Showing posts with label cat. Show all posts
Showing posts with label cat. Show all posts

Thursday, July 22, 2021

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When I started grad school, one of the first things I did was to adopt a kitten that had been born earlier that summer in the apartment across the hall. Now, 18 years (!?!) later, here is a Eulogy for my Cat, in the form of a couple of cat-related anecdotes from my studies.

In my first year of school I was getting into the science of spatial vision - acuity, contrast, retina, V1, etc. I learned that a cat's visual acuity is like 5x worse than a human's. So, naturally, I figured that everything must look *blurry* to a cat.

See, I lived with this creature, and I would often think, how do things appear to her? I remember walking home late one night thinking about how stars appear to me as points - must they appear to a cat as blurry spots? And I realized that this couldn't be the case.

When I take off my glasses and see a point of light, it looks blurry in that I can see that what should be a point is actually smudged across a region of the visual field. And to see that smudge as a smudge, I must be seeing details within the region it fills.

If something appears as a point, that means that it has no apparent interior. So in fact, the acuity limit is telling us about the spatial resolution of appearance. Some visible thing that's smaller than the acuity limit must appear as a point. 

Without glasses, a point is imaged on my retina in a smudge that's a good fraction of a degree across. But my true visual acuity is in the range of 2 minutes of arc; so I see that smudge as an extended, 2d thing. My cat wouldn't see the smudge - she'd just see a point.

Now, years later I'm still making use of that insight, for example when I have argued that peripheral vision can and should look just as sharp as foveal vision - it's for the same reasons that a star should look like a point to my cat.

Another one, now about my perspective rather than the cat's. Some version of this is familiar to any of us: you see a dark shadow at night - is it the cat? or is it something else? There was one instance of this that I puzzled over for years.

I had a pair of shoes that I would sometimes leave by the wall in the hallway of my apartment in Boston - now we're in my first postdoc, 10 years ago. Time and again, I would see those shoes out of the corner of my eye and think, "Cat!" - then foveate and see, "shoes!'.

What fascinated me was that after the first time, I knew what was going on. That is, the high-level visual part of me knew they were shoes. But over and over, my early visual system was fooled - that brown shape of a certain size, on the floor, was most likely "Cat".

I started to collect these cases, where peripherally-seen X makes me think I'm seeing Y, even once I know X is really X. I posted an good case here a while back: (https://twitter.com/AndrewHaun3/status/1261891022625398784). But the prototype will always be Shoes->Cat.

Anyways, before I was so theoretically rigid as I am today, I used to wonder: when I thought the shoes were my Cat, did they actually *appear* as a Cat would appear? Did my mistaken recognition subtly reshape the spatial patterns so as to make them a better fit for "Cat"?

It does seem like this sort of thing can happen to some degree, e.g. with Ryota Kanai's "healing grid" illusion. But wholesale, at the object level? How could we find out? It doesn't matter, because I don't think that's what's happening here.

What I think is happening here, rather, is that I am experiencing a spatial form that is shoes-shaped, shoes-textured, etc. And it's decidedly not cat-shaped, cat-textured, etc - it's not clear cut pareidolia, as where I might see the Cat-shapedness of a Cat-shaped cloud. 

With the shoes, they're the right size and location for a Cat, and my super-sensitive Cat-recognizers are activated, and I experience recognition-of-Cat at the same time I experience a shoes-shaped, shoes-textured spatial gestalt. It's not a wholly congruent experience.

Even now, this week, when my Cat is no more, I've already made the mistake of thinking that a shadow in the hall was "Cat"; that a light *thump* in the other room was "Cat". Now, not only is it a mistake, it's an impossible mistake. But the brain does what it does.

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