Every Saturday, The CSPH highlights news or recent research in the field of human sexuality. This week, we’re looking at a study from the Journal of Sexual Medicine that attempts to map sexual activity in the brain, discovering some fun and new nipple facts in the process!
Many past sexology studies have extensively studied patterns of arousal in penis-owners. While there have been a few studies on female sexual arousal, most focus on the clitoris as the primary source of pleasure, and have even successfully mapped out which regions of the brain correlate to clitoral and penile stimulation. This paper, however, tries to reveal a larger picture of female sexuality by mapping the neurological basis for clitoral, vaginal, and cervical stimulation.
Participants in the study were eleven “healthy females” ages 23-56, all of whom were recruited by word of mouth. The study employed a “box car” experimental style in which participants would begin their session with 30 seconds of rest, then 30 seconds of self-stimulation, repeated over five minutes. In addition to stimulating their clitoris and nipple via “rhythmic tapping” from their right hand, participants stimulated their vagina and cervix with a “rounded-top stimulator” that each participant supplied. Experimenters maintained audio contact with the participants, instructing them when to start and stop self-stimulation. Additionally, experimenters tapped participants’ thumbs and toes as a control.
To measure the level of activity each stimuli had on the brain, fMRIs, or Functional Magnetic Resonance Imaging, were used. fMRIs measure brain activity by sensing changes in blood flow and oxygen levels in blood. More active areas of the brain will have more blood flow, and thus need more oxygen to keep working, causing it to “light up” on an fMRI scan.
Researchers used these fMRIs to compare blood flow intensity before and during stimulation. The images showed that responses to clitoral, vaginal, and cervical self-stimulation could all be found in a similar part of the brain, named the “genital sensory cortex” (or, for any neuro-geeks out there, the paracentral lobe). Within this cortex however, the three sensations were localized to three smaller, different areas. This is most likely due to the fact that the vagina, cervix, and clitoris are attached to different nerves, which are also connected to different parts of the brain.
A surprising conclusion of the paper was that stimulation of the nipple not only activated areas of the brain correlating to the chest, but also activated the genital sensory cortex. On top of that, vaginal self-stimulation was also found to activate nipple-connected regions of the brain.This provides an interesting neurological basis to the erogenousness of nipples, and can even explain nipple orgasms.
While the study may not report new information, it is still valuable. For example, it can provide scientific backing to help debunk certain sexual myths, like the idea that vulva-owners can only orgasm with clitoral stimulation. It will be interesting to see if these neurological patterns exist with penis-owners, many of whom also enjoy nipple play. Additionally, it would be useful to study if the responses change with erotic stimuli (like porn) versus physical pressure. Overall, this study provides more evidence that the human body is full of a multitude of nerves, organs, and tissues that can bring pleasure in many different ways to many different people!
