Davidson at the University of Wisconsin conscripted a group of employees from a nearby biotechnology company called Promega and had twenty-five of them participate in an eight-week training in mindfulness meditation. At the end of the eight weeks, he used EEGs to compare the activation patterns of the twenty-five meditators and those of sixteen Promega employees who did not receive the training. The meditators showed greater activation in the left anterior region of the prefrontal cortex, a region associated with positive emotional states. Davidson also tested the immune systems of both groups and discovered that the meditators developed significantly more antibodies in response to a shot of flu vaccine than did the control group. Furthermore, the meditators who demonstrated the greatest increase in left-side brain activation also produced the strongest immunological response.

Newberg and d’Aquili used the resources of the radiology laboratory at the University of Pennsylvania to do SPECT scans of the brains of Buddhist meditators and Franciscan nuns in prayer. They found that during states of intense meditation and prayer, the areas of the brain responsible for sensory perception and orientation essentially shut down due to a lack of meaningful input, while the prefrontal executive regions responsible for the abilities “to concentrate, plan future behavior, and carry out complex perceptual tasks” become highly activated. In such a neurological condition, lacking any of the information normally used to define self and world and yet highly aroused and attentive, the brain interprets its experience as suddenly devoid of boundaries: “The brain would have no choice but to perceive that the self is endless and intimately interwoven with everyone and everything the mind senses. And this perception would feel utterly and unquestionably real. This is exactly how [our subject] Robert and generations of Eastern mystics before him have described their peak meditative, spiritual, and mystical moments.”

Yogic Practice

Hans Lou and colleagues at the Kennedy Institute in Denmark used PET scans to study the brain functioning of a group of highly experienced yoga teachers during a relaxation meditation called yoga nidra. The meditation involved listening to an audiotape providing forty-five minutes of guided imagery, with the subjects attending sequentially to their bodies, abstract joy, visualization of a beautiful nature scene, and visualization of an abstract perception of the self as a golden egg. The PET scans revealed heightened activation in exactly those brain systems corresponding to the guided imagery tasks: the supplementary motor area responsible for bodily planning and attention was activated during meditation on the weight of the limbs; the left hemisphere (including Wernicke’s region, responsible for spoken words) was activated during the abstract meditation on the word joy; the regions of the posterior cortex involved in voluntary visual imagery were activated during the nature visualization; and parietal lobe regions in both hemispheres responsible for bodily representation were activated during the meditation on the self. Of particular significance, the subjects’ brains showed a selective deactivation of those pre-frontal regions involved in the executive functions of volition, selective attention, and goal-oriented action. In this regard, the yoga nidra practice resembles REM sleep in diminishing the activity of the prefrontal executive system and stimulating the activity of the posterior visual system.

A study by Sara W. Lazar and colleagues at Harvard Medical School used the fMRI technique to study the brain activation patterns of a group of subjects who had practiced Kundalini meditation daily for at least four years. The Kundalini technique is similar to the relaxation response approach (Herbert Benson is one of Lazar’s colleagues) insofar as it involves close attention to one’s breathing, silent recitation of a mantra, and a passive attitude toward intruding thoughts and feelings. It was found that this meditational technique “activates neural structures involved in attention (frontal and parietal cortex) and arousal/autonomic control (pregenual anterior cingulated, amygdala, mid-brain, and hypothalamus).” Lazar and colleagues further discovered that this distinctive pattern of neural activation became more pronounced the longer the meditation went on: “These findings suggest that neural activity during meditation is dynamic, slowly evolving during practice.”

Prospects for the Future

As this review of current research suggests, the findings of neurotheology do not fit into any neat theoretical framework. Different types of religious and spiritual practice are correlated with different patterns of brain activity. Based on the evidence gathered so far, there is no one pure, ultimate, absolute form of mystical experience, but rather a colorful variety of extraordinary states of brain-mind functioning. This means that neurotheology cannot continue to grow as a field if it uses a universalistic, “one size fits all” approach to religion. Rather, a pluralistic approach is needed that can recognize broad similarities and unique differences in religious experience.

Neurotheology will need to overcome several other obstacles if it is to prosper in the future, including the distorting influence of the lab effect, the limiting focus on Christianity and Buddhism (for a healthy corrective, see Ramachandran and Blakeslee’s Phantoms in the Brain), the privileging of meditation and prayer as the supreme forms of religious practice, the instrumental attitude that useful techniques for modern stress reduction can simply be extracted from religious traditions, and as mentioned earlier, the danger of a disciplinary amnesia that ignores, neglects, or represses the historical context in which present-day neurotheology is conducted (for further discussion see my The Evolution of Wonder). Should researchers succeed in meeting these admittedly formidable conceptual and methodological challenges, the prospects for neurotheology—or whatever new name we one day decide to call it—are bright indeed.