The behavior system for sexual learning.

In this paper we review and update evidence relevant to formulating a behavior system for sexual learning. We emphasize behavioral rather than neurobiological evidence and mechanisms. Our analysis focuses on three types of responses or response modes: general search, focal search, and consummatory or copulatory behavior. We consider how these response modes are influenced by three categories of stimuli: spatially distributed contextual cues, arbitrary localized stimuli, and species-typical cues provided by the sexual partner. We characterize behavior control by these types of stimuli before and after various Pavlovian conditioning procedures in which the unconditioned stimulus is provided by copulation with a sexual partner. The results document extensive Pavlovian modifications of sexual behavior. These conditioning effects reflect new conditioned responses that come to be elicited by various categories of stimuli. In addition, the conditioning of contextual cues and localized stimuli facilitate sexual responding to species-typical cues. Thus, learning experiences enhance how the species-typical cues of a sexual partner stimulate sexual behavior. These modulatory conditioning effects not only produce significant behavioral changes but also increase rates of fertilization of eggs and numbers of offspring produced. These latter findings suggest that sexual learning can lead to differential reproductive success, which in turn can contribute to evolutionary change.