January 18th, 2008

Dreams and Waking Hallucinations


Here’s a damn interesting article from Damn Interesting, about Bonnet visions – hallucinations, named after a man called Charles Bonnet, and had by otherwise-sane, conscious people who are often in the unfortunate situation of slowly going blind. People with these symptoms are known as having Charles Bonnet Syndrome and this article also explores connections between such hallucinations and dreams. Are they result of the same workings of the brain?

Some have suggested that Bonnet visions are the product of the same mechanisms that generate dreams. Clearly the mind is starved of visual input during sleeping periods, so it stands to reason that both dreams and CBS hallucinations may be the result of the same thing: the visual cortex becomes bored due to lack of stimulation, and gratifies itself using stored imagery. This notion is further supported by sensory deprivation experiments, where subjects experience hallucinations when placed in complete darkness for long periods of time. But the explanation fits the problem imperfectly, because dreams include sound and sensations, whereas Bonnet-visions are confined to sight.

Update 9/11/2010: Neurologist Oliver Sacks gives a more informed summary of Charles Bonnet syndrome and its mechanisms in this TED talk.


No comments yet.

RSS feed for comments on this post. TrackBack URI

Sorry, the comment form is closed at this time.

Powered by Wordpress. Theme info.
Original content © MMIX Jonathan Beaton, all rights reserved.