|Top: The brains of people reporting hypersexual problems show the well-replicated pattern of higher response to images of couples having sex. The same pattern has been observed in those who do not report hypersexual problems.
Bottom: The scatterplot shows how the brain responds more strongly to emotional pictures, including images of couples having sex, 300 milliseconds after they appear. The pattern observed in this study of hypersexuality is the same pattern seen in hundreds of studies of people who do not report hypersexual problems.
UCLA researchers have now measured how the brain behaves in so-called hypersexual people who have problems regulating their viewing of sexual images.
The study found that the brain response of these individuals to sexual images was not related in any way to the severity of their hypersexuality but was instead tied to their level of sexual desire. In other words, hypersexuality did not appear to explain brain differences in sexual response any more than simply having a high libido, says Nicole Prause, PhD, researcher in the Department of Psychiatry and Biobehavioral Sciences. “This finding is important,” Dr. Prause says. “It is the first time scientists have studied the brain responses specifically of people who identify as having hypersexual problems.”
A diagnosis of hypersexuality or sexual addiction is typically associated with people who have sexual urges that feel out of control, who engage frequently in sexual behavior, who have suffered consequences such as divorce or economic ruin as a result of their behaviors and who have a poor ability to reduce those behaviors. But, says Dr. Prause and her colleagues, such symptoms are not necessarily representative of an addiction. In fact, non-pathological, high-sexual desire could also explain this cluster of problems.
The study involved 52 volunteers: 39 men and 13 women, ranging in age from 18 to 39, who reported having problems controlling their viewing of sexual images. While viewing images, the volunteers were monitored using electroencephalography (EEG) to measure event-related potentials, brain responses that are the direct result of a specific cognitive event. The volunteers were shown a set of photographs that were carefully chosen to evoke pleasant or unpleasant feelings, ranging from dismembered bodies to people preparing food, skiing or having sex.
The researchers were most interested in the response of the brain about 300 milliseconds after each picture appeared, commonly called the “P300” response. The P300 response is higher when a person notices something new or especially interesting to them. The researchers expected that P300 responses to the sexual images would correspond to a person’s sexual-desire level, as shown in previous studies. But they further predicted that P300 responses would relate to measures of hypersexuality. That is, in those whose problem regulating their viewing of sexual images could be characterized as an “addiction,” the P300 reaction to sexual images could be expected to spike.
Instead, the researchers found that the P300 response was not related to hypersexual measurements at all; there were no spikes or decreases tied to the severity of participants’ hypersexuality. So while there has been much speculation about the effect of sexual addiction or hypersexuality in the brain, the study provided no evidence to support any difference, Dr. Prause says. “If our study can be replicated,” Dr. Prause says, “these findings would represent a major challenge to existing theories of a sex ‘addiction.’”
“Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images,” Socioaffective Neuroscience and Psychology, 2013