Why is the world right side up?

[Lorizael]

So, yeah, the image on our retina is inverted, but image is a funny way of saying "pattern of nerve firings." By the time we form an actual visual percept of the data our eyes receive, we see an image that is oriented in a way that corresponds to a non-inverted world. Why is that the case?

I'm not really asking why our brain decided to unflip the image on the retina (because, again, it's just a pattern of nerve firings rather than, say, a photograph), but why our brain decided to construct an image that matches the non-inverted image. It doesn't follow necessarily that we would be confused if the world were upside down, because that would have simply been the way we evolved to see, so it wouldn't be confusing.

I did some digging and found two plausible answers to this question, but I'm interested to see Poly's take.

The harder question is: how does the brain construct a right side up world? But of course, that's the hard problem of consciousness itself, and I don't really expect an answer.

[pchang]

Because Aussies don't rule the world.

[Sava]

http://en.wikipedia.org/wiki/Perceptual_adaptation

[Lorizael]

Unfortunately, that article doesn't explain why right side up is what our brain considers normal, and that's what I'm asking.

[Sava]

well, the organisms whose brain didn't have this feature didn't survive long enough to reproduce

There's the "why" for you.

[Lorizael]

No, it's not, because you have to explain why seeing the world right side up provides a competitive advantage over seeing it some other way.

[Sava]

You need an explanation as to why seeing right side up would be advantageous?

And my statement answers the "why" perfectly.

Why is water wet?

[Lorizael]

Yes. Right side up is only natural and easy and comfortable because we evolved that way. There's no particular reason why it is an objectively superior method of seeing the world.

[Sava]

Yes. Right side up is only natural and easy and comfortable because we evolved that way. There's no particular reason why it is an objectively superior method of seeing the world.

What you see is what you get.

Why the sudden apparent lack of understanding about how evolution works?

[Lorizael]

Vision is a highly evolved feature, and much of how the brain processes visual data is clearly advantageous. Our eyes move constantly, but our brain presents us with a nearly constant picture. We have depth perception because our brain produces an image that is a mix of two separate, slightly different images. All of that makes sense. And with all of those, the advantage is clear.

But what is advantageous about seeing the world right side up? It is essentially an arbitrary coordinate system choice. What is concretely beneficial about this coordinate system as opposed to others? (Or is it not better or worse than another coordinate choice, and the system evolved this way without the influence of natural selection (randomly)?)

[Sava]

"Right side up" is only "right side up" because our brain makes it that way.

I'm detecting a bit of a circular thought process here with you. However, I don't quite understand what you are getting hung up on.

[Lorizael]

"Right side up" is only "right side up" because our brain makes it that way.

That's my point. Why did evolution produce brains that make right side up the way it is and not another way? What is the benefit of us seeing the ground as being "down" and the sky as being "up"?

[ColdWizard]

Gravity.

[Lorizael]

What's the advantage of perceiving things to fall down rather than up?

[ColdWizard]

None. It's merely a pervasive influence.