Gonadal hormones and effects of partial reinforcement on appetitive behaviour in the rat.

Two experiments are reported in which rats were run in the straight alley with partial (PR) or continuous (CR) food reinforcement during acquisition and then extinguished. Hormone treatment (with estradiol benzoate, EB, or testosterone propionate, TP) was given during acquisition on both CR and PR schedules, but not during extinction. The results showed no effect of EB on the partial reinforcement extinction effect (PREE) in female rats. In males TP was found to reduce the PREE by differentially reducing resistance to extinction in the PR condition. Thus TP but not EB attenuates the behavioural effects of nonreward.