[ChrisMarshallNY]

If you pay attention to cats, you figure out they are fuzzy little “difference engines.” They seem to be hyper-tuned to things that change.

For example, if I move a small item in the corner of my room, the next time the cat walks in, he’ll go straight to it, and sniff around.

I have a feeling that cat’s eyes have some kind of “movement sensors,” built in. Maybe things that move look red, and most of the background looks grey.

[close04]

Even human eyes have some areas, outside the fovea centralis, that are very sensitive to motion even in low light. In the dark you will see motion out of the corner of your eye but you will only see pitch black if you stare in that direction.

The other part you mention is more interesting, I noticed it too. That must be a mechanism in the brain rather than the eye. It’s like the cat keeps a “snapshot” of that place to compare against next time it comes by. This might also explain why they take the same route all the time, maybe it gives them a good reference against the old snapshots.

[ninjagoo]

>> If you pay attention to cats, you figure out they are fuzzy little “difference engines.”

> That must be a mechanism in the brain rather than the eye

Check out "A Thousand Brains: A New Theory of Intelligence" [1] by Jeff Hawkins [2], of PalmPilot fame. This theory postulates, in part, and with evidence, that brains are continuously comparing sensory input and movement context with learned models. I found the book to be mind-blowing, so to speak ...

[1] https://www.amazon.com/Thousand-Brains-New-Theory-Intelligen...

[2] https://en.wikipedia.org/wiki/Jeff_Hawkins