Their study, published Monday in the scientific journal JNeurosci, further shows that the area of the brain activated during stimulation of the clitoris is more extensive in women who have more sexual intercourse.
It was performed by stimulating the clitoris of 20 women while performing an MRI of their brains.
Does a larger area allow you to better perceive the sensations? Is the size of this area what prompts more intercourse, or does frequent intercourse make it grow? Impossible to say for the moment, specify the researchers.
This work could also help design better treatments for people who have suffered sexual violence or suffer from sexual disorders.
How the female genitals are represented in the human somatosensory cortex is greatly under-studied, explained to AFP Christine Heim, professor of medical psychology at the Charité University Hospital in Berlin and co-author of the study.
This lack of knowledge has hampered research on both standard sexual behaviors and disease states., she added.
When any part of the body is affected, neural activity is triggered in the somatosensory cortex. Each part of the body corresponds to a different area of the brain, forming a sort of body map.
Until now, however, the precise location associated with female genitalia has remained a matter of debate.
Previous studies had sometimes placed it under the brain area associated with the foot, sometimes near that associated with the hip. In question: imprecise stimulation techniques (by oneself, by a partner), causing the simultaneous touching of other parts of the body or triggering an excitation, thus blurring the results.
In 2005, using a technique that mimics a very localized tactile sensation, researchers were able to determine the brain site associated with their gender for men, but this had not yet been done in women.
The method used
To remedy this, 20 healthy women aged 18 to 45 were selected.
For stimulation, a small round object specifically designed for the occasion was applied above the underwear at the level of the clitoris: thanks to air jets, a small membrane began to vibrate slightly.
The approach was intended
as comfortable as possible for the participants, says John-Dylan Haynes, co-author of the study.
Eight stimulations of the clitoris were performed, each of 10 seconds interspersed with 10 seconds of rest, as well as eight stimulations on the back of the right hand for comparison.
However, the precise site varies for each woman within that area.
The researchers then investigated whether this area exhibited different characteristics depending on sexual activity.
The 20 women were asked about the frequency of their intercourse in the past year, as well as since the beginning of their sex life.
Then, for each of them, the researchers determined the 10 most activated points in the brain during stimulation and measured the corresponding area.
We found a link between the thickness of the genital area and the frequency of intercourse, especially in the last 12 months, exhibits Christine Heim.
The more intercourse, the thicker the area.
Development of areas
The plasticity of the brain is well known: some of its parts develop as a function is used. However, no causal link has yet been directly established in this case.
Previous work, carried out on animals, has however shown that stimulation of the genitals of rats and mice effectively leads to an expansion of the area of the brain corresponding to these organs.
Furthermore, the study did not determine whether a larger area resulted in better perception.
However, Christine Heim, in a study published in 2013, had shown that people who had suffered traumatic sexual violence had a reduced genital area.
We hypothesized, at the time, that this could be the brain’s response to limit the harmful effect of the abuse., she explained, specifying that further studies would be necessary to verify it.
In the future, the goal is to develop ways to help patients: the researcher wants to study whether certain sexual disorders are linked to alterations in the genital area. Therapies aimed at
train this area could then be considered.