Chapter 3 - The stimulus control of sexual incentive motivation: Non-human mammals

Abstract

This chapter focuses on simple incentive stimuli of possible importance for sexual behavior in nonhuman animals. Nonhuman mammals may respond to stimuli or to qualities of stimuli that human sensory systems are unable to detect. Some of these stimuli or stimulus qualities may have sexual incentive properties. Two groups of stimuli that are supposed to be of substantial importance for rodent sexual behavior are high frequency sounds and nonvolatile chemicals. Among the most studied of the stimuli beyond the capacities of the human are high frequency sounds produced by rodents. There is some evidence suggesting that these sounds activate sexual approach behaviors in female mice. In rats, data are unclear. The elimination of sound production, by cutting laryngeal nerves, has small and inconsistent effects on copulatory behavior in rats and mice. The role of chemicals acting in the vomeronasal system on sexual incentive motivation and on copulatory behaviors is unclear. Results from experimental studies are frequently contradictory. The most reasonable proposal is that the vomeronasal system exerts no influence on incentive motivational processes, but it may have some marginal role in the control of copulatory behaviors. The sexual incentive properties of several odors have been convincingly established in several mammalian species. Odors are important for initiating approach to a potential mate, but less so for the execution of copulatory reflexes. Airborne chemicals may also produce erection, i.e., sexual arousal, in rats and monkeys, or enhance the release of pituitary hormones in some species. Visual stimuli seem to be unimportant among all mammals except primates.