Spiritual experiences would be expected to have some physical effects

He replied that as a medical man he was at a loss to explain these events, and he had to think of them in "spiritual" terms now. I countered that, with no disrespect to the spiritual, I felt that even the most exalted states of mind, the most astounding transformations, must have some physical basis, or at least some physiological correlate in neural activity. Oliver Sacks, Musicophilia: Tales of Music and the Brain. New York: Knopf, 2007, p. 12. "He" is a doctor who was struck by lightning. As a result, he developed a love, even a craving, for classical piano music, and started to become a piano performer. He also had ". . . both a near-death experience and an out-of-body experience . . ." (pp. 12-13) caused by the lightning strike.

Sacks has some knowledge of research into near-death and out-of-body experiences. He does not reject their existence out of hand. And, most likely, he is right. When Jesus turned water into wine, the wedding guests drunk it. When Moses raised his rod over the Red Sea, the sea parted. These were two physical manifestations of miracles. Many others could be listed. So why not expect that, say, a revelation from God, as many of the prophets had, or a vision, or dream, or some sort of ecstatic experience, would also have physical effects, at least temporary ones, on the brains of the people that are experiencing them, just as we may be able to measure brain cell activity when other events are taking place? Surely, when we have any sort of experience, something (probably temporary, perhaps not) must be happening to at least a few of our brain cells?

Here's a recent report of some interesting research involving measurement of brain activity in response to beautiful images (No images of humans were included.)

This relates to what has been called the mind-body problem.