Concurrent measurement of genital lubrication and blood flow during sexual arousal.

Genital lubrication and blood flow are theoretically related outcomes of women's sexual response that prepare the genitals for sexual activity. Despite its importance for sexual function, few experimental studies have directly assessed genital lubrication or empirically demonstrated how genital lubrication and blood flow relate during sexual arousal. In this study, 36 women viewed stimuli that varied by sexual activity intensity (nonsexual, low-intensity sexual, and high-intensity sexual) while their genital responses were assessed using concurrent measures of genital lubrication (using litmus test strips) and genital blood flow (using laser Doppler imaging). Both measures detected a genital response to high-intensity sexual stimuli relative to nonsexual; however, only the laser Doppler imager was sensitive to varying degrees of genital response elicited by stimuli of different sexual activity intensities. The two measures of genital response were suitable for repeated measurement within a single session. Genital lubrication and blood flow were positively correlated for the high-intensity sexual stimuli. Implications for the assessment of women's genital response and understanding women's sexual arousal are discussed.