[...] In the experiments, Newberg and D'Aquili used a technology called SPECT scanning to map the brains of several Tibetan Buddhists as they immersed themselves in meditative states. Later they did the same with Franciscan nuns who were engaged in deep, contemplative prayer. The scans photographed levels of neural activity in each subject's brain at the moment that person had reached an intense spiritual peak. The Buddhists typically described this moment as a blending into a larger oneness, and a sense of losing the self. The Franciscans described it as a sensation of a deeper, truer self being drawn into unity with God.
When they studied the scans, Newberg and D'Aquili's attention was drawn to a chunk of the brain's parietal lobe they called the orientation association area. The area is responsible for defining the limits of the physical self, and for generating the perceptions of space in which that self can be oriented. In simpler terms, it draws the line between the self and the rest of existence. This is a task of staggering complexity, which requires a constant stream of neural information flowing in from the senses. What the scans revealed, however, was that at peak moments of prayer and meditation, the flow of neural impulses to the parietal lobe was dramatically reduced.
This was exactly the result the two men expected, and based on their knowledge of brain function, they knew what its effects would be: the orientation area, deprived of the information it needed to draw the line between the self and the world, would generate a sense of a limitless awareness melting into infinite space. [...]