Dion McGregor (1922-1994) was a songwriter who penned a hit for Barbra Streisand but he has cult (and now scientific) fame as a prolific sleep-talker, or rather sleep-storyteller. While asleep, McGregor would narrate his strange, creepy, and sometimes risque dreams in great detail. Have a listen below! In 1964, Decca Records released an album of recordings of McGregor's sleep-talking, The Dream World of Dion Mcgregor – He Talks in His Sleep, with cover art by Edward Gorey. A book of transcripts, also illustrated by Gorey, was also published that year with the same title, The Dream World of Dion McGregor. Numerous CDs have followed and the entire body of work has become a great source of data for sleep researchers at Harvard Medical School. They're published a new paper about McGregor in the journal Imagination Cognition and Personality. From the British Psychological Society:
The researchers think there are two explanations for the differences between McGregor's somniloquies and typical dream content. One is that much sleep talking does not occur during dreams, and in fact people's brain waves during sleep talking are distinct from those usually seen during dreaming, featuring fewer waves in the alpha frequency range, which they explained could be a sign of more frontal brain activity. The researchers further describe this as "an unusual state midway between waking and sleeping" (backing this up, there is a McGregor interview in which he says a sleep researcher recorded his brain activity during sleep talking and found a mix of sleep and waking brain wave patterns).
More at the BBC: "The dark tales of the world's most epic sleep-talker"