Believers from every tradition and around the world have reported similar sensations of religious experience — a feeling of completeness, absence of self, or oneness with the universe, feelings of peace, freedom from fear, ecstatic joy, visions of a Supreme Being.
With the aid of new technology that allows them to watch the brain in action, a group of scientists — sometimes described as "neurotheologists" — have tried to explain how such experiences occur and perhaps even why.
"There are certain [brain] patterns that can be generated experimentally that will generate the sense, presence and the feeling of God-like experiences," says professor of Neuroscience Michael Persinger of Ontario's Laurentia University. "The patterns we use are complex but they imitate what the brain does normally."
Persinger originally set out to explore the nature of creativity and sense of self. But his research into patterns of brain activity led him to delve into the nature of mystical experiences as well.
To do this Persinger puts his subjects in a quiet room, depriving them of light and sound, so that the nerve cells typically involved in seeing and hearing are not stimulated. Then he applies a magnetic field pattern over the right hemisphere of the brain.
Persinger was asked if his work leads him to conclude that "God," or the experience of God, is solely the creation of brain-wave activity.
"My point of view is, 'Let's measure it.' Let's keep an open mind and realize maybe there is no God; maybe there might be," says Persinger. "We're not going to answer it by arguments — we're going to answer it by measurement and understanding the areas of the brain that generate the experience and the patterns that experimentally produce it in the laboratory."
Mind, Body and Belief
To others who have thought deeply about religion, that is a conclusion that far outstrips the evidence — a scientific leap of faith, if you will.
"They have isolated one small aspect of religious experience and they are identifying that with the whole of religion," says John Haught, professor of theology at Georgetown University.
Religion "is not all meditative bliss. It also involves moments when you feel abandoned by God," says Haught. "It involves commitments and suffering and struggle.… Religion is visiting widows and orphans; it is symbolism and myth and story and much richer things."
Persinger says he is less concerned with trying to prove or disprove the existence of God than with understanding and documenting the experience. However, in his view, "if we have to draw conclusions now, based upon the data, the answer would be more on the fact that there is no deity."
He is clear about an underlying motivation of his work — a fear that unscrupulous people might use techniques to provoke a spiritual experience to control people.
But Persinger also acknowledges a more positive possibility: "If you look at the spontaneous cases of people who have God experiences and conversions, their health improves," he says. "So if we can understand the patterns of activity that generate this experience, we may also be able to understand how to have the brain — and hence the body — cure itself."
What Prayer Does
That search for the mind-body connection also motivates the work of other researchers, such as Professor Andrew Newberg at the University of Pennsylvania.
"Whether there is a God or not in some senses isn't as relevant to the kind of research we're doing so much as understanding why those feelings and experiences are important to us as human beings," he says.
Newberg observed the brains of Tibetan Buddhists and Franciscan nuns as they engaged in deep prayer and mediation by injecting radioactive dye, or "tracer" as the subject entered a deep meditative state, then photographing the results with a high tech imaging camera. He found that "when people meditate they have significantly increased activity in the frontal area — the attention area of the brain — and decreased activity in that orientation part of the brain."
Many of these changes occur whether people are praying (focusing on oneness with a deity) or meditating (focusing on oneness with the universe). But there are differences, in that prayer activates the "language center" in the brain, while the "visual center" is engaged by meditation.
Either way, Newberg finds that the sense of "unity," or "oneness" experienced by his subjects is a real, biological event. And he acknowledges the limits of his own work: He currently lacks a means to measure the neurological events associated with other religious practices — such as caring for the poor or ecstatic worship.
"Our work really points to the fact that these are very complex kinds of feelings and experiences that affect us on many different levels," says Newberg. "There is no one simple way of looking at these kinds of questions."
Science and the Afterlife
Across the country, at the University of Arizona, professor of Neurology and Psychiatry Gary Schwartz would probably say: "Amen" to that.
Perhaps the most controversial of the group of researchers dedicated to studying the "God spot" in the brain, Schwartz explores the question of whether consciousness survives death with the help of mediums (people who demonstrate unusual accuracy in describing intimate attributes of the dead to those who knew them well).
His experiments compare the brain waves and heart rates of both the medium and the person for whom he or she is trying to contact the dead.
"One of the fundamental questions is, 'How does a medium receive this kind of information?'" he explains. "To what extent are they using specific regions of the brain which are purportedly associated with other kinds of mystical or religious experiences?"
Schwartz says his research "is actually a window or a doorway, if you will, to a much larger spiritual reality which integrates ancient wisdom with contemporary science."
He concludes that the human brain is wired to receive signals from what he calls a "Grand Organizing Design," or G.O.D.
"Survival of conscience tells us that consciousness does not require a brain, that our memories, our intentions, our intelligence, our dreams? all of that can exist outside of the physical body," says Schwartz. "Now, by the way, that's the same idea that we have about God — that something that is "invisible," that is "bigger than all of us," which we cannot see, can have intellect, creativity, intention, memory and can influence the universe."
The Quest for Larger Things
Like the other researchers interviewed for Nightline, Schwartz suggests that his work has taken him on a personal spiritual journey, requiring him to ask himself hard questions about science, faith, and reason. And Schwartz says that rather than diminishing faith, inquiries like his should enlarge the world's understanding of it.
On that point, he and theologian John Haught agree.
"Faith is the sense of being grasped by this higher dimension, or more comprehensive, or deeper reality," says Haught. "If we could come up with clear proof or an absolutely mathematically lucid proof or verification of deity, then that would not be deity — it would be something smaller than us.…"
— Nightline producer Joe O'Connor contributed to this report.