Friday Weird Science: Sex in an MRI, is that romantic or what!

So I was GOING to do a post on Fournier’s gangrene, but considering the way it completely grossed out everyone I showed it to, perhaps it’s not such a good idea. I’d hate for you all to run screaming. So we’re not doing it. If you’re REALLY curious, you can look it up, but I am not responsible for any emotional scarring you may suffer having seen the pictures.
And anyway, I found something better to appeal to all of your dirty minds. Courtesy of Coturnix, who I think got it from Pharyngula who blogged it back in the day. And I’m sure you’ve all always wanted to know what sex looks like in an MRI. Schultz et al. “Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal” British Medical Journal, 1999.

Personally, I’m actually a little more interested in the BRAIN in an MRI during sex (that would be tough though, I guess you’d have to use fellatio or cunnilingus?). Anybody know where I can get a paper on that?
Ah, Sex. Copulation. Fornication. To quote Da Vinci “I expose to man the origin of their first, and perhaps second, reason for existing.” I appreciate this man’s sense of humor. And it was in reference to this:
(hint, the man is the one with the great hair).
Some of the things you may notice if you look closely at the drawing:
1) The semen is supposed to come down from the brain, and
2) The ducts in the womans breasts end in her genetalia
A little odd. But Da Vinci had never dissected a human, human dissection was something that was very anathema in his time.
Of course everyone knows (well, everyone who’s seen or experienced it knows) what male sexual arousal looks like. It’s a little obvious. But women have hidden sexual arousal. And so for many years, no one knew what female sexual arousal looking like. Not only that, people didn’t know what SEX looked like! Does the penis go in straight? Does it bend?
Several researchers worked on this issue. In the 1930’s, one guy put a glass, penis shaped tube in the vagina’s of women who had been sexually aroused (don’t move too much…ow…), and in the 1960’s, other researchers constructed an artificial penis that could imitate coitus (yay penile simulators!). They found that, during female arousal, the anterior (front) vaginal wall moved up and back, and the uterus almost doubles in volume! And these changes disappeared after orgasm. But still, these measurements were taken with a speculum (OW), and so the methods were invasive. So this study used the newest in non-invasive techniques, the MRI.
They used a bunch of couples and three single women (the single women were analyzed for how the vagina and uterus looked without penetration). They checked for partial or complete penetration and whether or not the female orgasmed (whether or not the man orgasmed was, for once, entirely unimportant). Basically, they fit them both in the scanner (missionary), tried to get penetration long enough for the acquisition time (which takes a while in an MRI, esp the old school ones), and diagramed the results.
And here’s what it looked like:
To help orient yourself (I know I was completely confused when I first looked at it), the female spine is on the left, the male spine on the right, and they bracket the picture. In the middle you can see this banana shape thing curving up, and it is banana-shaped because it is, in fact, the banana. The pear shaped thing to the upper left is the uternus.
(Side note: apparently the “g-spot” actually stands for something! It’s the Grafenberg spo, named after the gynocologist who hypothesized its existence. Now that is a legacy. Pity he only “hypothesized” it. Heh. heh. heh.)
One of the things that jumped out at me here is just how much the penis curves when penetration is achieved. Also, the hips don’t come together, the woman’s is usually above the man’s. When the women were sexually aroused but not penetrated, the urterus didn’t change position, it was only during penetration that it moved (probably to make some space). But unlike other studies, the uterus didn’t change size, so it’s possible the previous studies were measuring the change in position. However, during female sexual arousal, the anterior wall of the vagina does move, and moves much more than the posterior wall.
Reading the discussion, I already have a favorite quote: “scanning of the position of the human genitals during coitus gives a convincing impression of the enormous size of the average penis in erection (…22cm)…” Yeah, yeah, we know you’re just trying to make up for something… oh, oh, wait, there’s another one: “we have shown that magnetic resonance images of the female sexual response and the male and female genitals during coitus are feasible and beautiful”. I’m sure they’re referring to the clarity of the MRI, but REALLY, they could have picked another adjective.
Anyway, this was the first instance of sex in an MRI, and provided the first real pictures of what actually happens during sex. Doesn’t it just heighten the romance? Right. Probably not. And honestly, boys, you probably don’t want to think of just how much your penis is bending when you’re doing the deed. Might make you uncomfortable.
Last thing that occurs to me: talk about a challenge for weird places to have sex! Forget on the beach, in a closet, or in your fridge. Have sex in an MRI. No one will be able to beat you at sex-related drinking games.
Schultz WW, van Andel P, Sabelis I, Mooyaart E. (1999). Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal British Medical Journal

19 Responses

  1. If you want the ‘behind the scenes’ of the story – check out the book ‘Bonk’ by Mary Roach?

  2. But Da Vinci had never dissected a human, human dissection was something that was very anathema in his time.

    Now, I can’t tell if da Vinci had made any dissections at the time he drew that particular image, but he certainly spent a lot of time cutting up corpses. Perhaps he can be excused for some inaccuracies, it’s not always easy to figure out where everything goes in all the pipes and wires inside the body, as you yourself note in your description of earlier studies of female anatomy.
    Speaking of which, I think one of the more brilliant instances of Wikipedia humour is in the entry on Douglas cavity: “It is named after the Scottish anatomist Dr James Douglas (1675-1742) who extensively explored this region of the female body. ”

  3. I remember reading this paper when it first came out (and I’m an astrophysicist :-)).
    Iirc, they had to find some fairly petite subjects to squeeze them into an MRI machine, and I’ve occasionally wondered if the profound willy-bend was an artefact of the cramped conditions. Do newer model MRI machines have larger openings and if so I wonder if anybody has tried to repeat the research? It’s got to be a better idea for a xmas party than photocopying your bum.

