Friday Weird Science: Move over Cosmo, We've got a Vagina Map!!!

Aug 19 2011 Published by under Friday Weird Science, Uncategorized

You know how all those ladies' magazines are telling you how to have mind-blowing orgasms using the same techniques they've been touting for years, usually involving cowgirl and/or trying to revamp missionary as a totally "hot" position (not saying it's NOT, obviously, just it's reputation and all). Well...if you read a lot of magazines on this topic, it may have struck you that most of the advice is...the same. All the same. All based on ideas of how the female genitalia worked. IDEAS. Because very little of this was tested. Most studies of sensitivity in women were actually assumptions based on sensitivity in men, and thus focused almost exclusively on the clitoris (with the idea that the clitoris is basically the male penis, and the vagina is just this hole. Yeah, I know).

Until now. Ladies, we have the new study on which all of Cosmo's articles will be based for the next decade at least. We've got...a vagina map. And a complete FEMALE homunculus.


(I maded you a homunculus)

Komisaruk et al. "Women's clitoris, vagina, and cervix mapped on the sensory cortex: fMRI evidence" Journal of Sexual Medicine, 2011.

As the authors of this paper point out, most of the work described the homunculus has been done in men. The homunculus is a sensory representation of your body, mapped onto your brain. Basically, when someone touches your toe, you "feel" it first in your primary somatosensory cortex, which is at the very top of your head, running in a thin ridge over your skull from ear to ear. Like a headband. A headband of FEELINGS. One of the many cool things about this map is that the amount of cortex you get devoted to a body part is dependent upon how many neuronal inputs that part has. This means sensitive bits, like your hands, tongue, and penis, are going to be huge, while your lower back doesn't get a lot of attention. When you make a model of a human, where all the bits of you are represented by the attention they receive in the somatosensory cortex, you get the kind of grotesque little buddy up there, with huge hands, tongue, and highly well endowed. Well, I guess you know what we're good at. :)

But of course, most of this mapping took place in men. In the original studies, they actually did electrical stimulation on people's BRAINS while awake, going over the somatosensory cortex, and asking where people felt the stimulation, in their toe, the fingers, their chest, etc. Men reported feeling a touch on the penis (isn't it crazy that you can touch someone's brain and they think you're touching their PENIS?!) in the medial region of the paracentral lobule, right near the foot (yes, in your brain, your penis or clitoris is next to your foot).


(Clicky to embiggen)

What we have here is a representation of the homunculus, with a circle showing the paracentral lobule, which represents the sensory map of the genitalia in MEN. When they've done studies on women, they have usually stimulated just the clitoris. Some studies have gotten activation in this area, while others have gotten it a little more lateral, further away from the foot.

So this study wanted to figure out who was right, and it wanted to do the whole deal, not just the clitoris. After all, the vagina isn't just a hole, there's a lot of sensory ability in there, as well as in the cervix. So they got 11 women, put them in an fMRI with their favorite sex toys (according to description, it sounds like they all brought the Rabbit), and had them stimulate themselves in various areas, while they recorded the activity in the brain (sounds a lot better than in other studies, where the experimenter used a toothbrush to stimulate various groin areas. Not particularly titillating for most).

Now, some of you might be aware that I decry a lot of fMRI studies. A lot of them are overblown, based on changes in the brain that don't necessarily correlate with behaviors at all. But this is the kind of study I can get behind. Straight up anatomy, you touch it, and it shows where you feel it. No questions about WHY or whether it makes you more anxious, the data are the data.

And they did get data.

You can see here various areas of the brain with various touches on the anatomy, using the finger and the toe for reference. You can see the finger is really lateral, with arrows toward the sides of the cortex, while the toe is more toward the midline...right near the genitals! You can see the clitoris, vagina, and cervix all get a nice big chunk right at the midline, which places the genitalia in women in the same place as the genitalia for men.

Sure, expected. Never been DONE before, but expected. But then they got something which I was VERY interested to see.

That is NIPPLE stimulation in women. You can see here that there's sitmulation going on in TWO places, one further outward where the chest representation is, and one...right on the genitals. This is the first time I have EVER seen physical evidence for nipple-associated eroticism (of course, they didn't ask the women how they FELT about it). And it makes me wonder if anyone's ever looked at men.

Of course there are the usual caveats. This was self-stimulation, maybe experimenter stimulation would be different, but since they were after a sense of touch here, and not masturbation, I kind of doubt it. And as for Cosmo of the future? To give yourself the earth-shattering orgasms, you just got to rub that brain the right way, and you'll feel it all over.

Komisaruk et al. "Women's clitoris, vagina, and cervix mapped on the sensory cortex: fMRI evidence" Journal of Sexual Medicine, 2011.

11 responses so far

  • amicus says:

    That monkey has nice hands and beautiful long fingers !

  • gerty-z says:

    OK, that is pretty damn cool. Did they have all the women do the same thing in the MRI machine? I am a little surprised that different women wouldn't have some differences in the "size" of different regions on the map.

    • scicurious says:

      Yup, what DM said. There's lots of variability, the maps you see up there just pool it for statistical significance and give you the areas of most activation.

  • DrugMonkey says:

    They do Gertzin, they do. The pretty colors highlight statistically significant voxels (3d pixel), not actual activation. If it's typical of the method, anyway....

  • arvind says:

    Someone should re-write the "My Sharona" song into a "My Vagina" song! It would go great with this piece!

  • telescoper says:

    I feel obliged to point out that "Female Homunculus" is most definitely an oxymoron, being not only derived from the latin word for a man ("homo") but having a clearly masculine ending (-us).

    I recommend Feminuncula, although that does sound rather like a disease.

    • Jeff says:

      Except that homo only means "man" in the "human" sense. For the "male adult human" sense, you'd use vir. Thus "female homunculus" is entirely correct; only if it were "female virellus" would it be incorrect.

      Same thing with the Greek anthropos.

  • Curiouser and curioser says:

    If a woman's nipple is stimulated then the main biological function is not for erotic purposes but for breast-feeding her child and therefore, maintaining the survival of the human species. It could be learned behaviour rather than innate that creates activity in the other area of the brain corresponding with the genital area. Females learn that the breasts are highly erotic to some heterosexual men when they become sexually active and even sexually inactive girls are taught to not let boys touch them there so there's the forbidden aspect to this too.

    • Amoeba says:

      The biologic functions of a cervix and vagina are for babies, too; are those pleasure zones learned? Nipples are damn sensitive in a lot of people and I don't think that has to do with social constructs. I'd place my bets on less-puritanical cultures finding them just as pleasurable.

    • John says:

      If touching the breast instigated the usual female sexual response, then that would involve engorgement of the clitoris, for example, would it not, which should be picked up by the usual touch receptors.

  • Ashley O'Brien says:

    I would add that it is much more complicated than just what area lights up in the brain as to what area it corresponds to..I have known women who have had phenomenal sensual/sexual responses from areas like the small of their backs,and behind their thighs and of course areas like the anus, this I believe is deeply linked to not just neural density as the homunculus map would have us beieve, but deep seated emotional/sexual concepts that may never be completely understood,men, I believe, are far simpler creatures when it comes to pleasure, but women, well, from my experience, I'm almost jealous. the uninhibited ones are just incredible, never have I passed out from overstimulation, but I have had girls who have, and its quite frightening the first time it happens! I thought I'd killed her! she fell off the bed on to the floor then woke up ten seconds later. Definetly one serious ego boost, I can tell you that!

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