Brotto did a bit of experimenting on herself. Not that she suffered from any disorder, but she talks of herself sometimes in a researcher’s terms as “an n of one,” a single subject on whom she likes to test her ideas. Along with mindfulness, the treatment Brotto’s supervisor devised for borderline personality uses cognitive therapy, which stresses altering patterns of thought to transform self-image and experience. One day at yoga class, Brotto tried the combination. She went through her usual yoga poses, but with “a cognitive reframe,” she said. She told herself, “over and over like a mantra,” that she was an especially sexual woman, “capable of a high level of desire, a high level of response.” And, she recalled, “there was a deliberate intent not only to listen to my body even more than I normally would in yoga but also to interpret the signs from my body as signs of my sexual identity. So my breathing was not just breathing through the pose; it was breathing because I was highly sexual.” Sensation and self-image became linked. She was in a particularly awkward and taxing position, bent over and balanced on one foot and one inverted hand, when she had a profound moment. It wasn’t that anything she was trying mentally was itself so stunningly new. The power of positive thought is a cliché. And the acute concentration on the sensory echoes the sex therapy practiced by Masters and Johnson in the 1960s. Yet through melding the two something revelatory occurred. Suddenly her straining muscles and racing heart were affirmations “of my sexual vigor, my sexual arousability.” She finished class with a thrilling sense of her own body, her own erotic potency.

Brotto took what she learned in treating borderline personality, including the use of raisin exercises to foster mindfulness, and what happened in yoga class, and applied it first with her gynecological cancer patients, then with a wide range of women with weak desire. Her results, published in the leading journals of sexual research, have been promising, with her subjects reporting stronger libidos and better relationships, though there are caveats: that desire isn’t easy to measure; that patients are prone to report improvement on questionnaires given by those who treat them; that almost any method that gets people to think about sex may increase their interest in having it. Brotto is now studying the effects of her group sessions on a sample of 70 women who have or will soon gather in the stark conference room around the pair of beige tables to be led through her program of mindfulness and cognitive therapy. They are sent home with assignments — to observe their bodies in the shower and describe themselves physically in precise and neutral language, in phrases that hold no judgment; and, after another session, to repeat over and over, “My body is alive and sexual,” no matter if they believe it. They are taught about research that shows that belief doesn’t matter, that the feeling will follow the declaration. And they are instructed, in their sessions, to place the raisins in their mouths, to “notice where the tongue is, notice the saliva building up in your mouth . . . notice the trajectory of the flavor as it bursts forth, the flood of saliva, how the flavor changes from your body’s chemistry.”

This exercise is among Brotto’s ways of training patients to immerse themselves in physical sensation. One hope is that such feelings will whisper to the women of their own erotic vitality. Another is that her patients will learn to be aware of the changes in their bodies — automatic reactions similar to salivating — before or during sex. An underlying theory is that while her patients’ genitals commonly pulse with blood in response to erotic images­ or their partners’ sexual touch, their minds are so detached — distracted by work or children or worries about the way they look unclothed, or fixated on fears that their libidos are dead — as to be oblivious to their bodies’ excitement, their bodies’ messages. The skill of fully attending to sensation is essential within Brotto’s vision of women’s desire — a vision that she imparts to her groups partly by introducing a diagram called “the Basson Sexual Response Cycle,” whose circles and arrows have lately been imprinting themselves on the field of sex therapy and helping to guide Brotto’s formulations for the next D.S.M.

he minimalism of the manual’s present criteria for H.S.D.D. —“persistently or recurrently deficient (or absent) sexual fantasies and desire for sexual activity” — seems to presume that the workings of desire are straightforward, that healthy sexual beings are regularly sparked by lust, that they are busy imagining, and wishing for, erotic encounters. Meanwhile the flow chart of women’s sexual experience created by Rosemary Basson, who is Brotto’s colleague at the Center for Sexual Medicine and at the University of British Columbia, with which the center is affiliated, is complex and a bit difficult to describe. Basson, a British medical doctor who has been at the center for more than two decades, was first drawn to the field of sexuality as an internist in England. Assigned to a ward for victims of spinal-cord injuries, a floor, as she remembers it, with a steady supply of men paralyzed in motorcycle accidents, she sometimes found herself with a patient who worked up the courage to ask about how or whether he could ever have sex. She sought out a supervisor for advice and was told, she recounted, imitating the clipped, almost panicked reply, “Change the subject, change the subject.” She has dealt directly with the subject of sex ever since.

“All through the ’90s I was scribbling my circles,” she told me in her wispy voice, as she penned out a diagram for me the way she long has for her female patients. She had on a pale flowing skirt with a pattern of leaves and wore her feathery brown hair cropped above her ears. There was something ethereal about her. Yet she drew with swift authority. A box with the phrase “reasons for sex” went at the top of the page. The beginnings of a large circle ran from one side of the box. And the diagram made clear that desire — at least the way many tend to think of it, as a lust or craving that spurs someone toward having sex — might or might not play a role in making a woman want sex and, in any case, isn’t at all necessary for the sex to be satisfying.

Image Credit... Pomme Chan

A different manifestation of desire — not initial hunger—– appears about two-thirds of the way around Basson’s circle. There, in the diagrams she began publishing in obstetrics and sexuality journals 10 years ago, come the words “responsive/triggered desire.” For Basson, this is necessary to satisfaction. But it comes after arousal starts. So a typical successful experience might proceed something like this: first a decision, rather than a drive, to have sex; next, as Basson puts it, a “willingness to be receptive”; then, say, the sensations of a partner’s touch; next, the awareness of being aroused; then the “responsive desire” along with increasingly intense arousal; and at last the range of physical and emotional payoffs that sex can provide and that offer positive reinforcement leading back to the top of the diagram, to the reasons for setting off on the circle to begin with.