  4. It’s the whole “don’t move” thing that I would expect to be the big problem.

  5. There is an alternative explanation for the shape of the penis in that picture. It reminds me of a line I heard a few years back about tantric sex. In tantric sex both partners are supposed to be able to meditate in such a way as to allow the male (I only heard about the male female version!) to penetrate the female and then, without moving, to perfectly maintain his erection for several hours until, again without moving, they achieved the ultimate simultaneous orgasm.
    The line was “look, if I managed to maintain an erection for several hours without moving I would expect more than the ultimate orgasm. I’d want the ultimate orgasm, a new car, a two week holiday to Barbados and a pay raise!
    (Yes, I heard this joke in the days before viagra!)
    Still, if the participants had to stop moving for an extended period of time in order to capture the image isn’t there a chance that, well, the excitement levels dro(o)pped?

  6. Sigmund: actually, they all rated their “excitement” as “average”. Go figure.

  7. Isn’t that pretty much the normal shape of an erect penis?
    It looks to me like the part that points up is the whole external part of the penis. The part that’s almost horizontal is the internal/attached part (above the “taint”). Since the latter is attached and can’t change its angle, there has to be a dogleg bend when the former points upward.

  8. MRI scans do make a repetitive banging sound at about the right frequency.

  9. Sci, all these posts about sex lately. You need to get some lovin’.

  10. This was a past Ignobel prize winner.
    You also missed the best paragraph in the discussion:
    We did not foresee that the men would have more problems with sexual performance (maintaining their erection) than the women in the scanner. All the women had a complete sexual response, but they described their orgasm as superficial. Only the first couple was able to perform coitus adequately without sildenafil (experiments 1 and 2). The reason might be that they were the only participants in the real sense: involved in the research right from the beginning because of their scientific curiosity, knowledge of the body, and artistic commitment. And as amateur street acrobats they are trained and used to performing under stress.
    As for your other question, I did see a conference poster on fMRI of male orgasm several years ago. The data looked like it was full of motion artifacts to me. No clue if it was ever published.

  11. As anyone with extensive experience with handling the male aroused organ (ie. about half the population) knows, it is very rigid longitudinally, and completely unbendable downwards (this can make morning bathroom visits rather uncomfortable), but it in fact bends quite readily upwards, with little or no discomfort. These images show a possible reason for that arrangement.

  12. Since the point was more to learn the anatomy of intercourse than to make MRI porn it’s probably ok that the men had to use sildenafil or that nobody had shattering orgasms.
    What I find curious is that no further MRI research seems to have been conducted… or at least presented… or at least presented in non-for-profit-firewalled academic journals in nearly ten years! And yet as other commenters have noted the technology has advanced considerably in terms of both speed of image acquisition and resolution, and in terms of room to move more freely. Understanding of sexual response has proceeded apace as well. But for all the terrabytes of downloadable porn exteriors there’s still not a lot of understanding of what happens internally during sex between actual people (as opposed to performers.)
    There has been some work done with 3D ultrasound imaging (see Mary Roach, for instance) but as yet the resolution hasn’t caught up with MRIs.

    All in all, though, even though I’d really like to see some more current research I’d much rather see a 10-year-old rehash than… well… *anything* about Fournier’s gangrene!

  13. very interesting. i knew of the existence of this paper, but never remembered significantly enough to look it up and read it.
    MRI sex is not really the high art form they’re trying to make it out to be.
    i agree, i’m far more interested in what’s going on in the brain when all this is occurring. but the constraints of MRI make that… challenging.

  14. I had an MRI on a broken foot a few years ago, and I had to remain completely still. How did they deal with that issue in this study?

  15. catgirl: well, first they got the girl aroused, right. Then the got the man in there and did penetration. Then were then told to hold perfectly still for up to 8 minutes while a picture was obtained. Unsurprisingly, most of the men couldn’t do it without some *ahem* pharmacological help.

  16. First, they should do this in one of those new “open” MRIs.
    Second, what the hell was the point, and who paid for this study?
    Third, this would be much more awesome to do in a CT scan – get the 3d image of what it looks like from inside. That would be cool.
    Fourth, where can I get paid to have sex in an MRI?
    and finally, I second the desire to see brain scans instead. I would especially be interested to see G-spot orgasm brain scans (and what the hell, the body too), because I assure you, it is not merely “hypothesized.”

  17. There a quite a few papers describing fMRI brain scans during male and female orgasm. Just search Pubmed for “functional imaging orgasm”.

  18. I would be curious to see that MRI!

  19. i will like tobe like you

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