the tabloids missed this story, but the error bar didn't - brain science has found the clitoris! the brain area responding to clitoral vibration is in the middle at the top of the brain, just where it should be.  

original article: Knop et al., 2022 (Journal of Neuroscience), image source

this story was in episode 26 #clitoris #brain #tactile #MRI #mapping

the error bar says

in a rare case of an open-access scientific paper about sex being missed by all the news media, the female clitoris has, at last, been found.

the general anatomy of the brain is not a mystery & has been known about for centuries. in the 1920s to 1950s, the specific anatomy of the brain areas that respond to touch on the body were systematically mapped. there's an area for touch on the hand - i study that one - another for the foot, another for the face.

but the genitals have not been mapped precisely. well, i say genitals, but of course, following international women's day, i mean the clitoris. the penis was properly mapped - with non-arousing stroking of the penile shaft inside the brain scanner - as long ago as 2005, but the first studies of the clitoris came six years later. see what i did there?

the new study asked 25 women to go into a brain scanner with a vibrating dome & 25 minutes to themselves. with a punishing 32 repetitions of 10 seconds of the dome vibrating under their mons pubis, plus another 320 seconds vibrating their hand, science was finally able to find the clitoris in the brain.

the clitoris is, aptly, underneath a fold in the uppermost part of the brain's main & important sensory area - the postcentral gyrus. no great surprises really, apart from that it's not in the place where the penis was located, way back in the 20th century.

has the clitoris been found?


this study & its results are clear & simple - in those women for whom the experiment worked, the area of the brain activated by the clitoral stimulation, as well as the area for the hand stimulation, were neat & precisely-located on the brain. so, job done, right?

well, no. error bar nerds wouldn't be getting their money's worth if i didn't raise a few problems, so here they are.

first, 25 women were recruited for the study - & presumably scanned - but no information other than 'it didn't work' was provided for 5 of them. what happened to those 5? did they not find their own clitoris? did the brain not activate? was it a statistical problem? nothing is given, & that's a problem.

second, a further conclusion of the study was that the self-reported frequency of sexual activity was related to the thickness of the clitoral area on the left side of the brain, but not the right side. this relationship was found only after the analysis included several other factors, for example age, years of sexual activity & whole-brain thickness. it would be good if the authors had reported the analysis without these additional factors, just to be sure.

it also seems that in this extra analysis two additional women's data were excluded. but again - & troublingly - no details are given about these removals. given that this weak, post-hoc relationship was found on only one side of the brain & only after accounting for some other things, i think we can ignore the relationship between brain thickness & sexual activity.


this clear and simple brain imaging study has indeed found the clitoris, but why shroud the results in mystery by excluding 5 & then 7 of the participants in different analyses. some deeper probing is required.