A study conducted at the University of California, Los Angeles, has revealed that a person’s brain activity after viewing a sexual image could determine how many sexual partners they have been involved with.

"If your brain responds very strongly even to very tame pictures of sex, then you seem to be easily sexually excited in the real world, too. If we show very explicit sex pictures, eventually everyone's brain responds strongly. It is those weaker images, just hinting at sex, that show the difference," research scientist in the department of psychiatry in the UCLA, Nicole Prause, the Medical Daily reported.

Prause and her colleagues recruited 40 male and 22 female study participants between the ages of 18 and 40. Each respondent was asked to fill out a survey that included the question, “How many partners have you had sexual intercourse with in the last 12 months?" Following the questionnaire, they were shown 225 images that were either non-sexual, pleasant (such as a picture of someone skydiving), neutral (such as a portrait), and sexual (ranging from G-rated to explicit).

Individuals who reported a high number of sexual partners in the questionnaire part of the study also exhibited the same positive potential response to the variety of sexual images.

"This pattern helps tell us why people may choose to pursue new sex partners," Prause added. "For example, some researchers have suggested that people may pursue new partners to experience sexual excitement that they did not experience in their regular lives or with their regular partner."