Sexual approach conditioning: Tests of unconditioned stimulus devaluation using hormone manipulations.

Contents of learning that result from conditioned-unconditioned stimulus pairings in sexual approach conditioning were explored with male Japanese quail (Coturnix coturnix japonica). Sexual motivation of subjects conditioned to approach an arbitrary stimulus in a Pavlovian sexual conditioning paradigm was reduced by exposing them to a short photoperiod. Decreased sexual motivation resulted in a decline in sexually conditioned approach behavior (Experiments 1 and 2). Responding was restored when subjects were returned to a long photoperiod (Experiment 1) and when exogenous testosterone was administered (Experiment 2). Decreased sexual motivation did not affect food-conditioned approach behavior (Experiment 3). These results suggest that sexually conditioned approach behavior is mediated by a representation of the unconditioned stimulus, which is activated by the conditioned stimulus.