More recently, Orrin Devinsky and his colleagues have been able to make video EEG recordings in patients who are having such seizures, and have observed an exact synchronization of the epiphany with a spike in epileptic activity in the temporal lobes (more commonly the right temporal lobe).

"I was flying forwards, bewildered. I looked around. I saw my own body on the ground. I said to myself, 'Oh shit, I'm dead.'"

Ecstatic seizures are rare -- they only occur in something like 1 or 2 percent of patients with temporal lobe epilepsy. But the last half century has seen an enormous increase in the prevalence of other states sometimes permeated by religious joy and awe, "heavenly" visions and voices, and, not infrequently, religious conversion or metanoia. Among these are out-of-body experiences (OBEs), which are more common now that more patients can be brought back to life from serious cardiac arrests and the like -- and much more elaborate and numinous experiences called near-death experiences (NDEs).

Both OBEs and NDEs, which occur in waking but often profoundly altered states of consciousness, cause hallucinations so vivid and compelling that those who experience them may deny the term hallucination, and insist on their reality. And the fact that there are marked similarities in individual descriptions is taken by some to indicate their objective "reality."

I've come to appreciate how much of what we accept as reality is what our brain is presenting us.