Blindsight - Blind man can see and avoid obstacles

original source: http://www.nytimes.com/2008/12/23/health/23blin.html

Blind, Yet Seeing: The Brains Subconscious Visual Sense

William Duke
BLINDSIGHT A patient whose visual lobes in the brain were destroyed was able to navigate an obstacle course and recognize fearful faces subconsciously.


By BENEDICT CAREY
Published: December 22, 2008
The man, a doctor left blind by two successive strokes, refused to take part in the experiment. He could not see anything, he said, and had no interest in navigating an obstacle course — a cluttered hallway — for the benefit of science. Why bother?

You just had to see it to believe it, said Beatrice de Gelder, a neuroscientist at Harvard and Tilburg University in the Netherlands, who with an international team of brain researchers reported on the patient on Monday in the journal Current Biology. A video is online at www.beatricedegelder.com/books.html

Category:

Science & Technology

Tags:

• blindsight
• blind
• man
• see
• avoid
• obstacles
• zig
• zag
• without
• help

[chewbster]

I doubt most people read comments, they usually just post - the man's eyes are in normal condition - it's their communication with the brain that isn't proper

[MattWDavies]

Vsauce

[4tasteh]

No, it's because the optic nerve is still attached and there is still some input to the Superior Colliculus.

[KokendeBloem]

Lees het boek: "De Vrije Wil Bestaat Niet" van Victor Lamme en je begrijpt hoe eea werkt!

[SanderSpook]

I doubt this movie shows the truth: Blindsight is a phenomenon in which people who are perceptually blind in a certain area of their visual field demonstrate some response to visual stimuli.

As he is not completely blind, he still can see a large area by using regular eye movements like you and I. Therefore I am not sure if this is that special. Especially because his eyes are blurred. An eye-movement tracker should have been used to rule this out. 

[SamuelHorler]

Just read about this in my cognitive psychology book. My mind is blown.

[amir2e]

He's lucky he has that and isn't like most blind people.

[domingvs]

Amazing! He is not aware of the objects, still he can avoid them. It is almost unbelievable.

[sakadafreak]

Vsause

[charbby]

Vsauce

[escasheep97]

He can see the items but he wouldn't be able to tell you what they are. Is that correct? Like if you were to have him show you what obstacles were in his way he would still be able to show you, right?

[jcruzuk100]

That patient may have damage his ventral stream (blindsight) which connect the primary visual cortex with the inferotemporal cortex, in other words is only guided by his dorsal stream which control unconscious processes such as visual guided movements. very interesting.