Objective: This study was designed to assess female sexual arousal by using a combination of physiologic measures and self-reported level of arousal.
Design: Twenty subjects viewed a 23-minute sequence of randomly ordered relaxation and erotic tapes, both with and without auditory stimulus. The physiologic parameters of vaginal blood flow, galvanic skin resistance, respiration, pulse, and blood pressure, as well as self-reported level of arousal, were simultaneously recorded and correlated with video segments.
Setting: An academic teaching hospital.
Patient(s): The 20 subjects (mean age +/- SD: 24.9 +/- 3.0 years) included Caucasian (10), Hispanic (2), Asian-American (4), and African-American (4) women. All women were screened for normal sexual function with the Female Sexual Function Index (FSFI) and with the Beck Anxiety Inventory and Beck Depression Inventory.
Intervention(s): Randomly ordered sequences of erotic and relaxation tapes with and without sound.
Main outcome measure(s): Physiologic and behavioral data, as well as subjective arousal rating, were acquired. The resulting set of multichannel data was correlated with erotic segments and analyzed for sound vs. no sound and time to maximal physiologic arousal.
Result(s): Four independent variables were found to have beta values that were significantly different from 0: respiration (mean = -0.239, SD = 0.177, range = -0.55-0.09, t = -6.04), VPP (mean = 0.158, SD = 0.37, range = -0.48-0.80, t = 1.91), rVPP (mean = 0.161, SD = 0.35, range = -0.537-0.686, t = 2.075), and erotic marker (mean = 0.582, SD = 0.191, range = 0.16-0.85, t = 13.6). Neither heart rate nor galvanic skin resistance beta values approached significance. Respiration period was correlated negatively with arousal rating, indicating that subjects breathed faster when aroused. Auditory stimuli during erotic segments did not increase subjective arousal, and for both subjective arousal rating as well as VPP measurement, maximal response occurred within 2 minutes.
Conclusion(s): Simultaneous measurement of vaginal blood flow, respiration, pulse, and a variable accounting for the onset and offset of erotic video segments accounts for approximately 50% of the variance in predicting subjective female arousal. Regardless of the presence or absence of audio input, 2 minutes was the average minimum time required to reach maximal arousal in young, sexually functional women.