Biology 202

2006 First Web Paper

On Serendip

With the development of new brain imaging technology, scientists began to be interested in the neurobiological underpinnings of mystical experiences. Dr. V. S. Ramachandran, a neuropsychologist at the University of California San Diego, focuses on temporal lobe epilepsy (TLE) patients, who are prone to excessive activity in their temporal lobes. TLE patients experience micro-seizures, which result in powerful and deeply emotional religious experiences. What is more, the effect of these seizures is not fleeting: most TLE patients are religious during the periods between the seizures, sometimes to the point of fanaticism. Dr. Ramachandran and his colleagues proposed that heightened electrical activity during these seizures strengthens connections between the subject's temporal lobe sensory areas and the amygdala (a brain region usually associated with emotion), resulting in the patients' intensely personal and emotional reaction to their experiences. With the help of skin conductance response (measuring small rapid changes in perspiration), Ramachandran investigated whether TLE patients would have a stronger emotional response to sexual/violent stimuli or to the stimuli with religious nature. His subjects, indeed, showed heightened arousal when presented with religious words and symbols. In contrast, control subjects displayed the strongest responses to sexual stimuli. Dr. Ramachandran's findings, however, were inconclusive, due to the limited number of test subjects and to the fact that TLE patients often have changes in sexuality. Nevertheless, his studies suggest that the temporal lobe is involved in religious experiences and, according to Ramachandran's 1997 presentation at the conference of the Society for Neuroscience, that individual neural differences in that area may influence the degree of personal religiosity in healthy people. (1)

Some neuroscientists search for a particular neural module, responsible for processing, and perhaps producing, religious experiences. They are also interested in the degree to which this "God-module" is genetically determined and in its significance in the evolution of the human brain. Dr. Michael Persinger of Laurentian University in Canada, like Ramachandran, suggests that activity in the temporal lobe is the neurological basis of spiritual experiences. Unlike his colleague, he works with healthy adults - religious, agnostic, and atheistic. Over the years, he developed what has been dubbed "Persinger's helmet," literally a yellow motorcycle helmet equipped with solenoids, emitting weak electro-magnetic fields (4) and capable of producing "micro-seizures" in the temporal lobes, akin to the seizures in TLE patients (1). These micro-seizures, or "temporal lobe transients" (TLT), are "short-lived rate increases and instability in the firing patterns of neurons in the temporal lobe" (1). During the experiments, the subjects are placed on a recliner in a sound-proof dark chamber, which is designed to minimize sensory input (4). Impulses directed at the subcortical (limbic) areas in the temporal lobe produce distortion of body image, forced motion, and strong emotion. When temporal cortical areas are targeted, subjects report dreamlike visions, a "sense of presence," and strong emotions. According to Persinger, the visions are easily influenced by particular religious suggestions - a view of a crucifix prior to the study or playing Eastern music during the experiment (3). Some subjects report a pleasant experience, while others exhibit a sharply negative emotional response: their heart rate goes up; they cut the experiment short because of intense fear and even "struggle to take off the electrodes" (4).

Persinger's explanation of the "sensed presence" denies any external influence. According to him, the process leading to this experience can be described as follows. The activity of the neural systems in our left hemisphere temporal cortex mediates our sense of self. This activity is normally matched by the neural activity in the corresponding parts of the right hemisphere temporal cortex. During TLT events, these patterns of activity are mismatched, and the left hemisphere (also associated with language) interprets the discord as "another self" or a "sensed presence," whether divine or demonic. Excessive stimulation of the subcortical areas in the temporal lobe, particularly of the amygdala (the seat of emotion) and of the hippocampus (associated with autobiographical memory) lends personal and deeply emotional character to the experience (3). Persinger, who has tested more than 900 subjects, says that the intensity of one's response depends on individual lability, or sensitivity to TLT events (4). On the one hand, this sensitivity is natural (across healthy subjects, some show a tendency for TLT events even in the absence of Persinger's helmet) (3). On the other, it is itself a fluctuating condition: TLT events may be triggered without the helmet by anxiety, personal crisis, lack of oxygen, low blood sugar, and even fatigue (3).

