“Sex is more exciting on the screen and between the pages than between the sheets,” said Andy Warhol. It seems America agrees: adult entertainment is an estimated $10 billion dollar industry in the U.S., though the ethics of capturing and manufacturing sexual desire on screen have been debated for decades. Criticisms abound, ranging in tone and degree of plausibility from you'll go blind! to larger questions of whether watching porn is linked to violent behavior, sexism, or a lack of self-actualization. ("He's just not that into anyone," quipped a New York Magazine article on the supposedly low libido of the Internet generation).
But what really goes on in a brain-on-porn? In a recent study conducted at the University of Groningen Medical Center performed PET scans on the brains of 12 pre-menopausal women, measuring differences in regional cerebral blood flow (rCBF) in the primary visual cortex as the women watched three videos. One video was a documentary on Caribbean marine life, and the other two were "women-friendly" porn films depicting foreplay, manual stimulation, oral sex, and vaginal intercourse.
The researchers found that viewing pornography lead to a decrease in the amount of blood sent to the visual cortex, the part of the brain that processes visual stimuli. This is, of course, the exact opposite of what happens when we watch television or read a blog. Unlike with the blog or the TV show, the brain doesn't take in all of the visual details of a sex scene, and the more explicit the video, the less blood is sent to the visual cortex. (Looks like there's something to the "you'll go blind" threat, afterall.)
The researchers surmised that the blood was diverted to regions of the brain involved in sexual arousal. "You have to realize that the brain wants to spare as much energy as possible, so if some part of the brain is not necessary at a high level of functioning, it immediately goes down," uroneurologist Gert Holstege told LiveScience.
The conclusions of the study deepen Holstege's claim that humans can either be turned on or afraid, but not both. "If you want to have sex, as a man, you need to produce a safe situation for the woman," he says. If anxiety kills your sex drive, does it follow that orgasms can relieve anxiety? A few studies have hinted that they do, though again, primarily in women.
What's the Significance?
Just as interesting as the researchers's conclusions are their methods. Why look at the brains of women in particular? Until recently, this was unheard of. As Beverly Whipple -- the scientist known for "discovering" the G-Spot -- told Big Think in 2009, women were not even included in such research until after 1993.
"Most of the research that was conducted in terms of human sexual responses was conducted in men and findings were extrapolated to women," says Whipple. "We found out that that doesn’t work because women are different from men." Whipple and her colleague, psychologist Barry Komisaruk, believe that men and women feel orgasms the same way, but there are some distinctions when it comes to the variety of sexual responses (women have more). For instance, many women have the unique ability to "think off," or climax just by imagining sensory stimulation.
Whipple and Komisaruk have developed a technique to explore this new frontier of brain research: they ask women in an fMRI scanner to look at their own brain activity in real time, with the aim of increasing activity in specific regions of the brain just by thinking about it. The question is, what is the difference between moving a finger and thinking about moving a finger? What is the difference between feeling and movement?
Both the University of Groningen study and the work of Whipple and Komisaruk at Rutgers suggest that the social constraints which once prevented us from seeking insight into women's sexuality are slowly fading, giving way to a new era in which the female brain is regarded as just as profound and interesting to researchers as the male brain has been since the 1950's -- and sex is exciting everywhere: on the screen, between the pages, between the sheets, and in the lab.