LEARNING THAT FOOD IS INEDIBLE IN FREELY BEHAVING APLYSIA-CALIFORNICA

Freely behaving Aplysia californica can learn that food is inedible. A nimals were given access to seaweed tied into canvas and attached to a force transducer. Animals repeatedly found the stimulus, attempted to ingest it, and failed. The force transducer provided an objective rec ord of the number of attempts made by the animal to ingest the stimulu s, the length of each attempt, and its intensity (i.e., peak force exe rted). Within 2.5 hr, animals showed significant declines in these 3 m easures of response to the stimulus. When exposed to the same stimulus the next day. animals showed more rapid declines in responsiveness. w hich indicate a retention of learning. Training appeared to be specifi c: Responses to the seaweed Laurencia of animals previously trained on the seaweed Ulva do not differ from the responses of naive animals to Laurencia.