Wednesday, January 14, 2009

Blindsight

Recent experiments by Beatrice de Gelder of Tilburg University in the Netherlands showed that a blind man in Switzerland could respond to the visual world without his conscious awareness.

“TN,” as he is known, has a unique condition. His occipital lobe, the part of the brain responsible for seeing, was damaged by two strokes, but his eyes still function normally.



When he was asked to navigate past a series of obstacles, he responded successfully. The researchers ruled out auditory or other non-visual perception. Apparently, TN was using a subconcious type of vision. He could not form an image in the conventional sense.

“Blindsight” is the ability to see at the subcortical level, where images are processed by the amygdala and other primitive parts of the brain. As the New York Times put it: “The brain has a primitive, subconscious visual system working in tandem with our conscious visual sense.”

Other experiments have shown that blind-seeing patients also respond emotionally to social signals like angry faces, even though they’re not aware of seeing them at all.

What are the implications of these revelations for us as artists? Even though our visual systems are intact, there is a deep part of us that responds to basic images—things like barriers that we might bump into, sources of illumination, or faces that might threaten us.

We’ve all experienced related phenomena. It happens when we react viscerally to something that looks like a snake or an insect, making us recoil a split second before we consciously register the object. It happens when we look at an optical illusion that persists in “fooling” our rational mind. It happens when a painting or a book cover “speaks” to us from across the room before we’re even aware of it.

Vision is more than just a function of rational awareness. It is also a profound ocean of experience, with strange stirrings that move us deep below the surface.
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Article in the Guardian, link.

8 comments:

Michael Warth said...

Interesting James...good post. My wife recently suffered a stroke in Feb. 2008 (she is 36) and it really came a s a surprise. She is getting much better now but I noticed she still has trouble with the "ooh" sound in words like noodle, blue, boo, etc. I understand a stroke can damage as much as the volume of two ping pong ball sized areas of the brain. It is amazing to me how the brain works. I was not aware of "blindsight" - another point to consider as artists...how much of what we paint is from observation versus memory? I have been working on a still life study and noticed that I do much better if I look and study more than just "blindly" paint what I think I see. I know...that is what we should do but really? Do our paintings suffer because our ability to memorize what we see? Are we special in the sense we memorize visuals better than non artists. PLEASE do more posts like this...I would love to read you take on how the brain works in relation to artist's brains.

Erik Bongers said...

Ever been reading your cell phone while walking an obstacle path or a crowded main street (that's moving obstacles)?

Ever looked at your drawing/painting having this funny feeling that there's something wrong with it?
Grabbed a mirror to check if you can spot the error in the flipped image?

Ever made a portrait in a very precise step-by-step approach, and it turns out rubbish...and then you do a quick to-hell-with-it sketch and it turns out so much better?

Why bother conciously creating our art, if our subconciousness seems to be better at it (at times) and worse, when our subconsiousness seems to be sadistically telling us that it 'knows' something we would like to know...but it's not telling us...hehehe!

Joan M. Mas said...

The world of perception and illusions is always amazing. Just yesterday I found a very interesting article with some perception alterations you can experiment at home (here, with names such as The Ganzfeld procedure, the incredible shrinking pain, the rubber hand illusion and the Pinnochio illusion.).

Chris Jouan Illustration said...

Robert Burton's book On Being Certain covers the primitive parts of the brain and the phenomenon you describe in detail. It was an impressive read and describes how our subconscious is in charge of doing everything and our conscious is in charge of making up good reasons for those actions.

Mr. Kinder said...

Sharon Begley wrote a book titled Train you Mind, Change Your Brain in which she discusses neuroplasticity, the brain's ability to adapt and change.

In it she discusses how the brain can learn to process sensory information in new ways if its usual processing centers are unavailable. She discusses evidence that suggests that how you use your mind actually changes the way your brain organizes itself. (We tend to think that only the opposite relationship exists.) TN's ability to see while blind fits into this new theory of neuroplasticity quite neatly.

front said...

Hi James,

I'm curious... how do you choose your travel destinations... one day you are in Moroco, next day in Ireland. What makes you to jump like that?

James Gurney said...

Thanks to all of you for these helpful comments.

Chris, I certainly look forward to reading "On Being Certain." It's on order from my library.

Dan, thanks for mentioning neuroplasticity which is an amazing phenomenon. I'm not sure how much of a role that may have played in this case. My take on the study was that the subconscious visual processing is going on with both impaired and unimpaired people, but that the lack of conscious sight made the deep brain skills more obvious.

Erik--you gave a lot of great examples, and I think scientists in this field should talk to artists, because we're thinking about this sort of thing all the time.

Michael, you raise some central ideas about "seeing" blindly as an artist, or you might say, copying without understanding versus using memory. That's a big topic that I'll try to tackle in various ways in future posts.

Front: Sorry if I've been inadvertently misleading. The trip to Morocco was November 2008; the trip to Ireland was about ten years ago.

Alandiras said...

Amazing article!