example: a man is whacked in the head, and suddenly is blind. If you asked him to describe the scene, its pitch black. however, if you put him in front of a table and say pick up the knife, he'll reach in the right direction. heard about this at uni in my biology unit. apparently, your brain divides sight into two departments - conscious vision and reflexive vision. when the part of the brain controlling conscious is damaged, your reflexive vision (controlled by a different part of the brain) may still work. while the tv screen in your head is broken, your eyes are still functioning and apparently in studies people with blindsight demonstrated a high accuracy of locating or reacting to objects which utilise reflex vision. hopefully madanthony can support/correct/declare bullshit.
Very interesting Codan, do you have a source other than that you heard it at Uni? There was a tv-show recently that showed a blind man that claimed to 'see' objects by making clicking sounds (like a dolphin). I thought it was bullshit at the time, but maybe he found a way to utilize his subconscious vision.. I didn't see the show myself, so I don't know if he lost his vision due to brain-damage. I do know that he hadn't always been blind.
I know their hearing gets way more sensitive, but this was ridiculous. At least what they told me about it was.
Maybe he wasn't a human then. Maybe he was one of those bipedal dolphins from Sirius, or Nephilim. Please Register or Log in to view the hidden image!
Me either Please Register or Log in to view the hidden image! Anyway, I hope Codan has some sources as it's pretty interesting.
It is. I also heard blindness can cause "astral" vision, and naturally develop the inherent intuitivity to maximum. It seems pretty regular to be able sense objects though, it would explain the extreme offensiveness experienced whenever being hit by unidentifyed flying objects.
If it is the same show I've seen, it was a young boy from California who lost his eyes to cancer early on in life. I had my questions about this as well, but his accuracy [in places that he knew] was incredible! I was thouroughly amazed. I believe the title of the show was called 'The boy who sees sound.'
We'll never be as good as dolphins or bats, sure, but we can still learn to echo-locate. http://www.mindhacks.com/blog/2009/07/human_echolocation_a.html
For sources, there's heaps on google scholar (though most looked very specific and technical) and theres a wikipedia article. Unfortunately i was a tightass this semester and didn't buy the textbook, but at the bottom of the post is the uni info. nope, with blindsight your eyes are fine, and only a certain part of the brain is damaged. whilst you can't 'see', your eyes and the attached neurons are still transmitting information, which you can respond to by reflex. something i've noticed is i can tell how close i'm driving to another car/wall/safety rails etc. by hearing my bike exhaust (its loud) grow louder (i figured it was bouncing back at me). i grabbed this off the uni lecture's powerpoint presentation (luckily they're still up even though exams are over). The unit this is from is "biological psychology and perceptual processes".
I was talking to Enmos, asking long-windedly if the show was the same that I've seen, that wasn't a case of blindsight.
I don't know, Ttwh. I didn't see it myself, someone told me about it. But it quite possibly was the same show. Interesting article, but not quite comparable with what the dude could do in the TV-show.
I was just reading about blindsight in this BBC article. Blindsight: The Strangest Form of Consciousness It’s very interesting. BillyT has mentioned it before and C C brought it up in this topic. To do things without knowing is sort of creepy. It's something we all do, though.
No one has true "blind sight" without eyes; but other senses in the blind are more highly developed - they often have "facial vision" - an awareness that something is near their face. (Probably by the interruption of back ground heat radiation if near object is radiating different IR.) True blind sight is due to fact a small (in humans, but at least twice larger in Rhesus monkey) fraction of optical nerve signals, all of which go into the LGN, then this small fraction go to the "superior collegium" (If I recall correctly the name) instead of with the vast majority going to V1 from the LGN. With V1 destroyed you are blind - no conscious awareness of the visual world, but you can have "blind sight." In humans it is mainly demonstrated by how you shape your hand to grasp things - very differently if someone is handing you a book instead of a water glass. You will adjust your grasping hand correctly BEFORE any physical contact with the object being handed to you. Monkeys can do this and more. For example pick up a nut from the floor, without grouping around for it and of course, with their thumb set to squeeze the nut against a finger or two, PRIOR to contact with the nut.