It is interesting that the subjects give different names to the "presence of another" that they felt during the study. These names are usually appropriate to their religious beliefs, upbringing, or knowledge, but some identify that "other" as a parent or relative, or report childhood memories, with or without spiritual content. Moreover, still others insist that the presence was demonic, or describe the experience in terms of the UFO abduction stories (4).

When discussing the implications of his findings, Persinger denies the "God module" theory. Instead, he proposes that the brain areas that mediate our sense of self, general emotion, and autobiographical memory also participate in religious experiences. Although his studies do not specifically address the question of genetic innateness, Persinger believes that "the god experience" has survival value, since it allows humans to overcome their anxiety and the fear of death by connecting to something that is perceived as both eternal and outside oneself (2).

Unlike Persinger, Dr. Andrew Newberg of the University of Pennsylvania does not strive to produce "the god experience." Instead, his research focuses on mapping the brain activity of religious subjects at the highest points of prayer and meditation, particularly in Tibetan Buddhists and Franciscan nuns. First, a baseline scan of the subject's brain is taken in order to obtain a picture of his or her normal neurological activity (5). The subjects are then placed in a room, where they are allowed to create an environment appropriate for the reaching of high mystical states. They then go through their usual routines, such as quieting their conscious mind and allowing their "true self" to emerge (for Buddhists) or repeating prayers and allowing oneself to open to God (for the nuns). When the subject reaches the highest point of his or her experience, he or she pulls on a string, signaling readiness to Dr. Newberg. The scientist then injects a radioactive tracer into an IV line in the subject's arm and places him or her into the SPECT (single photon emission computed tomography) machine. The tracer allows Newberg to locate and take a picture of the areas of the brain with the highest blood flow, which correlate with neuronal activity. (3)

As expected, the images show heightened activity in the prefrontal cortex, associated with attention, which correlates with the subjects' concentration. A bundle of neurons in the superior parietal lobe, which is often called "orientation association area" (OAA) and which mediates our orientation in space and time and creates the boundary between our self and the outside world, however, shows an unusually low activity. Normally, the activity in the OAA area is consistent, allowing us to reliably navigate through space and to tell time. Dr. Newberg suggests that the OAA continues to work, but that the subjects somehow block the sensory input to this area during meditation or prayer. This process, known as deafferentation (a neural structure is cut off from sensory inputs or afferents), results in perceiving oneself as endless and connected with the rest of the world (5). This is in agreement with the subjects' reports on their feelings of oneness with the universe (for the Buddhists) and with God (for the nuns). The usual dualistic split between "I" and "the world" and the reality of time disappear. (3)

It is noteworthy that, although both the Buddhist meditators and the Catholic nuns report experiencing unitary states (and exhibit similar patterns of neural activity), there are differences between their SPECT scans. The nuns' vehicle to reaching peak spiritual states was the Centering Prayer, involving repetitions of words. Appropriately, their right inferior parietal lobe, associated with evaluating the emotional weight and inflection of words and phrases, showed increased activity. This pattern was not observed in the Buddhists, whose normal practices include emptying of the mind of any conscious thought. These correlations confirm the reliability of Dr. Newberg's findings. (5)

Like Persinger, Newberg believes that spiritual experiences, which include emotions, thoughts, sensations, and behaviors, are too complex to be mediated by a particular "God module" within the brain. Instead, the activity is distributed throughout, involving the arousal and quiescent systems, the limbic system, the hypothalamus, the amygdala, and the hippocampus. He suggests that "the human brain has been genetically wired to encourage religious belief," and that this "machinery of transcendence may have arisen from the neural circuitry that evolved for mating and sexual experience" (5). He also proposes that the ability of the brain to mediate spiritual experience has a survival value, increasing human physical and psychological health and well-being. Moreover, he believes that mystical practices may be able to positively alter human behavior. (5)

While he insists that the mystical experiences are events mediated by the brain, Newberg does not wish to undermine their religious validity or even outside reality. For centuries, rational human beings (at least in the Western tradition) accepted the reality of the everyday world, of the objective universe existing independently of us. However, the human condition is such that we cannot have an absolute, direct experience of this reality. Everything we do or see, from the taste of an apple pie to a beautiful sunset, is mediated and processed by our brain. We cannot know (and science cannot tell us) whether there is, in fact, a world out there or whether our brains - immense and complicated systems that can not only process, but also generate signals - simply make it up. Of course, Newberg agrees that our shared realism is a good working hypothesis and that, in fact, we all rely on the deep conviction (one might even call it a belief) that the chairs we sit on or the people we talk to are real. But he points out that mystics par excellence, as well as ordinary believers and even unbelievers who have had a mystical experience, also have this conviction of the reality of their visions. What is more, they often insist that these experiences were "more real than reality itself." Therefore, just as we cannot dismiss the objective reality of the apple pie solely on the basis of the fact that we can make a scan of the brain's "apple pie experience," we cannot treat the neurobiological data of mystical states as the conclusive proof of God's non-existence. (6)

