Ash the cat selects the Kanizsa square stimulus — in other words, the illusion of a square — in a new study in which pet owners provided the data.

Ash the cat selects the Kanizsa square stimulus — in other words, the illusion of a square — in a new study in which pet owners provided the data.

What's more, a new study has found that pet cats will also spontaneously sit inside an optical illusion that merely looks like a square.

And that makes them hard to study in some ways because we are often so reliant on training paradigms and cats aren't very motivated to be trained," says Gabriella Smith, an animal behavior researcher who currently works with the Alex Foundation, an avian cognition lab, and the lead researcher on the study.

She wondered how cats would react to what's known as the Kanizsa contour illusion, which uses four Pac-Man shapes in an arrangement that creates the appearance of a square.

Participants received booklets with instructions on how to print out and cut up paper shapes that could be taped to the floor to create three options: the Kanizsa illusion, the actual outline of a square, and a control that had the Pac-Man shapes facing outwards.

And Blake notes that because cats are so short and close to the ground, they might have seen the shapes on the floor from an angle that made them less likely to perceive the illusion of the square in the same way that much-taller people do

Still, he says, the researchers were aware of the limitations of what they found, and he says this study cleverly exploited pet cats' natural desire to occupy an enclosed space