Headless Brittle Stars: Learning Without a Brain

Brittle stars, headless marine creatures without brains, have been found to learn through experience and classical conditioning. In a series of experiments, researchers trained brittle stars to associate darkness with food by dimming the lights whenever they were fed. Over time, the brittle stars learned to come out of hiding when the lights went out, even before any food was present. This demonstrates that brittle stars are capable of learning and suggests that they can anticipate food and potentially avoid predators based on their environment, despite lacking a traditional brain.