Blind, Yet Seeing

December 26, 2008 9:33 AM

Blind, Yet Seeing : New research into blindsight from Harvard University and M.I.T. showing that people who have been blinded by brain injury have resources beyond sight to do such tasks as navigate an obstacle course (movie).
posted by grapefruitmoon (21 comments total)

In the 1970s Nicholas Humphrey found that a rhesus monkey with its visual cortex removed could still see.
posted by parudox at 10:35 AM on December 26, 2008

There is so much crap happening inside my head that I have no idea about! It's kind of cool and kind of terrifying.
posted by aubilenon at 11:29 AM on December 26, 2008

Of course. You're not actively seeing 90% of what you think you're seeing anyway, it's mostly a 3d model constructed from memory.
posted by empath at 11:36 AM on December 26, 2008 [2 favorites]

Ben Underwood taught himself to use echo location to navigate. (5 part doc)
posted by carsonb at 11:38 AM on December 26, 2008

wow grapefruitmoon, this is astonishing! The brain and mind are so awesome. Just endless wows.
posted by nickyskye at 11:47 AM on December 26, 2008

I already knew this from reading Daredevil comic books (... which also taught me that large men in white suits are preternaturally light on their feet and tend to run global criminal organizations).
posted by BitterOldPunk at 11:53 AM on December 26, 2008

Of course. You're not actively seeing 90% of what you think you're seeing anyway, it's mostly a 3d model constructed from memory.

I'll add my erudite thoughts: SOOOOO COOOOOOOOL
posted by Popular Ethics at 12:02 PM on December 26, 2008 [2 favorites]

I have a close friend who's blind, and the single most gifted and brilliant musician I've ever known in a life in music. I played in his band for a few years, and it was an education in seeing with your ears to be around him. He runs a huge digital recording studio -- and one of the most sought after producers in his niche of music -- without seeing a single light or meter or knob, all by feel and ear, and he never makes a mistake, and runs circles around seeing people who know their shit in the studio, like me. I remember that he could tell how full the dance floor was, and adjust his sets accordingly, by the resonance of the room while we were playing. And on long drives back from gigs he would take apart the night's performance note by note, remembering every single mistake his sidemen made (he was nice about it, but a perfectionist). ["You remember that flat seven chord in 'Undo the Right,' well you missed it in the first chorus . . . that kind of thing."] I was sometimes his "eyes" for him on the road, which was an incredible experience.

My favorite story -- and it still gives me chills -- is from when he came to NYC for a visit a few years ago. He had never been here before, so I asked him what he wanted to do (after visiting every music store in town and flat out scaring NYC pickers with his chops).

He asked to go to the top of the Empire State Building. I wondered what it could offer, but took him up (my own first time there too, despite having grown up nearby).

So we get up there and he has me take him to each corner of the observation deck. He stands there listening for a while and then asks me "how far away is that siren, that helicopter, that traffic noise, that boat horn . ." We repeat in each corner.

As we start down he says, with satisfaction, "now I finally understand how big New York really is."

He was listening for the size of the city.
posted by fourcheesemac at 12:10 PM on December 26, 2008 [126 favorites]

(Awesome FPP, by the way)
posted by fourcheesemac at 12:11 PM on December 26, 2008

Great post. Blindsight is a fascinating phenomenon.

More at Not Exactly Rocket Science.
posted by homunculus at 1:02 PM on December 26, 2008

a rhesus monkey with its visual cortex

Poor monkey.
posted by dunkadunc at 1:18 PM on December 26, 2008 [1 favorite]

Removed, I meant.
posted by dunkadunc at 1:20 PM on December 26, 2008

Further evidence
posted by fuq at 1:30 PM on December 26, 2008

NPR covered this story a few days ago on Morning Edition. This page has the story, including a link to the audio. It's nice to hear the story direct from the scientist's POV.
posted by Ike_Arumba at 2:07 PM on December 26, 2008

Been fascinated with the concept of blindsite for a long time, so thanks for this.
posted by fearfulsymmetry at 3:59 PM on December 26, 2008

If I had a visual of cortex *cough* I think I'd want part of my brain removed, too.

(sorry, man, too easy a joke!)
posted by notsnot at 6:06 PM on December 26, 2008

What was?
posted by George_Spiggott at 7:22 PM on December 26, 2008

Hey, my story was sidebarred. Thank you to those who recommended it . . . .
posted by fourcheesemac at 11:51 AM on December 27, 2008

I experienced something like blindsight in a dream once. In this dream, one of my friends had learned, through some network of esoteric knowledge, about how to modify some CD or DVD to create something reminiscent of Snow Crash. When played in the DVD player, the television set displayed snow. I sat in front of the TV and stared at it, and after a few seconds I could momentarily see some random symmetrical shape in it, and my entire field of vision suddenly became snow. I proceeded to blindly walk around the house, but I was still aware of what was in front of me. I had a spatial sense of the flight of stairs in front of me, even though I couldn't see them.
Of course, I have no way of knowing if this was an accurate experience of blindsight, since I've never actually experienced it.
posted by Stove at 8:03 PM on December 27, 2008 [1 favorite]

Blindsight is also the title of an excellent hard-SF, which touches on the subject, along with other weird stuff in neurology and the philosophy of mind.

I do think it's not quite right to say that blindsight is about resources "beyond sight" (like the Daredevil's sense of sound) -- it is rather about unconscious sight. (That's why it happens to people with brain injuries, not people with missing eyes.)
posted by grobstein at 9:47 PM on December 27, 2008 [2 favorites]

I do think it's not quite right to say that blindsight is about resources "beyond sight" (like the Daredevil's sense of sound) -- it is rather about unconscious sight.

Yep, what grobstein said. I first learned about and became fascinated by this phenomenon in a Philosophy of Mind course during my undergraduate studies.

In cases of sighted blindness, the eye still functions on a mechanical level, the sensory information it takes in still makes it to the brain as usual, and the brain still processes and interprets that raw information as usual--it just doesn't construct a visual representation of the information that gets passed on to the perceiving subject in the form of a conscious experience.

This perplexing outcome is possible because the parts of the brain that process raw visual information and the parts that generate a conscious visual experience are functionally autonomous. When the parts responsible for creating the conscious experience of what we see are damaged or destroyed while the other parts remain intact, you get sighted blindness. You're not consciously aware of what you're seeing, but you still see it. (I believe past studies have confirmed even color recognition and identification in subjects with this condition.)

This phenomenon often comes up in PoM discussions, as an argument in favor of the epiphenomenalist view of consciousness, which maintains that conscious experience is essentially an evolutionary accident with no real bearing on human behavior. For obvious reasons, the epiphenomenalist position usually also leads to a rejection of free-will and intentional agency. It might be possible to settle the question of whether or not consciousness is merely epiphenomenal, however, if a test could be devised to demonstrate that blind-sighted individuals consistently demonstrate certain behavioral limitations or differences as a result of their condition, as compared to conventionally sighted individuals. A well-constructed test of some sort might put at least some of the most basic, frequently posed questions surrounding consciousness' evolutionary value to rest.

Thanks for this FPP! Good stuff...
posted by saulgoodman at 8:04 AM on December 29, 2008 [1 favorite]