A new McGill University study that used thermal imaging technology for the first time ever to measure sexual arousal rates has turned the conventional wisdom that women become aroused more slowly than men on its head.

"Comparing sexual arousal between men and women, we see that there is no difference in the amount of time it takes healthy young men and women to reach peak arousal," said Dr. Irv Binik, psychology professor and founder and director of the Sex and Couple Therapy Service of Royal Victoria Hospital, which is part of the McGill University Health Centre (MUHC).

Thermal imaging, or thermography, is infrared imaging using thermographic cameras that detect radiation emitted by objects based on their temperature. Because of its usefulness in detecting warm objects in the dark, most people know it as the technology used in night vision goggles for military operations.

Previously, sex researchers have measured arousal with instruments that require genital contact and manipulation. Binik focused thermographic cameras on his subjects' genitals while they watched a montage of material from pornography to horror movies to The Best of Mr. Bean to Canadian tourism travelogues to provide a base of control data. During the arousal experiment, the male and female subjects watched separate sexually explicit films procured from the Kinsey Institute and determined to be sexually arousing to specific genders. They watched the images through special video goggles to minimize distractions.

As the subjects responded, the Binik team monitored body-temperature changes to within a 100th of a degree from a computer in another room. Both the men and the women began showing arousal within 30 seconds. The men reached maximal arousal in 664.6 seconds (roughly ten minutes), the women in 743 seconds – a statistically negligible difference.

"In any experiment on sexual arousal done in a laboratory, there is some distraction," said Binik. "But compared to previous techniques involving invasive measures or electrodes, this is minimally invasive and the same measurements are used for men and women, which makes it very interesting that the data ended up being the same."

Dr. Binik's PhD student, Tuuli Kukkonen, said, "This will help diagnose and treat sexual dysfunction in women, such as female sexual arousal disorder, which is poorly understood." Kukkonen will present a paper on the findings September 30 at the Canadian Sex Research Forum conference in Ottawa. The Journal of Sexual Medicine will publish the paper in its next issue, in January.