ABOVE: © KAILEY WHITMAN
A number of optical illusions used in cognition research rely on the perception, or misperception, of differences in size between identical shapes. Researchers use two main types of behavioral experiments to assess dogs’ susceptibility to these sorts of illusions. One way is to train the animals to interact with the illusions on a computer screen, using treats to motivate dogs to pick whichever stimulus they perceive to be larger, for example. The other is to use food—which dogs tend to express interest in without any training—to recreate the optical illusions for a spontaneous (untrained) choice experiment.
Sarah Byosiere and colleagues at La Trobe University in Australia reported an experiment using the above setup in 2016. They found that dogs trained to pick whichever black circle they perceived to be the larger of the two consistently selected the one surrounded by larger blue circles—the opposite effect from ...
