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Exploring the biology of religious experience

NCR Staff

Those who deeply and regularly pray report that when praying they feel at one with the universe, unafraid of death and in awe of the Mystery they connect with. Scientists have connected some of these people to instruments that peer into the enchanted loom that is their brain, tracing the weaving, flashing shuttles of their neural connections. They seek understanding of the physical dynamics beneath those beatific experiences. They are probing the biology of religion.

Studies have been conducted by scientists in Canada, Britain and the United States. A key researcher in the United States is Andrew Newberg, a physician and fellow of the Division of Nuclear Medicine at the hospital of the University of Pennsylvania Medical School, in Philadelphia. Newberg worked closely with Eugene d’Aquili, a professor of psychiatry at the hospital, who died in 1998. D’Aquili began doing neurological studies of religion more than 25 years ago. Newberg began his association with d’Aquili 10 years ago.

Their research suggests that religion is intimately interwoven with human biology, that the brain’s structure, in fact, compels the spiritual urge and that the brain has the capacity to make spiritual experience real. They use the term neurotheology. Their findings suggest religion and spirituality had an evolutionary function.

D’Aquili and Newberg first published their research and findings in scientific journals, then in a book titled The Mystical Mind: Probing the Biology of Religious Experience, published in 1999 by Fortress Press, a Lutheran publisher. Their new book, Why God Won’t Go Away: Brain Science and the Biology of Belief, was released by Ballantine Books on April 3. This new book is a more popular reworking and update of their research.

In their empirical work, these researchers constructed a model of what happens in the brain during significant spiritual experiences by peering into the gray matter of praying Franciscan nuns and meditating Tibetan monks using what is known as single positron emission computed tomography (SPECT). Conclusions based on their laboratory findings and on what is already known about brain function reveal surprising insights into the biological basis of spirituality.

Activation studies using image-scanning techniques have given us a detailed picture of functions of the individual structures of the brain, according to Newberg. We know which areas of the brain are associated with the five senses, which are activated by motor behaviors, from jogging to making high-fives. Scientists watch various parts of the brain turn on and off as subjects do algebra, write verse or feel a cramp. More information comes from studying patients with injuries or tumors in various areas.

Neurobiological research, though, has largely bypassed religious experiences and beliefs except that done by a handful of scientists.

Until the 1970s, religious experience and activity were believed to be purely cultural phenomena, a product of social conditioning, and not in any way biological. Little effort was made to investigate the physiological aspects of, say, ritual or chant. Thanks to the work of d’Aquili, Newberg and their colleagues, the biological side is becoming an important component in the study of human religious experience.

“Spiritual experiences are the inevitable outcome of brain wiring,” said Newberg. “We believe that the human brain has been genetically wired to encourage religious beliefs.”

The two scientists have identified areas of the brain that work together to provide the network that underlies religious activities like prayer, meditation or ritual. They have found evidence that, for example, liturgy has an evolutionary survival value (see sidebar, page 16). The capacity for mystical experience, they theorize, is a byproduct of sexual development in the human. They think that the religious experiences people near death commonly report have a neurological basis.

Religious and spiritual experiences are typically highly complex, involving emotions, thoughts, sensations and behaviors. These experiences seem far too rich and diverse to derive solely from one part of the brain, according to Newberg. It is more likely that many parts of the brain are involved. They have evidence that both the arousal and quiescent systems, the most basic parts of the body’s nervous system, are involved in religious activity. Also, the limbic system, the old part of the brain that controls and conveys emotions, seems to be a key player. Other brain organs like the hypothalamus, amygdala and hippocampus participate, too.

Newberg and d’Aquili point out that as soon as the human brain became sufficiently complex in structure, mind took shape, consciousness sparked into being. They use the terms “mind” and “brain” in the same way physicists talk of light in terms of wave and particle, two ways of looking at the same thing.

Andrew Newberg was raised in the Jewish tradition; Eugene d’Aquili came from the Catholic one. Newberg told NCR that his colleague and friend loved to go to Mass, that his avid interest in religious liturgy and practice certainly stemmed from this heritage. D’Aquili held a doctorate in anthropology. They met when Newberg was a medical student; the combination of d’Aquili’s interests and Newberg’s background in brain imaging allowed the two to move forward in research.

Hooked up to prayer

Their lab work involved brain scans of experienced Tibetan Buddhist meditators and Franciscan nuns seasoned in prayer. The investigative technique they use is fairly simple, starting with a baseline scan of the subject’s brain state at rest. They then hook her up to a long intravenous line. A simple string tied to a finger allows the subject to signal to the doctors when she has entered the deepest stages of her prayer. At that signal they inject a radioactive dye into the line, wait for the prayer to finish, then trot the subject off to the SPECT camera waiting in the Nuclear Medicine Department.

The camera detects radioactive emissions. The injected tracer locks almost immediately into brain cells and stays there for hours, so they soon have an image of blood flow patterns as they occurred just moments after the injection. Increased blood flow to a part of the brain correlates directly with heightened activity. Since neuroscience has a good idea of the specific functions performed by brain regions, the SPECT images reveal what the brain was doing at the moment of injection.

