Summary: The precise location within the somatosensory cortex varies from woman to woman in relation to the effects of genital stimulation. Researchers found the thickness of the genital field within the brain corresponded to the frequency of sexual activity in women.
The exact location of the brain area representing genital touch varies among women. The new research in Journal of Neuroscience also found the region was thicker the more frequently the participants engaged in sexual intercourse.
The somatosensory cortex devotes brain space to detecting touch for each part of the body. But the exact location of the female genital field in this map had been controversial. Previous studies produced conflicting results because of less precise mapping methods.
Knop et al. used fMRI to map the exact representation of female genitalia by measuring the brain’s response to a membrane vibrating over the clitoral region. The study was designed to take great care to avoid any discomfort the participants could experience when targeting such a sensitive body region.
The somatosensory cortex represented the genitals next to the hips, matching the body’s anatomy. However, the precise location varied from woman to woman. The thickness of the genital field varied with the frequency of sexual intercourse, suggesting the region’s structure alters in relation to its use.
These results allow for future studies examining the role of the genital field in healthy sexual function, sexual dysfunction, and especially in the long-term consequences of sexual abuse.
Based on this precise mapping, future work can now potentially target the genital representation for treatment of clinical conditions.
About this neuroscience research news
Author: Calli McMurray Source: SfN Contact: Calli McMurray – SfN Image: The image is credited to Knop et al., JNeurosci 2021
Sensory-Tactile Functional Mapping and Use-Associated Structural Variation of the Human Female Genital Representation Field
The precise location of the human female genital representation field in the primary somatosensory cortex (S1) is controversial and its capacity for use-associated structural variation as a function of sexual behavior remains unknown.
We used an fMRI-compatible sensory-tactile stimulation paradigm to functionally map the location of the female genital representation field in 20 adult women. Neural response to tactile stimulation of the clitoral region (versus right hand) identified individually-diverse focal bilateral activations in dorsolateral areas of S1 (BA1-BA3) in alignment with anatomical location.
We next used cortical surface analyses to assess structural thickness across the 10 individually most activated vertices per hemisphere for each woman. We show that frequency of sexual intercourse within 12 months is correlated with structural thickness of the individually-mapped left genital field.
Our results provide a precise functional localization of the female genital field and provide support for use-associated structural variation of the human genital cortex.
We provide a precise location of the human female genital field in the somatosensory cortex and, for the first time, provide evidence in support of structural variation of the human genital field in association with frequency of genital contact.
Our study represents a significant methodological advance by individually mapping genital fields for structural analyses.
On a secondary level, our results suggest that any study investigating changes in the human genital field must map the field individually to achieve sufficient precision.
Our results pave the way for future research into the plasticity of the human genital cortex as a function of normal or adverse experience as well as changes in pathological conditions, i.e. sexual dysfunction, sexual deviation or sexual risk-taking behavior.