The pop psychology section of Barnes & Noble is filled with self-help books that dutifully explain how the brain is the body’s primary erogenous zone. Now researchers have spliced together a series of fMRI images to make a movie that shows the extent to which that clichéd adage rings true. A video, shown on an iPad this afternoon in a poster session at SfN 2011, indicates that more activity exists in the brains of women during "self-stimulation" to orgasm (this is a family blog so we’ll stick with geek speak) than anything short of an epileptic seizure. Barry Komisaruk, a Rutgers University psychology professor, marvels: "It seems to activate all of the major brain systems, which we didn’t know before. I don’t know of any other behavioral process that is so powerful." [Below is a still from the "Brain Symphony" movie, courtesy of Barry Komisaruk.]

The movie, labeled by the researchers in Komisaruk’s laboratory as a "brain symphony" and presented to the press in a book called "hot topics," shows the buildup to orgasm and the subsequent ebbing of activity during a five-minute period. A series of colored lines—each of which represents a two-second “snapshot”—descend down the screen, evolving from dark red (lowest activity) to (white, highest level) as a woman’s brain progresses toward the Big O. Each line is subdivided into 80 columns that represent the left, midline and right regions. (The poster presentation includes scans of six women, though only one was used for the movie.)

The opening sonata begins with activation of the genital sensory projection zone, the paracentral lobule, followed by a cueing of the limbic system (insula, anterior cingulate, amygdala, hippocampus). During the crescendo, other areas join in for the hallelujah: the cerebellum (perhaps because of a change in muscle tension), the nucleus accumbens (a reward and pleasure center), the hypothalamus (spritzer of oxytocin, often misleadingly called the 'love hormone') and even the frontal cortex. Other researchers have found that the frontal area, the executive control center, shuts down during orgasm, perhaps because stimulation was provided by a partner, which might enable someone to simply let go.

At 70, Komisaruk has researched the physiology of the female orgasm for decades and has collected fMRI data on 30 women during the past eight years. By no means does the scanner evoke the ambiance of mojitos and Caribbean sunsets. To keep a woman’s head from moving during climax, she must wear what is called a "thermoplastic, semi-rigid head restrainer," which, if it weren’t a clinical lab implement, might bring to mind something secreted in Torquemada’s toolkit. Nonetheless, Komisaruk has yet to encounter any, uh, problems.

Understanding the normal physiology of orgasm might help address the problem of anorgasmia, the inability to achieve climax and the issues related to female sexual desire, as drug makers have yet to come up with a Viagra equivalent for women. Komisaruk is now doing similar research with men. Stay tuned. Maybe Brain Symphony II will premiere at SfN 2012!