How did we evolve this?

[visceral_instinct]

We have an eye that actually sees images upside down, and a brain that can then flip the image upright again.

How did we evolve this? I doubt that more primitive animals saw everything upside down then at some point developed a brain that could invert the image again.

 

[spidergoat]

What difference does it make? Our brain doesn't know it's orientation in space.

 

[Dywyddyr]

We have an eye that actually sees images upside down, and a brain that can then flip the image upright again.

How did we evolve this? I doubt that more primitive animals saw everything upside down then at some point developed a brain that could invert the image again.

Ah, doesn't go quite like that.
We didn't "evolve an eye that sees things upside down" that's actually a property of light and lenses.
There's no way to see things the right way up (without multiple lenses anyway).
So the brain correction probably (must have?) happened at much the same time time as the eye evolving.
(Actually, as shown by experiments, the brain compensates rather than "flips" -it's a correction of perception rather than a hard-wired thing).

 

[kurros]

Isn't there some freaky trick psychologists can pull where you hang upside down for a really long time and your brain flips the image again so it looks the right way up? It sounds a bit ridiculous the way I explained it just now so perhaps the details are kind of wrong, but I'd swear I've heard something along these lines at one stage or another.

 

[Dywyddyr]

Isn't there some freaky trick psychologists can pull where you hang upside down for a really long time and your brain flips the image again so it looks the right way up? It sounds a bit ridiculous the way I explained it just now so perhaps the details are kind of wrong, but I'd swear I've heard something along these lines at one stage or another.

They did one where some guy wore a special set of glasses that inverted the image before it reached his eyes, making his eyes "see" it the right way up and therefore went into his brain "the wrong way round".
It self-corrected after a reasonably short time IIRC.

 

[Hercules Rockefeller]

We have an eye that actually sees images upside down, and a brain that can then flip the image upright again. How did we evolve this?

We didn’t specifically evolve this. It’s a fundamental optical property of lenses and light paths – images get flipped upside down. Our eyes merely evolved to accommodate a law of physics.

 

[Dywyddyr]

I said that!

 

[Hercules Rockefeller]

But I've got pictures. :blbl:

 

[visceral_instinct]

Thanks dudes

 

[Michael]

(Actually, as shown by experiments, the brain compensates rather than "flips" -it's a correction of perception rather than a hard-wired thing).

They did one where some guy wore a special set of glasses that inverted the image before it reached his eyes, making his eyes "see" it the right way up and therefore went into his brain "the wrong way round".
It self-corrected after a reasonably short time IIRC.

I would love to read these articles if you happen to have them off hand - or links.

 

[Dywyddyr]

Meh, my mistake.
It doesn't "self-correct" the way I thought it did, i.e. the brain doesn't learn to flip the image again, but the experimenter learned to use inverted images.
So it looks like the brain did evolve to cope with inverted images and it's hard-wired in but the experimenter (and therefore presumably humans in general) can learn to operate and make sense of inverted images.
Section V part B of this gives some details.
And this references this for more depth.
The last being a PDF entitled The myth of upright vision. A psychophysical and functional imaging study of adaptation to inverting spectacles, not exactly snappy, but informative.

 

[Michael]

Meh, my mistake.
It doesn't "self-correct" the way I thought it did, i.e. the brain doesn't learn to flip the image again, but the experimenter learned to use inverted images.
So it looks like the brain did evolve to cope with inverted images and it's hard-wired in but the experimenter (and therefore presumably humans in general) can learn to operate and make sense of inverted images.
Section V part B of this gives some details.
And this references this for more depth.
The last being a PDF entitled The myth of upright vision. A psychophysical and functional imaging study of adaptation to inverting spectacles, not exactly snappy, but informative.

Thanks for that - interesting stuff. What's cool about vision is information from single neurons in the eye can be mapped back, including collateral branching axons, all the way to the thalamus and then to the primary visual cortex and even a bit into the association cortices. Pretty cool.

