Tag Archives: perception

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 😉



Dialogue in the Dark

23 Sep

As an exhibition developer, I’ve often been asked which has been one of my favorite exhibitions. Few exhibitions have left such a lasting impression on me as the one I couldn’t see.

I didn’t see “Dialogue in the Dark” on a late summer’s day in 1997. As I entered the exhibition boat docked at the Amsterdam harbor, I was thrown from bright sunshine into complete darkness. A voice out of the black introduced its owner: “I am blind and today I am your guide to my world”.

Amidst nervous giggling, stumbling about and bumping against each other, our guide proceeded to lead us through a world devoid of visual stimuli. Disorientation does not begin to describe this unique experience of suddenly being robbed of your major sensory organ. The silly giggling soon gave way to feelings of dizziness, light nausea and wholehearted fascination. We were taken down corridors and into different rooms, asked to touch and identify different objects, to describe the space we were in, and how the objects in it were placed, relative to one another. Things I touched did not make sense at first, as my brain struggled with the unfamiliar task of having to piece together discrete touch sensations, felt consecutively, in order to identify the whole: something our brain normally takes in at a single glance.

We were led into a busy street, where the noise of cars whooshing by, of bicycle bells ringing and car horns honking left me feeling insecure and apprehensive. Would the noises have sounded as threatening and as loud if I could see? There were other sounds I couldn’t easily place without clues from our guide. I realized then how much sight contributes to how and what we hear. Another strange sensation was how often I was mistaken in locating the direction sounds were coming from. During our stroll in the park (birds chirping, dogs playfully barking in the distance) I could have sworn that the sound of water clattering onto marble stones came from my left. I was dead wrong. But what personally surprised me the most was the smell illusions I was having while immersed in this world of darkness. I smelt car exhaust in the busy street; I smelt flowers in the park; I smelt the distinct odor of fresh water clattering to the ground… It was as if my senses were ganging up to compensate for the one I had left behind, with no regard for a reality check.

Towards the end of this tour, all of us were exhausted and in dire need of a drink. Our guide thankfully brought us to a bar (pitch black, of course), where we had to fumble for our wallets and the right coins to pay for our drinks, let alone make sure our fingers didn’t mislead us in counting back the change – for those who only had paper bills. On our way out, we were invited to write a text on a Braille typewriter and take it home, as a memento of this extraordinary exploration of life without light.

Dialogue in the Dark is still successfully touring the world. I highly recommend it.


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