Who's Afraid of the Vagina-Brain Connection?

A curious dialogue has developed with the publication of Naomi Wolf's new book, Vagina: A New Biography, one that seems hellbent on poking holes in her central theme that the connection between the vagina and the brain influences a woman's mood and creativity.

Two advance reviews, one by David Dobbs in Wired Science Blogs, and one by Zoe Heller in the New York Review of Books, take Wolf to task for her reliance on neuroscience to help explain the progressive decline that her lower lumbar and sacral nerve blockage had on her sex life, an effect that clouded over her life in general. It would have been easy at that time for Wolf to construct a socially acceptable and perhaps even politically correct explanation for her lack of desire and passion. But to her utter astonishment, getting her spinal cord repaired restored her to her former self. This experience had a profound effect on her and prompted her to look deeper at how biology -- in this case, the neural reality of her clitoral, vaginal, and cervical sensations -- added desire and passion to her life.

Judging from numerous quality-of-life studies done on men with erectile dysfunction who have had it treated, one could easily argue that the penis-brain connection has a major influence on the emotional and intellectual wellbeing of men. So I must ask why the same would not hold true for a vagina-brain connection?

Wolf's search took her, among other places, to my laboratory. We had been doing research on the role of clitoral and vaginocervical stimulation in the sex and reproductive lives of female rats, work that has been published in high-quality peer-reviewed scientific journals. This work revealed that such stimulation, when applied in the right way, induces a state of sexual reward that conditions place and partner preferences (the latter of which was unexpected in an allegedly promiscuous and polygamous species). Taken together with previous work from my laboratory showing the profound role of dopamine and opioid neurotransmitters in both male and female sexual behavior, and in the context of a more general scientific literature in animals and humans showing that blockade of those transmitters induces varying degrees of an "anhedonic" state akin to depression in which reward does not occur and animals do not focus their attention toward it anymore, it became clear to Wolf that these neurochemicals were important parts of the sexual desire and pleasure systems of the brain. They were activated by clitoral, vaginal, and cervical stimulation, something that had gone missing in action due to Wolf's progressive deterioration of her spinal cord. She was thirsty for knowledge about how those sensations activated the brain. She spent an enormous amount of time carefully making herself aware of the scientific literature on the neuroanatomy and neurochemistry of desire and reward and she and I had numerous discussions about how these things work, and how they can be disabled -- by culture, by experience, by events that ultimately perturb neurons in specific brain networks.

In his review, Dobbs argues that Wolf oversimplifies the role of dopamine, noradrenaline, opioids, and oxytocin. Yet the feelings associated with the decline and resurgence of her sexual self were very real, and I would argue that her take on the role of those neurotransmitters is entirely consistent with current conceptions of their role in, among other things, sexual behavior, feeding, and drug addiction. Heller is more allegorical in her review. She takes Wolf to task for ignoring "common sense and logic" and for "drinking shallow drafts from the fountains of evolutionary biology and neuroscience..." because emotional states like desire, events like orgasm, and the interpretation of pleasure are obviously too complex to be left to anything reductionist. Certainly these are socially constructed at several levels, but there is no denying the reality of Wolf's spinal condition or the way that her sexual and creative feelings came thundering back when the problem was fixed. Is Wolf right in regarding dopamine as the "ultimate feminist neurochemical"? It is certainly unlikely that sea slugs and nematode worms are feminists. But can't we allow an accomplished writer and social critic a little poetic leeway to make a point? If dopamine mobilizes attention to reward, and sexual reward is something that has been elusive for so many women for a slew of cultural and experiential reasons (all of which impinge on the kind of sexual stimulation women learn to allow themselves to make or receive), then the lack of dopamine transmission in the brain in a sexual circumstance would likely lead to disorders of desire, and de facto little or no sexual reward since the person in question would either no longer get herself entangled in a sexual circumstance, or if she did, no longer care if she "spread her legs and thought of England."

