Changes in the magnitude of the eyeblink startle response during habituation of sexual arousal.

Modulation of the startle response was used to examine emotional processing of sexual stimulation across trials within a session. Eyeblink startle was elicited by a probe (burst of intense white noise) presented intermittently while men were viewing an erotic film segment. Repeated display of the film segment resulted in a progressive decrease in sexual arousal. Habituation of sexual arousal was accompanied by a reduction over trials in the extent the men felt absorbed when viewing the erotic stimulus and by an increase over trials in the magnitude of the eyeblink startle response. Replacing the familiar stimulus by a novel erotic stimulus increased in sexual arousal and absorption and reduced startle (novelty effect), while dishabituation was evident for all three response measures when the familiar stimulus was reintroduced. This pattern of results indicates that with repeated presentation an erotic stimulus is experienced not only as less sexually arousing but also as less appetitive and absorbing. The question of whether habituation of sexual arousal is mediated by changes in attentional and affective processing over trials is discussed, as are clinical contexts in which eyeblink startle can be used in studying aspects of sexual functioning.