Latent Inhibition of US Signal Value Following CS-US Training
Abstract
Two experiments with rats examined latent inhibition of unconditioned stimulus (US) signal value. In Experiment 1, latent inhibition (LI) rats showed attenuated conditioning, compared to control (C) rats, when a single food pellet, delivered 10 min into a session, was followed by three additional pellets. In preexposure, one pellet had been delivered 10 min into the session (in Group LI), or placed into the magazine at the beginning of the session (in Group C). Experiment 2 replicated Experiment 1 and also showed that latent inhibition of US signal value resulted after conditioned stimulus (CS) - US training. Results from Experiment 2 suggest that, in Pavlovian conditioning, subjects learn a CS-US association and also learn that a US signals a subsequent US-free period. Implications for theories of latent inhibition are considered.