Sister Constance Fitzgerald of the Carmelite Monastery in Towson can't describe Unio Mystica, the direct and immediate experience of God that Christian mystics seek through contemplative prayer. All she can say is that it's a gift from God -- achieved through a lifetime of fidelity.
But is it also a gift of human brain biology? Mario Beauregard, a University of Montreal neuroscientist, wants to find out exactly what's going on during this most intimate of religious experiences.
To do this, he'll use functional magnetic resonance imaging, positron emission tomography and multichannel electroencephalograms. He hopes to peek inside the minds of nuns as they try to achieve their union with God. "With this knowledge, I think it could be possible to assist people to have some kind of spiritual experience," he says.
Beauregard is one of a growing number of scientists using the latest technology to study the physiological basis of religious and spiritual experience. In addition to nuns and monks, researchers are studying epileptics -- who often report visions during seizures -- as well as normal people who don't have intense religious experiences.
Their new field, known as neurotheology, is raising questions about the nature of God and the human soul in an unprecedented -- and controversial -- effort to bridge the gap between science and religion.
"The brain is built in such a way that allows us as human beings to have these religious experiences extremely easily," says radiologist Andrew Newberg, co-author of Why God Won't GoAway: Brain Science and the Biology of Belief.
But scientific critics say these researchers aren't really studying spirituality at all. They're just cataloging an intense emotional experience like any other -- such as the birth of a child. For their part, some theologians wonder why science is trying to enhance spiritual life at all -- since religion has known how to do it for ages.
"All they have found is that these are genuine emotional experiences, which I don't think anyone ever questioned," said Dr. Mortimer Ostow, a retired professor of pastoral psychiatry at the Jewish Theological Seminary in New York.
Regardless of its origins, Newberg says, the human brain is physiologically equipped to experience the transcendent -- a condition that has advanced mankind's belief in the notion of a greater power. It's a conclusion he and his mentor, Eugene d'Aquili, reached after studying Buddhist monks and Franciscan nuns at the University of Pennsylvania in the late 1990s.
Measuring blood flow in the brain as their subjects reached the height of meditation or prayer, they noticed decreased activity in the parietal lobe, the part of the brain responsible for orienting oneself in space and time. As time and space slip away, Newberg says, "you lose your sense of self."
"You have a notion of a great interconnectedness of things," Newberg said. "It could be a sense where the self dissolves into nothingness, or dissolves into God or the universe."
If the brain is somehow responsible for these spiritual experiences, it might explain the worldwide commonality of religious belief in general -- whatever form it takes, Newberg said.
But Ostrow believes that's a stretch. "What they are saying essentially is that when people have spiritual experiences -- and they don't always define that clearly -- that characteristic things happen in the brain," Ostow said.
Far more controversial is the research of Michael Persinger, who has spent a decade simulating what he calls "a God experience," even among nonreligious subjects, in his lab at Laurentian University in Sudbury, Ontario.
Wearing a helmet that directs a complex magnetic field to the brain, subjects describe a "sensed presence" as they sit alone and blindfolded in a silent chamber, Persinger says.
The experience is deeply emotional, and subjects lose their sense of time while it occurs, Persinger says. It slowly fades when Persinger "turns them off," leaving subjects with a sense of loss. Afterwards, many subjects describe the experience as a visit from God.
"The [God] experience comes from the brain, there is no doubt about it," he said. "All experience is produced in the brain -- that is the bottom line."
Critics say Persinger is too simplistic. Sister Ilia Delio, a neuropharmacologist and professor of ecclesiastical history at Washington Theological Seminary, argues that there's a difference between God and a "God experience."
"Our experience of God is going to have a biological basis, but that experience cannot be equated with God," she said.
Even if they're willing to accept a physiological basis for spirituality, critics aren't necessarily impressed by the research. "I guess the most prosaic question is, 'So what?'" said Neil Gillman, professor of Jewish philosophy at the Jewish Theological Seminary. "Have we understood the religious life?"
He and other theologians point out that prayer and meditation are only part of the religious experience, which includes ritual, charity, study and good works.
But Newberg, Beauregard and other neuroscientists hope their efforts can make spiritual experiences more accessible.
Beauregard said his research with Unio Mystica may lead to an electrical or pharmacological stimulant that could enhance spiritual experience. Newberg noted that some cultures have historically used mind-altering substances such as peyote to this effect.
At the Carmelite monastery in Towson, Fitzgerald said she is wary of science diminishing traditional religious practice.
"I think we have not begun to tap the possibilities inherent in contemplative prayer for the transformation of people," Fitzgerald said. "We don't have faith that a life of profound prayer really could affect the human race."
Beauregard, meanwhile, is seeking Carmelite nuns in Canada who are willing to participate in his study. Some are interested, he said, but others worry that he is trying to prove Unio Mystica is merely an illusion of the brain.
He and other spiritual researchers deny that motive. "The last thing I would want to do is have our scientists going around in their research with respect to their subjects and somehow remove their sense of spirituality," said Solomon Katz, head investigator at the Metanexus Institute in Philadelphia.
The institute, backed by retired Wall Street mutual fund guru John Templeton, funds Beauregard's investigation and others like it.
For some clergy, such as the Rev. Jerry Larsen, a United Methodist pastor in Long Beach, Calif., the new science has a positive effect on their faith. "If something happens physically when we are doing something spiritual, then the two are very closely connected and one can help us understand the other," said Larsen, author of Religious Education and the Brain.
"Our spiritual lives are held in the synapses in the cortex. ... Maybe even spirit is born within the brain rather than being given to us from a supernatural power."