Research published in PLOS One suggests that non-invasive brain stimulation could help alter people’s responsiveness to sexual rewards.
The study of 20 very sexually active men and women found that theta burst brain stimulation could increase or decrease the participants’ desire for a sexual reward. Continuous theta burst stimulation increased the participants’ anticipation of sexual stimulation, while intermittent theta burst stimulation decreased their anticipation. The responses to sexual rewards in the lab predicted the number of orgasms they experienced over the forthcoming weekend.
PsyPost interviewed the study’s corresponding author, Nicole Prause of the University of California at Los Angeles (UCLA). Read her responses below:
PsyPost: Why were you interested in this topic?
Prause: Transcranial magnetic stimulation (TMS) had been shown to alter the excitability of brain networks involved in processing primary rewards in research on depression. These are known to be active during processing of visual sexual stimuli (ie., “porn”). These data suggested that TMS also should be able to alter responsiveness to sexual stimuli. We added two important pieces. (1) We tested actual primary sexual stimulation (genital stimulation) rather than secondary rewards (sex films) and contrasted them with other secondary rewards (money rewards). (2) We used theta burst stimulation, a form of TMS, which other scientists had demonstrated can increase or decrease neuronal thresholds depending on the stimulation pattern used.
What should the average person take away from your study?
This study suggests that brain stimulation may be useful to alter how much people respond to primary rewards, including sexual rewards. Since repetitive TMS has shown semi-permanent changes in other domains of study, this could ultimately be useful to semi-permanently improve the lives of some people with low sex drive or high sex drive.
Are there any major caveats? What questions still need to be addressed?
The two major limitations are the control and sample size. We chose to contrast excitatory versus inhibitory TMS for the first study, rather than choosing one or the other to control with a no-stimulation placebo control. We tested 20 men and women who reported problems with higher sexual responsiveness.
Is there anything else you would like to add?
This is the first publication we are aware of that published brain stimulation altering primary rewards. Many laboratories choose weaker secondary rewards such as points or porn to study reward processes. This study provides a citation that others may use to study actual, strong primary rewards in the laboratory.
The study, “EEG to Primary Rewards: Predictive Utility and Malleability by Brain Stimulation“, was also co-authored by Greg J. Siegle, Choi Deblieck, Allan Wu, and Marco Iacoboni.