In his latest book Hallucinations, neurologist Oliver Sacks collects stories of individuals who can see, hear, and smell things that aren’t really there—such as strange voices, or collages of unrecognizable faces—and explores the disorders and drugs that can produce such illusions.

In the SciFri Snack: Neurologist Oliver Sacks, author of Hallucinations, shares a memory from his days experimenting with psychedelic drugs. In this 60 second clip, hear him describe an almost religious experience in his own words. Hear more and join the conversation on SoundCloud.