Thursday, June 3, 2010

Do you want to hallucinate? Watch this image. #medtweeps #psychiatry

"A hallucination is a percept experienced in the absence of an external stimulus to the corresponding sense organ" - Oxford textbook of psychiatry

Jaspers suggested the following defnition 'a false perception which is not a sensory
distortion or a misinterpretation, but which occurs at the same time as real

You are having a visual hallucination when there is no external object, but you are still percieving that there is an object. Visual hallucinations are seen in some psychiatric illness.Recently i came across this interesting image in Scientific American. Its called the Yorick's Skull. This was the image.

doodle.png  on Aviarydoodle.png on Aviary.


The site says, 'To experience a vintage afterimage illusion, stare at the X in Yorick’s left eye socket for about 30 seconds. Then look away at a wall or piece of paper, and you will see a ghostly apparition.'


When we stare at a wall after seeing the image, there is no external object. But we are still able to percieve the image of the ghost. So is this an illusion?? or is it that we are hallucinating??

Posted via web from Inquisitives' posterous