Sue Lawley's castaway this week says changing her mind was one of the most difficult things she's ever had to do. After an out-of-body experience, psychologist Susan Blackmore set out to study and prove the existence of the paranormal. Twenty years on, she's a convinced sceptic.

She continues, however, to be fascinated by the question of consciousness. In particular, the new theory of memes which examines how habits and beliefs are passed on from one person to another. At their worst, she says, they're evident in fascism or religious fundamentalism. At their best, they're responsible for our co-operation and kindness.

[Taken from the original programme material for this archive edition of Desert Island Discs]

Favourite track: Not Fade Away by Grateful Dead