I have long been fascinated by sight. From the simple detection of light in a neurologically meaningful but simple way, to the complex perception of objects and space including objects and shapes never before experienced, to the fascinating and fun tricks of vision.

 

I recently heard of a fascinating syndrome, common among the visually impared and blind, called Charles Bonnett syndrome. People experiencing Charles Bonnett syndrome hallucinate. It's not the psychotic dysphoric hallucinations that most people think of when they hear the word "hallucination", rather what they experience is a sort of "movie in the mind" where images of things, people, faces, etc. engage in mundane or repetitive activities. The person experiencing the hallucination will almost never recognize the people or places and things in the hallucination.

 

What makes this most interesting is that there has been opportunity to have people experiencing Charles Bonnett syndrome hallucinations while in an FMRI. This has revealed some interesting aspects of how the brain perceives visual information.

 

In looking around for more information, I fond this TED talk by Oliver Sacks, a man who deals with Charles Bonnett syndrome in his patients quite often. He explains this phenomenon and what it has taught us far better than I could:

http://blog.ted.com/2009/09/what_hallucinat.php

Haha... I just watched that video this weekend. It's wild that you'd create a thread about it today.

 

 

The human mind is an amazing and curious part of nature.

If memory serves, you'll also find a good discussion of it in his latest book, "Musicophilia".