Tuesday, March 16, 2010

Sensory Deprivation, Revisited

I came across an interesting article at Wired Science this weekend. The title, "Out of LSD? Just 15 Minutes of Sensory Deprivation Triggers Hallucinations," hooks you in. The Hadley Leggett piece is essentially a review of new experiments in sensory deprivation.

I remember back in the seventies reading about research that some school was doing on sensory deprivation and its effects. (Sam Keen in Psychology Today?) What I recall is some kind of flotation chamber and the person would be put into it so they would float, and the other senses somehow stifled. Being eager to try new experiences I half wondered how to be part of those experiments.

The current version has persons sitting in the dark, in a soundless room on a comfortable chair. I half wonder if someone almost drowned in one of those chambers.

Here's the beginning of the story.

You don’t need psychedelic drugs to start seeing colors and objects that aren’t really there. Just 15 minutes of near-total sensory deprivation can bring on hallucinations in many otherwise sane individuals.

Psychologists stuck 19 healthy volunteers into a sensory-deprivation room, completely devoid of light and sound, for 15 minutes. Without the normal barrage of sensory information flooding their brains, many people reported experiencing visual hallucinations, paranoia and a depressed mood.

“This is a pretty robust finding,” wrote psychiatrist Paul Fletcher of the University of Cambridge, who studies psychosis but was not involved in the study. “It appears that, when confronted by lack of sensory patterns in our environment, we have a natural tendency to superimpose our own patterns.”

The findings support the hypothesis that hallucinations happen when the brain misidentifies the source of what it is experiencing, a concept the researchers call “faulty source monitoring.”

“This is the idea that hallucinations come about because we misidentify the source of our own thoughts,” psychologist Oliver Mason of the University College London wrote in an e-mail to Wired.com. “So basically something that actually is initiated within us gets misidentified as from the outside.” Mason and colleagues published their study in October in the Journal of Nervous and Mental Disease.

What's astonishing to me is how dramatic the effects were after only 15 minutes of sense deprivation. If I've peaked your interest in this topic, you might enjoy the rest of the article. We'll keep the lights on for you.

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