Finished images (see photos) showed increased activity in the frontal lobes, the attention area, and decreased activity in the posterior superior parietal lobe. Biologists know that this latter area of the brain primarily orients us in space, keeping track of which way is up or down, forward or behind, and helping us judge distances and angles. Structures in this part of the brain combine to form the orientation association area (OAA), which must constantly generate a clear, consistent awareness of the physical limits of the self in order for us to function without looking like Buster Keaton, always stumbling and collapsing.

It’s the mind’s way of telling us the difference between us and everything else, and it’s a function that must work all the time flawlessly so we can get around. People who suffer injuries in this area have difficulty maneuvering in space; they are unable to even get into bed or lie down once there.

The increased activity in the attention area was expected, since meditation tends to focus the brain. Scientists know however that the OAA never rests, according to Newberg, so what would cause the drop in activity in an essential function area of the brain?

“What if the area was working as hard as ever, but somehow the act of meditating had blocked its flow of sensory input? We were fascinated by this possibility,” said Newberg. Does meditation “blind” the OAA deliberately? And if the OAA has no information upon which to work, what would the brain make of it?

Newberg and d’Aquili write: “Would the orientation area interpret its failure to find the borderline between the self and the outside world to mean that such a distinction doesn’t exist? In that case 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 the empirical subjects and generations of people of prayer before them have described their peak mystical moments: the dissolving of boundaries between the self and everything else. A 13th-century Franciscan Angela of Foligno expressed it this way: “I possessed God so fully that I was no longer in my previous customary state but was led to find a peace in which I was united with God and was content with everything.” Consult manuals of Zen meditation, texts from Hindus, Sufis or Christian desert fathers on prayer and you will find the same generic description, couched in the language of that particular culture and tradition -- a description of unitary states.

Newberg and d’Aquili believe that the neurological phenomenon known as deafferentation, when a brain structure is cut off from sensory input (afferents), is responsible for the experience of a unitary state.

Newberg told NCR that there were differences found between the scans of the Franciscans and those of the Tibetans. The sisters had been doing Centering Prayer, which traditionally involves the interior repetition of a Christian phrase or mantra, which leaves the praying person open to experiencing God’s presence. Their SPECT scans showed activity in the right inferior parietal lobe, a part of the brain known to be involved in evaluating the emotional weight and inflection of words, phrases. Someone with damage in that area would not be able to evaluate, for example, the phrase, “Get out of here!” as either a rejecting command or a slang phrase for disbelief. The same deafferentation of the orientation area was observed as well. “It’s interesting that the nuns’ prayer, which was more involved with words, showed activation in the brain’s word areas,” Newberg said. Such findings reinforce the validity of the study.

The machinery of transcendence

“The overcoming of the barriers between the individual and the Absolute is the great mystical achievement,” wrote William James more than 100 years ago. Once revered as sages and seers in ancient and medieval societies, mystics fell on hard times in the age of rationality, often being considered as delusional or disordered. That is changing as a result of the recent interest in all things spiritual.

We now know the health benefits of spirituality. Significant research shows that people who pray on a regular basis enjoy higher levels of psychological health than the public at large, according to Newberg. Meditation, for example, lowers blood pressure, heart rate and decreases anxiety and depression. Ironically, the American Psychiatric Association listed “strong religious belief” as a disorder in their diagnostic manual as late as 1974.

From relaxing in a tub after a hard day to the most profound prayer, the brain’s complex functions, evolved over millions of years, make possible this continuum of unitary states that culminate in the deepest religious experiences. Throughout human prehistory and history, write Newberg and d’Aquili, mystical techniques were intuitively devised by shamans, saints, gurus, dervishes and spiritual masters -- ways like prayer, chanting, meditation or ritual -- to trigger the process of deafferentation, leading to various degrees of unitary states, in turn perpetuating human spirituality.

What evolutionary advantage do mystical states bring to human development?

“We suspect all this did not evolve initially for spiritual purposes. Evolution doesn’t plan ahead,” said Newberg. Instead intermediate steps evolve for their own reasons, like nubbins on small reptiles in the Cretaceous era that made for better temperature control, then gradually elongated into more complex webbing that made gliding possible, then full-fledged wings that could be used for the first animal flight.

“We believe the neurological machinery of transcendence may have arisen from the neural circuitry that evolved for mating and sexual experience,” said Newberg. Mystics use terms like bliss, rapture, ecstasy, exaltation. It’s no accident that this is also the language of sexual arousal, Newberg and d’Aquili write. Scientists think the quiescent and limbic systems evolved partly to link sexual activity to the pleasurable experience of orgasm, with obvious evolutionary benefits. Components of the limbic system are involved in the deafferentation process. Psychologists have long known that play and social activity are not just related to socialization but also influence development of the brain. Sex and prayer are obviously not the same experience, said Newberg. Neurologically they are quite different, but “mystical prayer and sexual bliss use similar neural pathways.”

