ACTIVATION AND REGULATION OF SEXUAL RESPONSE
Processing of Sexual Information
In a series of studies we conducted in the 1990s [see Ref. (14) for a review], we consistently found that women’s genital response and sexual feelings are not
strongly correlated, and that affect influences sexual feelings. Other studies had similar findings (43 – 45,47 – 49,65). In men, correlations between genital response and sexual feelings are usually significantly positive, suggesting that for men’s sexual feelings awareness of their genital response is the most important source.
A surprising finding from our studies was the ease with which healthy women become genitally aroused in response to erotic film stimuli. When watch- ing an erotic film depicting explicit sexual activity, most women respond with increased vaginal vasocongestion. This increase occurs within seconds after the onset of the stimulus, which suggests a relatively automatized response mech- anism for which conscious cognitive processes are not necessary. Even when these explicit sexual stimuli are negatively evaluated, or induce little or no feel- ings of sexual arousal, genital responses are elicited. Genital arousal intensity was found to covary consistently with stimulus explicitness, defined as the extent to which sexual organs and sexual behaviors are exposed (66). This auto- matized response occurs not only in young women without sexual problems, but also in women with a testosterone deficiency (67), in postmenopausal women (68,69), and in women with sexual arousal disorder (42). Such responses are also found during unconsensual sexual activity (70).
Such a highly automatized mechanism is adaptive from a strictly evolution- ary perspective. If genital responding to sexual stimuli did not occur, our species would not survive. For women, an increase in vasocongestion produces vaginal lubrication, which obviously facilitates sexual interaction. One might be tempted to assume that, for adaptive reasons, the explicit visual sexual stimuli used in our studies represent a class of unlearned stimuli, to which we are innately prepared to respond. These stimuli seem to override the effects of various attempts at voluntary control (71).
Emotional stimuli can evoke emotional responses without the involvement of conscious cognitive processes (72). For instance, subliminal presentation of slides with phobic objects results in fear responses in phobic subjects (73). Before stimuli are consciously recognized and processed, they are evaluated, for instance as being good or bad, attractive or dangereous. According to
O¨ hman (74), the evolutionary relevance of stimuli is the most important prerequi-site for such a quick, preattentive analysis. Perhaps sexual stimuli fall within this category and can they be unconsciously evaluated and processed. A number of experiments in which sexual stimuli were presented subliminally to male subjects showed that this is indeed possible [see Ref. (72) for a review]. Preattentive pro- cessing of sexual stimuli occurs in women as well, but appears to be dependent upon the type of prime. Explicit sexual primes do not lead to priming-effects, but romantic sexual primes do (75). This seems to contradict Ohman’s notion that evolutionary relevant primes can be unconsciously processed. Likely, preattentive processing is not entirely governed by evolution, but partly the result of overlearning or conditioning.
A prerequisite of automatic processing seems to be that sexual meaning resulting from visual sexual stimuli is easily accessible in memory. On the basis of a series of priming experiments Janssen et al. (76) presented an infor- mation processing model of sexual response. Two information processing pathways are distinguished (cf. 77). The first pathway is about appraisal of sexual stimuli and response generation. This pathway is thought to depend largely on automatic or unconscious processes. The second pathway concerns attention and regulation. In this model, sexual arousal is assumed to begin with the activation of sexual meanings that are stored in explicit memory. Sexual stimuli may elicit different memory traces depending upon the subject’s prior experience. This in turn activates physiological responses. It directs attention to the stimulus and ensures that attention remains focused on the sexual meaning of the stimulus. This harmonic cooperation between the automatic pathway and attentional processes eventually results in genital responses and sexual feelings. Disagreement between sexual response components would occur, according to this model, when the sexual stimulus elicits sexual meanings but also nonsexual, and more specifically, negative emotional meanings. The sexual meanings activate genital response, but the balancing of sexual and non- sexual meanings determine to what extent sexual feelings are experienced.
The fact that disagreement between genital and subjective sexual arousal occurs more often in women might suggest that for women sexual stimuli have, more often than for men, sexual but also nonsexual or even negative mean- ings. There is some evidence that sexual stimuli generate negative sexual mean- ings in women more often than in men (78,79). Sexual stimuli evoke mostly positive sexual emotions in men, but a host of other nonsexual meanings, both positive and negative, in women.