It is here that they have agreed to try to relive unio mystica, a religious experience so intense that Christians profess to sense their Lord as a physical presence. The nuns hope to help Montreal neuroscientist Mario Beauregard uncover just what happens in their brains when they feel the hand of God.

Their openness to scientific examination is a sign of a relatively recent rapprochement between science and religion, especially in the new field of neurotheology, which uses the tools of psychology and neuroscience to probe the neural underpinnings of religious experience

What all the new research shares is a passion for uncovering the neurological underpinnings of spiritual and mystical experiences—for discovering, in short, what happens in our brains when we sense that we "have encountered a reality different from—and, in some crucial sense, higher than—the reality of every- day experience," as psychologist David Wulff of Wheaton College in Massachusetts puts it. In neurotheology, psychologists and neurologists try to pinpoint which regions turn on, and which turn off, during experiences that seem to ex- ist outside time and space.