Hallucination: Through the Doors of Perception -
Geoff Watts explores the science of hallucination. The phenomenon is probably as old as the human brain, and examples exist throughout history and across cultures.
Hallucinations aren't what they used to be. Time was when reporting a divine vision would bring fame or fortune, and have a queue of people wanting to touch your robe, receive a blessing, or recommend you for sainthood. The Enlightenment changed our view of hallucination and nowadays you'd be more at risk of being handed a prescription for a major tranquilliser or even sectioned under the Mental Health Act for reporting what you saw or heard. Hallucinating, in essence, the experience of seeing or hearing (and sometimes smelling or touching) something that by any objective measure, isn't there, has been linked to a wide variety of causes. From the use of mind-altering substances such as LSD, to the complex collection of often distressing symptoms labelled schizophrenia. Neurological damage, dementia, post-traumatic stress disorder, depression, stress, narcolepsy - all these and more have been linked to hallucination. But there are also examples of otherwise 'healthy' individuals who have experienced vivid and sometimes distressing hallucinations which for most of the last century, science has largely overlooked. But with the advent of fMRI scanning, where researchers can observe the hallucinating brain in action, it is these "healthy" individuals who are beginning to open the doors of perception and which may provide new insights and treatments for psychosis and schizophrenia.
In this programme, Geoff Watts meets researchers attempting to unlock the mysteries of hallucination as well as some of those who experience the phenomenon. Geoff visits Dr Dominic Ffytche of the Institute of Psychiatry in London, and undergoes a stroboscopic experiment designed to induce hallucinations in subjects whilst their brains are being scanned. We hear some of the vivid accounts from hallucinators, including Doris, who has macular degeneration. Over the last year, her failing eyesight has resulted in an array of objects and images appearing before her with startling clarity, from relatively benign baskets of flowers to the rather more distressing sight of dark, haunting figures sitting by her bed. Her condition is known as Charles Bonnet Syndrome and Dr Ffytche estimates that over 2 million people suffer from this in the UK alone, mostly in silence, due to the fear of being labelled as 'mad'. Geoff also visits Kelly Diederen's lab at Cambridge University, which is investigating the origin of auditory hallucinations - hearing voices. Common in people with schizophrenia, Dr Diederen is instead, scanning the brains of so-called "healthy hallucinators", individuals who otherwise lead perfectly functional lives save for the fact that they hear voices on a daily basis. Could they hold the key to understanding and treating a key symptom of psychosis? And Geoff talks to internationally renowned neurologist and author, Dr Oliver Sacks, about his own experience of hallucination as well as his new book on the subject.
- Broadcast on BBC Radio 4, 9:00PM Thu, 9 May 2013
- Available until 12:00AM Thu, 1 Jan 2099
- First broadcast BBC Radio 4, 9:00PM Wed, 17 Oct 2012
- Duration 28 minutes