Heller should recognize her own glass house before throwing stones. There are more than a few straw men set up in her review. One of the criticisms she levels at Wolf, and is reiterated by Dobbs in his blog, is the "upsuck theory" of orgasm, and how it could facilitate pregnancy. Heller dismisses this as being derived from one study from the 1990s with a single subject. Dobbs suggests that Wolf should have read the literature more carefully. Yet a cursory review of this literature on Pub Med shows papers from Shafik and others that studied specifically this cervico-uterine reflex (sometimes referred to as the "Shafik reflex"). This reflex clearly increases sperm transport into the uterus, and was studied in many women, not just one.

Now, does the cervico-uterine reflex actually influence rates of pregnancy? It could. And it could therefore be a reproductively relevant reason (one of several out there in the scientific literature) to answer the seemingly mysterious question of why women have orgasms. And that is as far as Wolf takes it. Cervical stimulation has long been known in animals to increase sperm transport and induce neuroendocrine reflexes that result in increased prolactin secretion from the pituitary, two essential steps to initiating and maintaining pregnancy. Cervical stimulation occurs during heterosexual sex through mechanical stimulation by a penis and prior to and during orgasm as a "dipping reflex" that is part of a "vaginal tenting" response. Does this make orgasm necessary for pregnancy? Not at all. Nor is Wolf saying so. It simply makes cervical stimulation (and in reality, stimulation of the pelvic nerve) a potentially important promoter of pregnancy. Is orgasm the only reason women have sex? Clearly not. And Wolf does not try to make that case either in her book. Sexual stimulation has many rewards, orgasm being one. Now, saying that, there is no doubt that orgasms feel good and that they are associated in female rats and women with the rush of opioid release in the brain.

Dobbs states that "Neurocritic says he can find little peer-reviewed literature to back Wolf's claims." Really? I am not sure where he looked. As with the Shafik reflex, a simple Pub Med search on the role of dopamine, oxytocin, and opioids in the sexual behavior of rats, voles, monkeys, and humans reveals plenty of peer-reviewed literature to back Wolf's take on the role of these neurochemicals. This is definitely not, as Dobbs states, "quick-dip pop-science." At least Dobbs doesn't doubt my scientific credentials, though he seems to doubt things that I say. In one, he quotes me as saying:

"You could call dopamine the 'cause-effect' chemical." This is quite true at some level or even several levels; the chemical causes things to happen. But what effects does it cause? Wolf jumps from Pfaus's statement, without setting it directly into context, to state in essence that dopamine is the key to "good orgasmic sex."

Wolf did indeed set it into context, at the very beginning of the book, in the description of her odyssey back to nerve function, from sexual stimulation colored dimly grey to the resurgence of orgasms colored like Peter Max posters.

What does dopamine contribute to this? The intense desire that amazing orgasms ride on. Anyone who has ever had great sex in a long-distance relationship knows the cocaine-like anticipation, the breathtaking intensity of that first touch and kiss. That is driven in an important way by dopamine. Rats show homologous behaviors in anticipation of sex, behaviors that we can block with very low doses of dopamine antagonist drugs. We can block opioid receptors with selective drugs that subsequently block the development of conditioned place and partner preferences, essentially blocking the effect of sexual reward. In fact, female rats that have their opioid transmission blocked repeatedly during sex stop wanting to have sex anymore, despite hormone priming that would normally bring them fully into heat. Instead of soliciting and controlling sexual contact with males, sexually nonrewarded females fight and reject the males' advances. Can we conclude then that dopamine is the key to desire, and that opioids are the key to reward? I would think that we could. There is enough pharmacological data from the psychiatric literature on people taking dopamine antagonists as major tranqulizers, or from people suffering depression, to know that dopamine is a major player in desire, and that the opioid rush produced by drugs of abuse, or natural rewards like sex and orgasm, not only feels good itself, but sensitizes dopamine release that augments the subsequent experience of desire and focuses it on the stimuli associated with reward. Thus, when Dobbs states that Wolf is flat-out wrong in her contention that "A woman with low dopamine will have low libido and depression," I must remind him that this is exactly what the literature suggests, especially in a sexual circumstance.

