Sexual behavior and responsiveness to sexual stimuli following laboratory-induced sexual arousal

Journal of Sex Research, August, 2004 by Stephanie Both, Mark Spiering, Walter Everaerd, Ellen Laan

Emotion can be construed as fundamentally an action disposition, a tendency to do something (Frijda, 1986; Lang, 1993). In this view emotions serve the satisfaction of goals and generate relevant action (such as fight-flight or approach). Sexual excitement, in this respect, does not deviate from other emotions: It serves to satisfy concerns and generates a tendency for sexual behavior (Everaerd, Laan, Both, & Spiering, 2001). From this viewpoint it follows that sexual excitement should incorporate sexual action tendencies and sexual action. To test this prediction, we investigated men's and women's sexual behavior following laboratory induced sexual excitement.

Laboratory studies on human sexual responses generally include measures of genital arousal and subjective sexual arousal. Overt sexual behavior is seldom measured. However, sexual activity may be a relevant variable to investigate in laboratory studies about sexual motivation. Incentive behavior consists of appetitive and consummatory responses and generally proceeds from the appetitive phase to the consummatory phase (Pfaus, 1999). Measuring appetitive and consummatory sexual behavior following laboratory visits offers the opportunity to study the relationship between physiological sexual arousal, subjectively experienced sexual arousal, and overt sexual activity in men and women. The inclusion of measures of overt sexual behavior in laboratory studies will provide a more complete picture of the generation of sexual action.

Incentive motivation theories state that approach behavior will be activated by appropriate incentives (Agmo, 1999; Bindra, 1974; Singer & Toates, 1987). Bindra (1974) introduced the concept of a central motive state, "a hypothetical set of neural processes that promote goal directed actions in relation to particular classes of incentive stimuli, for example, it promotes food seeking and eating in relation to food, or defensive fighting and escape in relation to a predator" (p. 201). An incentive, it is supposed, guides response selection through the excitatory or priming influence of the central motive state on somato-visceral reactions, consummatory acts, and locomotor and skilled actions. Frijda (1986), in line with Bindra, defines motivation as the elicitation of behavior systems by appropriate external stimuli or thoughts thereof. A behavior system is described as a potential action (a program) or a sequence of potential actions. With respect to sexual responses, this means that sexual motivation and the accompanying feeling of sexual desire arise when an individual interacts with appropriate sexual stimuli or thoughts thereof. Thus, in contrast to the layman's belief that sexual desire is spontaneous and arises "out of the blue," sexual desire is the outcome of the processing of sexual stimuli, although it may be felt and perceived as spontaneous (Basson, 2002; Everaerd et al., 2001).

Interaction with an incentive changes the affective state of an organism. Bindra (1974) already pointed to the similarity of motivational and emotional states. Action tendencies manifest themselves in various emotional response systems, including physiological change, emotional expression, and motivated behavior (Frijda, 1986; Lang, 1993). In addition, incentive motivation models state that motivation is the result of the interaction of the internal state of the organism and relevant stimuli in the environment. The internal state of the organism, like hormonal or other somatic factors and past experience, modulates the responsiveness to external cues. It may be expected that exposure to sexual stimuli can enhance responsiveness to subsequent sexual cues by modulating the internal state. Confrontation with a positive incentive results in activation of reward circuitry in the brain (Aharon et al., 2001; Kampe, Frith, Dolan, & Frith, 2001; Schultz, 1998, 2001). Activation of reward circuitry may result in an increase of attention for incentive stimuli and in an increase of subjective and physiological responses to these stimuli, which may result in a self-amplifying motivational process.

We hypothesized, following incentive motivation and emotion theory, that activation of the sexual system through exposure to a sexual stimulus would generate a tendency for sexual action and enhanced attention for and responsiveness to sexual stimuli. Naturally, a one-to-one relationship between sexual arousal and overt sexual activity is not to be expected. Rather, exposure to a sexual stimulus should activate sexual action tendencies, but regulation processes should affect the expression of these action tendencies. The transition of a state of genital and subjective arousal to the execution of sexual behavior should be mediated by a host of cognitive and affective processes, and the acting-out of sexual action tendencies should be influenced by rules and opportunities for sexual activity (Singer & Toates, 1987).

A number of psychophysiological studies on human sexual responses has shown that exposure to sexual stimuli in the laboratory is an adequate method to evoke genital responses and subjective sexual arousal in men and women (Geer & Jansen, 2000; Laan & Everaerd, 1995a). Sexual behavior, however, is measured in only a few experimental studies (e.g., Fisher & Byrne, 1978; Schmidt, 1975; Slob, Bax, Hop, Rowland, & van der Werff ten Bosch, 1996). Fisher and Byrne (1978) used erotic film and compared subjective and behavioral responses of erotophobic and erotophilic participants. Only erotophobic participants showed an increase in sexual behavior following exposure to erotic film. Schmidt (1975) conducted a series of studies in which male and female participants were exposed to erotic pictures, films, and stories. Sexual feelings, physiological reaction during exposure to the sexual stimuli, and sexual behavior during the 24-hour period following exposure were measured. Both men and women showed a slight increase in sexual behavior compared to the 24-hour period before the exposure. In these studies, all data were based on self-report. Although subjective estimate of physiological reaction was included, there was no (objective) physiological measurement of genital response. Therefore, there was no opportunity to look at the relationship between actual genital response, subjective sexual experience, and behavioral responses. Slob et al.'s (1996) study on changes in sexual arousability over the menstrual cycle, using a within-subjects design, did include genital measures (labium minus temperature). They assessed women's postexperimental sexual desire and activity after exposure to erotic videos. Women tested for the first time in their follicular phase showed higher labium minor temperature in response to the film and reported increased sexual desire and more frequent sexual fantasies during the 24 hours following the experimental session. These data indicate that differences in sexual arousability may be reflected in various components of sexual responding during and following a visit to the laboratory. Unfortunately, Slob et al. only reported the relationship between genital response and subjective sexual arousal, not the relationship between responses in the lab and sexual desire and activity following the lab visit.