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Comment by bmitc | Hacker News Reader

Very interesting stuff. What I think I find mind blowing is that this is just the tip of the iceberg. This is only treating the eye as if it was a standalone imaging sensor. I wish there was a way that we could understand how other humans and animals actually view and perceive the world in an embodied way. I would imagine that each one of these animals processes their visual information in unique ways, perhaps more unique than their eyes.

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This is very far from understanding how cats actually perceive the world, but it's possible to extract crude images [0] from a cat's lateral geniculate nucleus (the part of the visual pathway between the eye and the visual cortex). The LGN likely does not perform much (if any) role in high level visual cognition (that's reserved for the visual cortex), but it does perform a lot of image preprocessing.

It might just be pareidolia, but IMO that preprocessing results in the human face looking strikingly catlike.

[0] https://www.berkeley.edu/news/media/releases/99legacy/10-15-...

I found the link incredible, and the fact its from 1999 is even cooler. Thanks for sharing

The part where they torture and kill animals is less cool, I guess.

Very cool

> It might just be pareidolia, but IMO that preprocessing results in the human face looking strikingly catlike.

That's mostly because of the low resolution I think; the cat will see more detail.

True - birds process vision very differently than mammals. They're tetrachromats, some species have multiple focal points, polarized vision, things like the woodcock's 360 vision, etc. which are major changes in processing info, but also not only is their visual acuity far more powerful, but their speed at processing input (needed for flight) makes it hard to even imagine what vision is like for them.

https://www.scienceofbirds.com/blog/bird-eyes-and-vision

That is a great link!

This whole thread and the links submitted by folks are also great!

Natural Science is absolutely fascinating; and yet our educational system does a poor job of inspiring us all to its study :-(

It's fascinating isn't it, the way we actually interpret things is truly a whole being greater than the sum of it parts. Mostly I don't think that it would be possible to truly understand how any other creature perceives the world, as our brains form the composite perception of the world from all our different senses both those that pick up external stimuli and then also the way those stimuli are perceived internally through brain/nerve structure, body composition and internal chemistry. I think it would be impossible to truly ever experience the world as anything except you, as there would always be information loss without exactly replicating the physical composition of another entity (human or otherwise). Life really is a pretty wondrous thing

It wouldn't just be visual perception, it would also apply to metaphorical abstractions.

I have a theory that the reason we developed Euclidean plane geometry is because our native experience of space at the time was mostly 2D with some limited 3D extensions.

If we still lived in trees our core geometric model would likely be different. And birds almost certainly have a very different model.

All of the base experiential invariants that we built physics from - temperature, distance, speed, discrete numbers, shape, colour, etc - are extensions and abstractions of our particular sensory and feature extraction systems. They're the important perceptions.

Other species would share some, but not all of them, and others would be unfamiliar. Their version of physics and math would prioritise different perceptions and so look very different.

I still don't understand why when I look at a mirror my left and right is flipped but my up and down isn't. If I hold my left arm out, the person in the mirror holds out his right, but up and down do not get the same treatment. Why?

EDIT: I understand that it's front and back that actually get reversed, but that still doesn't help my understand why we think that left and right are reversed by don't think up and down are reversed

It actually has nothing to do with the mirror. It’s because when you rotate the image to align its ‘front’ direction to your body’s, you naturally perform this rotation about the vertical axis. It is this rotation which has the effect of swapping left and right.

(It may also help here to think of a mirror on the ceiling. Consider: does this also swap left/right, or does it swap up/down instead?)

However I orient myself and the mirror, it feels like there is something special about my left and right according to my up and down. Why would I naturally rotate the object about the vertical axis to align it?

Easy way to consider it, when you look at another human being, you innately understand that their right is your left, so you're rotating your perception of their directions around the vertical axis. The mirror isn't actually flipping anything, the top reflects back from the top, the right reflects back from the right. The "flip" is your brain treating them as a person rotated 180°, not the front of a person as if viewed from behind

Afaik, eyes capture only a tiny bit of the image - the rest is a mental model. Whatever partial data eyes capture, the mind maps to known patterns - face features and the like. So animals may indeed see the same pixels, but perceive something wildly different.

If we can ever get that kind of brain read technology so to speak, it can also finally settle the aggravating and mind bending question of whether your blue is the same as my blue. Wouldn't it be wild if our interpretation of colors were all varied?

We can already use language to measure different color perception!

For example we know that women see more colors than men. Or at least name more. https://www.nature.com/articles/s41599-019-0341-7

And we have experimental evidence that peoples who don’t have a name for a color have a harder time seeing it. https://www.sciencealert.com/humans-didn-t-see-the-colour-bl...

Woah, that second link is mindblowing. I had no idea that whole populations of people could see colors in a way others don't, and vice versa. Thanks.

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