Wolf merges the science of sexual arousal, desire, and pleasure, with her experiences of different types of orgasms and especially the vaginal "goddess complex" that is tapped doing tantric sex. Some may well feel that this is science for the sake of pop psych, after all, how can such a thing be? Let me make an analogy: Is a placebo drug effect "real"? Indeed it is. Scientists have shown that belief in, say, a potential painkiller's ability to reduce pain actually causes neural systems that modulate pain (e.g., opioids) to be activated, thus contributing to a placebo effect that in some people can be as effective as the drug itself. Does this mean that the drug is ineffective? No, only that in some people the physiologic effect belief is powerful. Tantric sex seeks to get people to use their whole bodies as conduits of sexual "energy" in sexual circumstances. We can dismiss this as pandering to the placebo, but some people swear by it because they have transformative experiences doing it. Those are as real as any drug. In the end, everything, from drugs and hormones to priming cues to beliefs, are ultimately the sum of the action of appropriate neural systems. However, cognitive neuroscience still has not solved the problem of why one's conscious and verbal self-appreciation of this is a kind of quantum mechanics goes beyond our understanding of the individual parts (though it is currently very hard to study more than one neurochemically defined part).

As Forrest Gump might have said, "You never know where you are 'til you get there." People that have never had orgasms do not know orgasms... well, until they have one, and then are forever changed. Experience changes people in often profound ways. Our brain allows us to scale our orgasms, as we do the incentive quality of the food we eat, not just as good or bad, but on an interval from say 0 to 10. And we can get really good at knowing when an orgasm is a 1 or 5 or 10. But... give a new lover a try, and the orgasms that result may well transform the scaling, such that he or she cranked it up to 11, or what was previously a 10 is now a 7. Sometimes, the quality can change the perception completely into something entirely new. That is part of what the purveyors of tantric sex are trying to do. And for those in whom it happens, a belief in the power of the procedure comes naturally, despite it being entirely circular. But our brains are wired for circular reasoning. We could not have Pavlovian conditioning without that capability. Conversely, for those who cannot or will not look into the eyes of the tantric teacher for 10 minutes before he states "Welcome Goddess," the experience can be a waste of time and money. It can be worse: one person's aphrodisiac can be another's cause of dysfunction. Cocaine is a great example of that. Understanding how cocaine works does not itself mean that we can predict whether it will aid in great or terrible sex, but it will allow us to place the experience in a context or as a function of temperamental variables that may well make the predictions fall into place.

Unlike Dobbs and Heller, I applaud Wolf's foray into neuroscience and its use in her book. I suspect that any embellishing was done for effect, to sensitize readers to a new and integrative way of viewing our sexual selves, and to call women to sexual action and exploration that is in their control, as it is in my female rats. I am sure that was not an easy path for Wolf to take, intellectually or politically. Like any curious human being, she needed to understand what happened to her. She tried to find enlightenment in a review of the social and political constructions of desire, pleasure, control, orgasm, clitoris, and vagina, but that only took her so far. The rest came from a review of the current scientific literature on how the clitoris, vagina, and cervix are connected to the brain, how their stimulation and orgasm activate the brain and pathways of desire and reward, and from her own subjective sexual reawakening. Adding it to her narrative allows the reader to think beyond restrictive cultural definitions of what women should be feeling sexually, to a growing basic science of how their sexual sensory organs work, how they are connected to their brains, and how individual differences in neural innervation of those organs can lead to differences in how sensations are felt and ultimately interpreted and integrated into their sexual selves. Dobbs states that this drives his dopamine "down into a dark and mostly unsexy dungeon." Fair enough. But to me it only opens up new vistas of wonder and inquiry. Rather than taking the nescient view that a potential vagina-brain connection is something too complex to understand, or worse, a dreaded opening of Pandora's Box, may I suggest that we embrace it, as we do the penis-brain connection, as a new empowerment of knowledge about sexuality.