PHILADELPHIA — Religion and science can combine to create some thorny questions: Does God exist outside the human mind, or is God a creation of our brains? Why do we have faith in things that we cannot prove, whether it's the afterlife or UFOs?

The new Center for Spirituality and the Mind at the University of Pennsylvania is using brain-imaging technology to examine such questions and to investigate how spiritual and secular beliefs affect our health and behavior.

"Very few are looking at spirituality from a neurological side, from the brain-mind side," said Dr. Andrew Newberg, director of the center.

A doctor of nuclear medicine and an assistant professor at Penn, Newberg also has co-authored three books on the science-spirituality relationship.

The center is not a bricks-and-mortar structure but a multidisciplinary team of Penn researchers exploring the relationship between the brain and spirituality from biological, psychological, social and ideological viewpoints. Founded last April, it is bringing together some 20 experts from fields including medicine, pastoral care, religious studies, social work and bioethics.

"The brain is a believing machine because it has to be," Newberg said. "Beliefs affect every part of our lives. They make us who we are. They are the essence of our being."

Spirituality and belief don't have to equate to religious faith, Newberg said. The feelings of enlightenment and well-being some derive from religion can come to others through artistic expression, nonreligious meditation, watching a beautiful sunset or listening to stirring music.

"Atheists have belief systems, too," Newberg said.

How does the center test the relationship between the mind and spirituality?

In one study, Newberg and colleagues used imaging technology to look at the brains of Pentecostal Christians speaking in tongues — known scientifically as glossolalia — then looked at their brains when they were singing gospel music. They found that those practicing glossolalia showed decreased activity in the brain's language center, compared with the singing group.

The imaging results are suggestive of people's description that they do not have control of their own speech when speaking in tongues. Newberg said scientists believe that speech is taken over by another part of the brain during glossolalia, but did not find it during the study.

Other recent studies looked at the brains of Tibetan Buddhists in meditation and Franciscan nuns in prayer, then compared the results to their baseline brain-activity levels. Among other changes, both groups showed decreased activity in the parts of the brain that have to do with sense of self and spatial orientation — which suggests the description of oneness with God, of transcendence sometimes experienced in meditation or prayer.

Prayer and meditation also increase levels of dopamine, often referred to as the brain's pleasure hormone.

"The mind and the body are the flip side of the same coin," said Dr. Daniel Monti, head of Thomas Jefferson University Hospital's integrated medicine center. "Now we know some of the mechanisms by which that occurs, and it's becoming better and better understood."

The integrated medicine center teaches patients with cancer, chronic pain and other ailments to work things like meditation and proper diet into their conventional therapy, Monti said. Such thinking seemed "fringy" to many people a decade ago, but it is becoming widely accepted by the medical community and patients, he said.