 

[kurros]

They did one where some guy wore a special set of glasses that inverted the image before it reached his eyes, making his eyes "see" it the right way up and therefore went into his brain "the wrong way round".
It self-corrected after a reasonably short time IIRC.

Haha, ok that sounds like a much more reasonable experiment .

 

[S.A.M.]

We didn’t specifically evolve this. It’s a fundamental optical property of lenses and light paths – images get flipped upside down. Our eyes merely evolved to accommodate a law of physics.

How did our eyes figure out they were seeing upside down?

 

[John99]

Looking at the images in the thread and tbh i was never convinced that we know that the eye does get the image upside down. i believe that much of this comes from human replication and how we would attempt to replicate these aspects of humanity\human condition is different from how nature did it. in this case i dont think it is much more than humans looking at devices like a pinhole camera and just taking it for granted that the human eye HAS to work that way. i would like to see someone here present more solid evidence to corroborate that the human eye sees upside down.

secondly, how do we know how animals see? for example, i have heard 'a cat sees this way..' etc. but lets be hones it is virtually impossible to know how animals see. sure you can look at the eye internally and make some comparisons based on what we DO know but...

the main point of the thread:

i cant answer that.

 

[Dywyddyr]

Looking at the images in the thread and tbh i was never convinced that we know that the eye does get the image upside down.

secondly, how do we know how animals see? for example, i have heard 'a cat sees this way..' etc. but lets be hones it is virtually impossible to know how animals see.

You really love to parade your ignorance don't you?
You make statements like the two above but never ever bother looking something up (in a book or on the 'net).
We know FOR A FACT how eyes see because people have been insanely clever (by your standards) and actually taken an eye and looked at the mechanism. They've even used eyes as "cameras" to see how the light goes through it.

Please, before you post any more, consider thinking if not actually digging through the vast amounts of wonderful information (as opposed to speculation) that is available.

 

[John99]

your overestimating yourself again.

we cut through the BS and are left with:

"We know FOR A FACT how eyes see because people have been insanely clever ([deleted]) and actually taken an eye and looked at the mechanism. They've even used eyes as "cameras" to see how the light goes through it."

it is a lot different than taking apart a http://en.wikipedia.org/wiki/Carburetor for the simple fact that a carburetor is man made device.

looking directly through it would be much more convincing. do you have anything to support that statement?

 

[Dywyddyr]

your overestimating yourself again.

Wrong again.

looking directly through it would be much more convincing. do you have anything to support that statement?

So you missed:

They've even used eyes as "cameras" to see how the light goes through it."

it is a lot different than taking apart a Carburetor for the simple fact that a carburetor is man made device.

Actually it's not. Eyeballs still have to conform to physics.

 

[John99]

dwyder,

you did not produce the proof i asked for. best thing to do is supply a link that supports this assertion and DONT tell me to go look for one.

what i would like to see is an eyeball hooked up to a monitor or perhaps using a mirror behind it to see exactly what the image is.

would that work? no, or at least i would imagine it wouldnt. we are just left to assume the eye and the brain working in tandem to produce useable images but still i fail to see why it is accepted to say the image in the eye is upside down....perhaps it is but this remains to be seen.

 

[Dywyddyr]

dwyder,
you did not produce the proof i asked for. best thing to do is supply a link that supports this assertion and DONT tell me to go look for one.

My apologies.
I assumed (incorrectly it appears) that you'd had, at some point in your life, schooling.
This was explained to us as school children.

what i would like to see is an eyeball hooked up to a monitor or perhaps using a mirror behind it to see exactly what the image is.

Monitors hadn't been invented when these experiments were run, that's why I put the word "camera" in quote marks - that hadn't been invented either. It's part of the history of science.

would that work? no, or at least i would imagine it wouldnt.

Why do you imagine it wouldn't?

we are just left to assume the eye and the brain working in tandem to produce useable images but still i fail to see why it is accepted to say the image in the eye is upside down....perhaps it is but this remains to be seen.

In other words you don't know and therefore assume that no one else does.
As explained: the image is upside down because that's a basic property of light and lenses.