Science of sex

It's not just the pleasure principle driving this research, says Julia R. Heiman, director of the Kinsey Institute, a nonprofit organization at Indiana University. Sex is an important part of human relationships, she says, which in turn can affect psychological health. "An awful lot of illness, or treatments for illnesses, interfere with people's orgasms," she says, including multiple sclerosis, cancer, Parkinson's disease, depression and diabetes.

Indeed, if surveys are to be believed, this most delightful of experiences is elusive for many. About 43% of women and 31% of men in the U.S. between ages 18 and 60 meet criteria for sexual dysfunctions, according to a 1999 report on the sexual behavior of more than 3,000 U.S. adults.

Orgasm researchers hope their efforts will help some of these people -- eventually. For now, reports are more likely to include the words "parasympathetic nervous system" than "try this at home tonight."

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A difficult subject

It has never been easy to study any aspect of sexuality, let alone one so erotically center-stage as an orgasm. "Almost everybody is interested in orgasms, but it is also very difficult to start this kind of work," especially in the U.S., says Dr. Gert Holstege, a neurologist at University of Groningen in the Netherlands. "The Victorian time is still not over."

So it's not surprising that some of the most impressive discoveries in the field of orgasm science were stumbled upon by accident. For example, Viagra originally was a drug being tested for treatment of high blood pressure and heart disease.

Other touted aids lack formal proof. No doubt most of the nostrums available from pharmacies or the Internet derive their power from the "oh-please-please-make-this-work" power of the placebo effect.

And though sexologists as far back as Alfred Kinsey have tallied people's orgasmic habits in exquisite detail, only now are researchers beginning to understand how it all works.

Orgasms are difficult to define, let alone reverse-engineer. A few blueprints, however, have already been sketched out. First, stimulating the genitals sends electrical impulses along three main paths -- the pelvic, hypogastric and pudendal nerves. Next, these titillating signals enter the spinal cord at the base of the spine and zip up to brain regions that respond to genital sensations.