In recent years, there has been a growing acceptance of sexual behavior as a legitimate area of research. An impetus for research utilizing erotic visual stimuli was supplied by the Presidential appointment of the Commission on Obscenity and Pornography (1963). Research into the effects of erotic visual stimuli has typically employed male subjects (Neiger, 1966). The paucity of adequate research has not been a deterrent to the formulation of strong opinions regarding the nature of female sexuality. The present research has focused on female responses to visual representations of the nude male figure.

Vaginal photoplethysmography was utilized in combination with standardized sleep-recording procedures to investigate changes in vaginal pulse amplitude (VPA) during both waking and sleeping conditions in low- and high-arousability females (n = 10 per group), as classified by the Sexual Arousability Inventory. Based upon previous research, it was predicted that both groups would exhibit similar mean levels of VPA during waking exposure to erotic stimuli and during various stages of sleep. Despite hypothesized physiological similarities between groups, the low-arousability group was expected to subjectively report less arousal during the waking erotic conditions.