Vision is a 'Reflex'

kernkopje writes "A recently publicized book by two neurobiologists at Duke University introduces an interesting emperical theory on vision. Rather than postulating a visual system that generates a picture of what actually exists in front of the viewer, they theorize that evolution, as well as life experience, has created a visual system in which perceptions represent what a given visual stimulus has typically signified in the past. Admiring the view from a high building, staring at a beautiful woman, shapes, colors, textures, it's basically all the same knee-jerk response... The news release is here, read more about the concept here. Their lab work & results can be found here."

Comments

Looking at prOn...

[darkov]

... it's not exactly a knee jerk reaction...

Honest, Dear

[Zerth]

It's just reflex to look at hot chicks.... I mean, I look at you, don't I.

Somehow that never works.

Syntax vs Semantics

[SmileyBen]

Whilst this article is interesting, and raises some interesting points, they seem to come to some very radical conclusions, based on what can only be called a mistaken belief that vision is 'about' something. They claim that rather than perceiving what is out there, we perceive what we've been trained to see, by past experience individually and of the species.

Well, we can take this two ways. We could say that we've grown eyes and a complete visual system purely based on previous stimuli, in which case it's obvious that new stimuli will only be interpreted in terms of past stimuli. Or we can say that we currently have an apparatus, and despite the fact that something we're immediately seeing might be ambiguous and look like something we've previously seen we could have further sense data that tell us that it isn't what we'd seen before - so what looks like a famous statue could be revealed to just be a photograph of a famous statue when you move around and see that it doesn't change corresponding to how it should.

But either of these interpretations - the past-centric and future-centric ones - are just that, interpretations. They still aren't 'about' anything.

What this article seems to be claiming is that anything you're currently seeing is actually 'about' things in the past, but clearly this isn't true. Vision isn't 'about' anything. When you have a robot with sensors you don't say that when they 'see' an object in their way what they're seeing is 'about' their programming, so they're not actually seeing anything in the present.

Sorry, I'm not putting this very well. Basically I'm trying to say that either their claim is banal - the obvious fact that our eyes are only capable of creating objects in our 'minds' based on things that have been saliant in the past (such as emphasising red objects - i.e. berries - in a green field - i.e. leaves - more that they actually contrast), since obviously our visual system has evolved based on what has been saliant in the past. Or they are making an incorrect claim that current vision is just 'seeing the past' because we don't actually get new ideas from our visual fields, we just try to fit it into previous sets of sense data. The reason that this must be incorrect is that past sense data is no more 'real' no more 'seeing actual objects' than current sense data. So if I see an apple now, it isn't fair to say I only know it's an apple because I've seen apples before because the only sense in which I've seen apples before is the sense in which I'm currently seeing apples. There isn't a 'good old days' when we really saw things, and which we're just reminding ourselves of every time we try to see again...

Re:Syntax vs Semantics

[Bazzargh]

If you program a computer to 'see' (using cameras or whatever) it can tell that two colours in an illusion are the same if they are 'really' the same.

Now do the same to a human. You might /know/ that you are seeing an illusion, but you /cannot/ see the two colours as being the same. Thus the eye isn't a simple camera, and we certainly don't have access to the vision 'bitmap' from the cornea in our concious brain, or we could train ourselves not to see the illusions.

The writeup says that the conventional explanation involves (something like) colour bleed within the neural system to get the effect; for which there is no direct evidence and no explanation for /why/ our eyes would have such a defect (why didn't illusions disappear as we evolved better sight?).

The idea that there might be some evolved preprocessing mechanism at the fundament of our vision which prevents us from seeing like cameras (as opposed to simple 'mechanical flaws') is actually recent and controversial (theres a chapter on exactly this in The Blank Slate thats worth reading), so I don't think it quite qualifies as 'banal'.

The Duke guys don't seem to be quite saying that we see the past at a macro level (leaves, trees, sheep) so much as at a micro level. Something is translating raw colour info into shape, distance and colour /cues/ that we internally reconstruct into the image using past knowledge. This layer is where the visual illusions arise.

Anyway, thats what I thought they were saying, I could have completely misunderstood. It would be more convincing if they could construct a computer model from their ideas that had the same vision defects we do.

-Baz

There was an artile like this

[Unknown Poltroon]

in Discover, or scientific american a while back. It was a bout a man who had been given sight back after losing it as an infant. He went form being blind, to having decent vison at teh age of 40? or so. IT was fascinating reading. Depth perception for him was something he had to think about, optical illusions didnt work. Catching a ball was a new experience. He learned to ski while blind, so skiing with vision was actually harder in ways, he had to lear to interpret what his eyes were telling him, versus what his legs were telling him.

I doubt this will revolutionize anything...

[vidnet]

Why? Because nothing revolutionary has ever had given me the message "Flash error: version 6 or better required."