There is a hopeful quality to their research, according to Newberg, since mystical practice may be the best way to change human behavior for the better in the long run. “Consider that domination, greed, cruelty, violence and all our other ills arise from an insufficient and insecure being,” writes Beatrice Bruteau, an expert on Eastern mysticism quoted in their new book. Newberg adds that their work also sheds light on the problem of religious intolerance. “Incomplete unitary states might leave a person feeling hostile to anyone who contradicts their vividly real experience of oneness with God the Father, Allah or Jesus.”

The origins of theology

Everything that happens to us or any action we take can be associated with activity in one or more specific regions of the brain. This includes necessarily all religious and spiritual activity and experiences. The only place God can manifest God’s existence is in the tangled neural pathways and physiological structures of the brain.

The Word must be made electrochemical to spark across the synapses and travel our fleshy nerve pathways.

Religion persists because brain wiring continues to provide us with a range of unitary experiences that are often interpreted as assurances that God exists, write Newberg and d’Aquili. Although it’s unlikely that the machineries of transcendence evolved specifically for spiritual reasons, it seems obvious now that evolution has picked up on these dynamics and favored the religious brain, they write, because religious behaviors are good for us.

From the brain’s perspective, religion is a wonderful tool and will be around for a long time to come. “But we’re not saying that’s all religion is,” Newberg said, just a trick biology plays on us to keep us healthy. They are suggesting that the neurological basis for religion can be considered from the biological or evolutionary perspective, or from others. It’s also probable that the brain structures and functions that allow spirituality to happen are also ways to connect us with something real beyond the brain.

These are questions for the new field of neurotheology.

What are the implications for theology of studying religion as a neurophysiological phenomenon? Scholars like Rudolf Otto, Mircea Eliade, Joseph Campbell and Carl Jung devoted themselves to the study of the phenomenology of religion, advancing our knowledge in significant ways. This new research puts a biological foundation under them, Newberg said.

Theology is a reasoned analysis applied to religious experiences and beliefs. It’s important to consider the functioning of the brain in considering how we experience God. Newberg says that biology helps explain why theology exists in the first place.

Newberg and d’Aquili’s work suggests that the complexity of the human brain, with its billions of neural connections, a complexity that developed to enable us to survive in hard and hostile environments like those of the Ice Ages, drove, and still drive, us to, for example, find out what causes what. In order to get by in a difficult world, Newberg and d’Aquili theorize that the brain early on developed what they call a causal operator -- a combination of brain and mind functions working together -- that must continually search for and determine why this or that is happening.

For example, that causal operator lets us be aware our fingers hurt because we handled that hot coal. Research shows that this causal operator is a function of the left association area and the left parietal lobe in the brain working together. People who have strokes or tumors in brain areas that contribute to the causal operator can’t determine why something happened.

The causal operator never had an off switch, write Newberg and d’Aquili. Maybe between hunts hundreds of thousands of years ago, a few of our theologically inclined ancestors kicked back, relaxed and used their brains’ causal operator in more abstract ways. Their musings eventually would take causality back, says Newberg, until their minds stumbled up against the notion of the uncaused cause.

The brain’s causal operator has probably always driven us to speculate about why we are here, what the purpose of the universe is, write Newberg and d’Aquili. This function of the brain is genetically hardwired into all of us. Also, the human brain, as soon as it was complex enough to develop a self-aware mind, discovered death. Newberg and d’Aquili theorize that the existential anxiety associated with knowing about death drove us to invent myth-making ability and the capacity for ritual.

Religion is partly the coinage of our unquiet thoughts. Early in human development, it seems, our big brains cornered us into becoming liturgists, religious storytellers and, of course, theologians.

In February 2001, Bishop Elio Sgreccia, vice president of the Pontifical Academy for Life, the Vatican’s leading expert on bioethical issues and medical research, responding to a news report on Newberg and d’Aquili’s work, said: “You can’t say it’s the brain that causes prayer. That would be confusing the effect with the cause.” As for the idea that the feeling of being in God’s presence might simply be the result of the brain’s activity, Sgreccia said that indicated “a mistaken, materialistic view of human actions.”

Newberg responded: “One can look at our findings and interpret them in a reductionist way, of course, and many of our critics do. Yet we’re not simply saying that the brain creates God, rather that the brain has quite naturally developed the mechanisms for religious experiences.

“Is religion, in other words, merely a product of biology -- a neurological illusion -- or does the fact that our brains function in such a curious way argue that God is not only real but reachable?”

What if biology has laid down neural paving stones leading to God?

In their new book, Newberg and d’Aquili quote biologist Edwin Chargaff, who thinks all real scientists are driven by the mysterious intuition that something immense and unknowable dwells in the material world. “If [a scientist] has not experienced,” wrote Chargaff, “at least a few times, this cold shudder down the spine, this confrontation with an immense, invisible face whose breath moves him to tears, then he is not a scientist.”

The shrewd honesty that is the scientific method hints that in part God may be an emergent presence, seeking to be known, within our own bodies, those same bodies so denigrated by the old dualistic religious view that severed spirit from matter.

Scientist, nun, monk or layperson, we all have brains capable of feeling those shudders and flesh on which can be raised the goose bumps of awe. Humans, it seems, are literally made for contemplation.

Rich Heffern’s e-mail address is rheffern@natcath.org

National Catholic Reporter, April 20, 2001