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jsshouldbeworking t1_iwurz22 wrote

To understand the way they "see" things, you can re-frame what you think eyes "do."

Eyes take what is in the world and translate it into something the brain can understand. Chameleons probably perceive the world just as the world is--their brain makes a map of what is 'out there' based on the light that falls on their eyes.

By the way, you own eyes do the same thing. You don't see the "input" to your eyes. You see the map of the world that your brain makes from the input. For example, you don't "see" your nose, even though it takes up a bunch of visual space in each of your eyes' visual input. (Close one eye and look for your nose to check!)

You also don't see details in the world except for a tiny fraction of your vision (the "fovea" in the center of your visual field). Want to check: hold your hand out at arms length and look at your fingernail and without moving your eyes, try and describe any detail on one of your other fingernails. You will likely discover that you can't. You cant even see details a few inches from what you are looking at. Whenever you look at something, you are looking with your fovea. Everything else outside of the fovea is "blurry" and much less colored. You mind fills in the blanks and you end up perceiving the world as clear an detailed.

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SkyKnight34 t1_iwv1rmp wrote

This is really good. I think depth perception is another good thought experiment that illustrates this. Imagine explaining to a chameleon how we use the differences in parallax between each eye to estimate depth. We're not consciously doing trigonometry to determine how far away things are, we can just tell. It's baked in to the map of the world our brain generates from the signals.

Chameleons moving their eyes independently is the same for them, it just looks normal. Their brains are adapted to process a different variety of signals than ours. It's just hard for us to "picture" it, since our vision has some different underlying assumptions built into it. But ultimately, it's probably a decent assumption to imagine that they "see things" the same way we do, just with a worse depth perception and a wider field of view.

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jsshouldbeworking t1_iwvhp1y wrote

Yes!

And if you have ever seen a skink/chameleon/lizard bounce up and down (looks like doing pushups), they are doing the same thing that we do with our two eyes. They move their head to two different positions, and use the paralax to figure out what is in the 'depth' dimension. (Some people also say that they do this in courtship or for displays of dominance, which could also be true.)

It's like the GIFs that alternate between two perspectives to show depth, like this

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dupe123 t1_iwvnd7e wrote

In spanish, pushups are called lagartijas, which comes from the spanish word for lizard (lagarto).

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VivendusMoriendumEst OP t1_ixkmsbc wrote

I'm in an extra different situation in a way. I'm aphantasic (can't imagine/picture/recall visual stuff, nor taste, smell, touch, or otherwise, though my faculty with audio is extraordinary and from what I can tell far beyond typical (I'd trade some for vision tho...)

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SkyKnight34 t1_ixkrjgs wrote

It's so fascinating how our brains have such a variety of abilities, isn't it? It makes me wonder how it affects the way we function in general. Like I know that the way I think and conceptualize things is strongly informed by visualizations. And I'm sure that visualization lends itself more toward certain concepts than others, by its nature. It seems like you probably do the same thing with audio, and I'm sure that that lends itself more naturally toward a slightly (or maybe significantly) different set of representations and ideas. It's just so interesting to consider how we're both looking at the same world through these two different lenses, and probably notice very different things about the world because of it.

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aggasalk t1_iwwk6lt wrote

> Everything else outside of the fovea is "blurry" and much less colored. You mind fills in the blanks and you end up perceiving the world as clear an detailed.

I'm sorry, but you have hit a nerve... This stuff is not really true. It gets repeated over and over again (including, sadly, in undergrad psych and even perception classes...), but.. peripheral vision supports color vision just as well as foveal vision (in fact, better in some ways: there are no S-cones in the fovea!).

And "blur" is a very vague term here. Peripheral vision has lower resolution. But it has a precise resolution, and you see things at that resolution, exactly as you do foveally. But we don't say foveal vision is "blurry", even though it has limited resolution just as the periphery does.

You can see smaller details foveally than you can see peripherally, that's the right way to think of it. But things can appear sharp (or blurry) in fovea or periphery.

e.g. see:

http://anstislab.ucsd.edu/files/2012/11/1998-Peripheral-acuity.pdf

https://journals.sagepub.com/doi/full/10.1177/2041669515613671

https://core.ac.uk/download/pdf/82257353.pdf

https://academic.oup.com/nc/article/2021/1/niab006/6290438

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jsshouldbeworking t1_iwxsfal wrote

Thank you for the references! It's good to have more precise ways of talking about the drop in acuity.

Yes, "blurry" is a vague term. To do all of vision in 2 paragraphs, some things get glossed over.

Sorry I hit an optic nerve. ;-)

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A_Notion_to_Motion t1_iwvg3o0 wrote

>You see the map of the world that your brain makes from the input

Which totally makes sense and doesn't seem strange at all until you start thinking about it as an actual image. When I open my eyes I see the world around me, that tree over there is an actual tree that I'm staring at from a distance. But in another sense it's not the world out there at all but an image of it. So that tree over there is actually an image of a tree "right here". In fact everything we see is an image that is made "right here" next to all the other images that we make. But where exactly is that image? What is it made of, how big is it?

So many weird questions come up when thought about from that perspective.

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louploupgalroux t1_iwvqvn9 wrote

I remember my city's science museum had an exhibit on optics. There were goggles you could wear that would simulate eyes of different animals while you walked around some obstacles. It took some time to get used to.

The horse goggles were really trippy. Couldn't see in front, but could see wide on the sides.

Fun project for any DIY scientists out there that want something neat to bring to parties.

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VivendusMoriendumEst OP t1_ixkn5f1 wrote

Uh TBH I'm specifically about those goggles though field of view and stuff can be simulated I'm a bit unconvinced we really understand animal (or even human) senses and qualia that well, but cool exhibit!

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Micahzz t1_iwvveja wrote

The Kantian idea of transcendental idealism describes this pretty well in my opinion.

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WalkerBRiley t1_iwvs8hp wrote

> You cant even see details a few inches from what you are looking at.

I mean this is untrue for the most part. I can tell you the hat on the stand twelve inches to the left of my focal point is blue. The lunch bag further is black. I can tell you what's on my other monitor.

I can't give you words or tiny details but to say I can't 'see any details' is just false. Our peripheral vision does a really good job at constructing a basic idea of our surroundings even when not focused on them. We'd never have survived if it didn't.

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Sharlinator t1_iwwjwgr wrote

Eh, that's just arguing about semantics, using a different definition of "details" than the GP. And note that many of the details you see in the periphery, your brain simply reconstructs from having previously looked there (and indeed continuously and subconsciously moving your eyes in saccades, collecting a patchwork of detailed information for the brain to stitch into a whole), including colors. You'd be surprised how many of the colors you see in the periphery are entirely filled in by the brain.

From a survival perspective, our peripheral vision mostly needs to do one thing and it indeed does it well: detecting moving things. The moment there's unexpected motion detected, we instinctively shift our gaze there to take a better look with the foveal part of the retina.

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badgerj t1_iwxiw67 wrote

Thanks. That was really cool and insightful. Even as a Scientist, this was really well done! Take this!

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