Tag Archives: control condition

Are cats fooled by visual illusions?

9 Mar

The YouTube video below is doing the rounds. It is of a kitten that supposedly is experiencing the illusory motion in Akiyoshi Kitaoka’s beautiful Rotating Snakes illusion.

Perception and the nature of illusions are my passion. So the question of whether animals, like this kitten, might also experience visual illusions is a fascinating one. Moreover, Kitaoka’s Rotating Snakes is one of my favourite illusions and features in the Illusions Gallery that I developed for the science museum I work for.

rotating snake

Rotating Snakes illusion by Akiyoshi Kitaoka

Although several sites (Boingboing, Popsci, io9) have posted this video, encouraging the public to test this illusion on their cats, they have forgotten an important prerequisite for good science: a control condition.

The fact that the kitten in this video interacts, attacks, teases, and plays with the image is not necessarily evidence that it is experiencing the illusory motion inherent in Rotating Snakes. For such a conclusion, you need to compare the cat’s behaviour to a control condition in which the cat views a similar image that contains no such illusory motion. If it seems uninterested and does not interact or play with the control image, you could infer that the cat might indeed be experiencing the illusory motion in the Rotating Snakes illusion.

Akiyoshi Kitaoka was kind enough to provide such a control image, so now we have the ingredients necessary to test whether cats might be experiencing the Rotating Snakes illusion.

 So, cat owners, help collect data on whether cats are fooled by visual illusions. And please share this post and encourage other cat owners to take part in this experiment.

Here’s what to do:

  1. Click on Kitaoka’s link: http://www.psy.ritsumei.ac.jp/~akitaoka/rotsnakes15e.html
  2. Download and print the first two images of his Rotating Snakes illusion: the first one will rotate in front of your eyes (experimental condition), the second one will not (control condition).
  3. Set your camera or smart phone on <record> and get someone to start filming.
  4. Present the non-rotating version to your cat first, flat on the floor: tape it to the floor so that it doesn’t move around when touched.
  5. Allow a minute and a half of experimenting, then stop.
  6. Now tape and present the rotating version to your cat and film for another minute and a half.

Is there a difference in the cat’s behavior when viewing the non-rotating versus rotating version (more clawing, attacking, playing… like the kitten in the original video)?

Please post your comments and observations here, and preferably a link to your video!

Long live crowd-sourced science 😉

Diana