Validation of laser Doppler flowmetry for the continuous measurement of women's genital response.

Laser Doppler imaging is a valid method of assessing genital response, detecting increases in genital blood flow to sexual, but not nonsexual stimuli. Although laser Doppler imaging provides a direct measure of genital blood flow, its discrete perfusion images provide a discontinuous assessment of genital response, limiting some study designs. The aims of this study were to investigate the measurement properties of laser Doppler flowmetry, a direct and continuous measure of blood flow, as well as examine the time course of genital response using flowmetry. A sample of 45 cisgender women attended two experimental sessions wherein they viewed sexual and nonsexual stimuli (e.g., neutral, anxiety, humor) while their genital responses were assessed using laser Doppler flowmetry. As expected, laser Doppler flowmetry was a valid measure of genital response-detecting increases in genital blood flow elicited by the sexual stimuli only-and was sensitive to varying degrees of genital response elicited by low, moderate, and high-intensity sexual stimuli. The measure also exhibited convergent validity with genital response assessed via laser Doppler imaging, test-retest reliability across testing sessions, and internal consistency as well as high sexual concordance with self-reported sexual arousal. Descriptive analyses showed that genital blood flow assessed using laser Doppler flowmetry was highly responsive, with initial, peak, and return to baseline responses occurring within timeframes appropriate for repeated measurement within a single session. Laser Doppler flowmetry is a valid, reliable, and sensitive measure of women's genital response that can be usefully applied in sexual psychophysiology research.