Vaginal & Clitoral Photoplethysmography
This image shows a vaginal and clitoral photoplethysmograph (commonly referred to vaginal and clitoral gauges). The vaginal and clitoral gauges are used to measure women's physical sexual responses. The vaginal gauge is a small, plastic, tampon-shaped probe about 6 cm long and 1.2 cm wide. The instrument has an attachment that also gently rests against a woman’s clitoris. Both instruments are used to measure changes in blood flow within the walls of the genital region. Each instrument has a light source and a light detector; the light source is used to illuminate the region that the light source in contact with, and the amount of blood that is circulating within the walls of that region determines how much light is back-scattered and detected by the light detector. The devices undergo a thorough high-level disinfection process after each use, which is identical to the procedure that hospitals use to disinfect re-useable plastic medical instruments.
Vaginal Photoplethysmography
This image shows a vaginal photoplethysmograph (described above) without the clitoral attachment. This type of vaginal gauge is approximately 5 cm long and 1.2 cm wide. The rubber bar to the left of the vaginal gauge is a placement device, which rests outside of a woman’s vagina to ensure that the gauge is inserted to the proper location in the vagina.
Penile Plethysmography
This image shows a penile plethysmograph (commonly referred to as a penile gauge). Penile plethysmography is used as a measure of physical sexual arousal in our laboratory studies. A penile gauge is a thin rubber tube filled with mercury that measures changes in blood flow to the penis. In a private testing room, participants place the penile gauge on to the middle of their penis. There is a small electrical current running through the inside of the gauge and, as a man develops an erection, an increased degree of stretch in the gauge alters this current. All penile gauges undergo a thorough high-level disinfection process after each use, which is identical to the procedure that hospitals use to disinfect re-useable plastic medical instruments.
Thermography
A thermal imaging camera is used as a measure of physical sexual arousal. In studies using this measure, the thermal imaging camera would be positioned in front of the genital/pelvic region while a participant is seated in their private testing room. The thermal imager remotely detects changes in genital temperature, which tends to increase as an individual becomes sexually aroused. This measure requires no direct physical contact and no identifying information is ever included in the thermal images.
Eyetracking
Eyetracking is used as a measure to assess visual attention. In studies using this methodology, participants view stimuli (e.g., images/films) on the eyetracker monitor while their eye movements are unobtrusively recorded. Using an infrared light source and a camera, the eyetracker records the direction of participants’ gaze, as well as the time spent focusing on a particular location on the screen.