Such a view certainly shows that modern "neurotheology" does not necessarily debunk theology proper. On the contrary, current studies may be even consistent with some theological dogmas that for centuries were taken on faith alone. For instance, if one believes in the soul intimately connected to the body, one can now see the physical changes their coexistence produces in the brain. Similarly, now we can understand how it is possible for the dualistic time and space distinctions to disappear during meditation or prayer- something that could not be explained before. Moreover, science itself reaffirmed the central postulate of any faith: God's existence or non-existence cannot be proved, it must be experienced and believed in.

Current research also calls for new, more rigorous, inquiry into the neurobiology of spiritual experiences. For instance, most researchers operate under an assumption that all mystical experiences are similar and that the names and symbols attached to them are merely cultural creations. Even some religious writers, for instance, Rich Heffern of the National Catholic Reporter, claim that throughout the history of religion we can find "the same generic description, couched in the language of [a] particular culture and tradition - a description of unitary states" (5). But this assumption fails to take into account the fine distinction between the unitary states experienced by Buddhists as opposed to, for example, Christians. While Buddhist meditators strive towards and sometimes achieve a feeling of oneness with the universe, of the disappearance of self, and of non-existence par excellence, Christian mystics insist that God is personal, that an encounter with Him will have the features of both unity and separateness. The biological correlate of this distinction remains to be found.

Moreover, scientists should take into consideration the fact that mystical teachers and practitioners throughout the world warned their students of "false" and "true" experiences. When Persinger describes how the brain can create a presence of another self, he does not realize that he restates a warning given by theologians - do not make up a god in your head, strive to encounter a real one - in neurobiological terms. Spiritual discipline and asceticism that allowed mystics to differentiate between genuine and false experiences are difficult to acquire, but it would be interesting (if, perhaps, impossible) to trace the neurobiological differences that distinguish the two. Also, neurobiologists need to realize that it is manifestly not the same thing for believers to feel a demonic presence, a divine presence, or to have a "visit" from one's father or an alien. Persinger, who seems to place these distinct experiences into one model, may need to refine both his methods and his style of data analysis. Other interesting questions not addressed in the current studies are the long-term effect of spiritual experiences on the brain and the fact that many people are believers without ever having an encounter on the scale of Newberg's subjects.

While neurobiologists may want to brush up on theology, theologians should familiarize themselves with the progress of science. Neurotheology has a direct bearing on mysticism, dogmatic theology, ecumenism, and religious evolutionism. The religious community should cease regarding science as an enemy, now that the scientists themselves acknowledge their inability to prove or disprove the existence of God. Collaboration of theology and neurobiology may lead not only to important theoretical findings, but also help improve human psychological and physical health. There are only two things that neither systematic theology nor neurobiology will ever be able to prove or to explain: first, the existence of God and, second, the experience of God's call directed to the individual person, a call that can happen in the midst of the everyday bustle or of the most rational and skeptical human activity. A sudden and unwaited-for call that we cannot ourselves reach through meditation or prayer and that, therefore, may never be registered and captured by the most advanced technology.

Web Resources

1)"Searching for God in the Machine", an article on neurotheology from the Summer 1998 issue of Free Inquiry; also available through Tripod.

2)"Religion and the Brain", transcript of a PBS broadcast on November 9, 2001.

3)"Religion and the Brain", article on neurotheology in the May 7, 2001 issue of Newsweek; also available through Tripod.

4)"This Is Your Brain on God", an article on Persinger's experiments by one of his subjects.

5)"Exploring the Biology of Religious Experience", an article on neurotheology and faith by a believer.

6)"Brain Science and The Biology of Belief, Part 3", one of the series of articles by Dr. Andrew Newberg on the Metanexus Institute site.

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