On Saturday, the subject of Radio National's All In The Mind show was "delusions." You can listen to the show as Real Audio, MP3, and also subscribe to the Podcast. From the program description:
Cotard’s syndrome is the belief that you have died, and for sufferers it is a terrifying state. Delusions can take many forms, from widespread paranoia to a specific and singular delusion – you might think an impostor has replaced your spouse. These misbeliefs are commonly associated with schizophrenia, but they can also occur in people with brain injuries, Huntington’s and Parkinson’s disease and dementia. The Macquarie Centre for Cognitive Science is seeking to explain delusions by developing a model of how we all come to accept or reject beliefs.
Link (via Mind Hacks)