Another CO3 (Comparative Cognition Conference) has come and gone. Every year, a small (250-ish) group of scientists who study animals (from bees to humans) gathers on the beach in Melbourne, Florida to share snippets of research and make friends with others who share the same fascination with how animals think, solve problems, and perceive the world.
Fish see illusions, just like us
Which blue circle looks bigger? They're the same size. This illusion is called the "Ebbinghaus illusion" and it turns out, even fish are susceptible to this visual trickery. Some fish were trained to prefer large circles, and some to prefer small circles. Their test choice depended on the appearance of the circle in relation to a group of differently-colored, differently-sized circles.