Comments on: Cats and optical illusions: Now with control experiments!

By: Cola Johnson

Cola Johnson — Tue, 12 Mar 2013 22:01:00 +0000

Well… I’ve just taken extensive video showing my cat laying on the test and then trying to eat the control. Then she attacked the tiny pieces she ripped off of it. And my other cat tried to attack her by biting her neck during the test.

Um… hm…

By: gmarsden

gmarsden — Tue, 12 Mar 2013 20:01:00 +0000

It looks to me that the non-rotating one has radial lines running straight out from the centre, while the lines in the rotating one form spirals away from the centre (in both clockwise and counter-clockwise directions).

Ah, I see now that this is a result of the offsetting colours. So I would say that it’s not the order of the colours *within* a ring that matters, but the colours shift as you move from ring to ring.

Edit: This was meant to be a reply to jimkirk above.

By: Felicitas

Felicitas — Tue, 12 Mar 2013 15:08:00 +0000

I just tried the circles from the link on my cat. I used the laptop, so he wouldn’t be distracted by paper. He was so unimpressed that it was nearly impossible to keep him in front of the screen, he just didn’t get what I wanted him to do. This is interesting, as he is sometimes distracted by gifs or videos I watch when he is on my lap. He even tried to catch the figure on the screen one or two times. So I would say, he doesn’t notice the optical illusion at all.

By: laurasbadideas

laurasbadideas — Tue, 12 Mar 2013 04:55:00 +0000

Over the weekend, I tried this using Escher’s “Circle Limit With Butterflies” as a control image. One of my cats ignored both pictures; the other ignored the rotating snakes but was fascinated by the Escher painting: http://youtu.be/KzV0k9j_uB8

Tonight I tried using all three pictures (the illusion, the “official” control, and the Escher painting), and my cats didn’t really react to any of them: http://youtu.be/4gOAQRwGVh4

By: Dave Faris

Dave Faris — Tue, 12 Mar 2013 01:24:00 +0000

Oh, I see… I was only focused on the outside ring of each circle. Now that you’ve pointed it out, I see the difference. Thanks!

By: The Rizz

The Rizz — Mon, 11 Mar 2013 21:24:00 +0000

Yeah, only the first one on the page seemed to rotate for me, too.

By: jimkirk

jimkirk — Mon, 11 Mar 2013 21:01:00 +0000

rotating: green white blue.
Non-rotating: green white green, blue white blue

The red/blue one doesn’t rotate for me…

By: Dave Faris

Dave Faris — Mon, 11 Mar 2013 20:59:00 +0000

Hey, so why does one seem like it’s moving, and the other doesn’t? I tried to discern the difference, but I can’t spot it. Same colors, same orientation. What’s the crucial difference?

By: The Rizz

The Rizz — Mon, 11 Mar 2013 20:44:00 +0000

That would cause your cat to both attack and not attack the paper until you opened your eyes.

By: Jorpho

Jorpho — Mon, 11 Mar 2013 19:51:00 +0000

I’ve never actually seen the illusion designed specifically so as not to rotate. At this stage it is rather unnerving seeing something that clearly looks like it should be moving that isn’t moving.

Perhaps next we can have a grid of black squares which definitely do not have any grey squares in between them?

By: doniphon

doniphon — Mon, 11 Mar 2013 18:25:00 +0000

No, no, no…. true double-blind would require you to tape your eyes shut as well as your cat’s.

By: relawson

relawson — Mon, 11 Mar 2013 18:13:00 +0000

I just tried it with both eyes on my cat taped shut. It did not react to either illustration.

By: doniphon

doniphon — Mon, 11 Mar 2013 17:58:00 +0000

Next Step: Double-Blind!

By: theophrastvs

theophrastvs — Mon, 11 Mar 2013 17:44:00 +0000

egads, Ms Koerth-Baker, you ought to be included as a minor author or at least in the acknowledgements (…of the resulting paper)