Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior
Ji-Woo Seok and Jin-Hun Sohn
Frontiers in Behavioral Neuroscience 9, no. 321 (2015): 1–11
Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior
Ji-Woo Seok and Jin-Hun Sohn
Frontiers in Behavioral Neuroscience 9, no. 321 (2015): 1–11
This study compared the brain responses, measured using functional magnetic resonance imaging (fMRI), of 23 men with problematic hypersexual behavior (PHB) to those of 22 non-PHB men when exposed to sexual and non-sexual stimuli. The results showed several key differences between these groups, namely, PHB participants: 1) viewed pornography more frequently, 2) experienced greater sexual desire – both more frequent and higher intensity – in response to sexual stimuli, and 3) showed greater activation to sexual stimuli in the prefrontal cortex and subcortical areas of the brain, functional changes consistent with substance and behavioral addictions.
This study investigated how the brain processes sexual desire among individuals with problematic hypersexual behavior (PHB)1 using functional magnetic resonance imaging (fMRI).2 Premised on previous research on those with substance addictions, the researchers hypothesized that people with PHB were more likely to demonstrate greater sexual desire when shown sexual stimuli than people without PHB, and that their prefrontal cortices (PFCs) and subcortical reward systems would respond differently than controls. The researchers pursued this line of investigation because enhanced desire (i.e., wanting) is strongly associated with addiction and brain imaging studies have demonstrated that substance addiction alters specific regions of the brain.
The subjects were 23 heterosexual males with problematic hypersexual behavior (PHB) and 22 non-PHB heterosexual males (age, education-level, and income-level matched) comprising a control group (CG). PHB participants were assessed via clinical interviews, and those with alcohol, gambling, depressive or other disorders were excluded. All participants completed a questionnaire regarding sexual activity within the previous six months, including frequency of sexual intercourse, masturbation, and viewing of pornography per week.
Subsequently, fMRI scans were taken while participants viewed sexual stimuli (20 photos of naked women and sexual activity) and nonsexual stimuli (20 photos of arousing activities such as water sports activities, celebration of winning victory, and skiing) and participants were asked to rate their level of sexual desire in response to each image. The images were presented randomly for five seconds, with a 7-13 second interval between images to allow participants to return to their baseline state. After completing the fMRI portion of the study, participants were again presented the images and asked to rate the level of sexual desire each image elicited using a 5-point Likert scale.
Findings
This study examined the differences in how men with problematic hypersexual behavior (PHB) responded to sexual photos compared to men without PHB. Results showed that PHB men viewed pornography more frequently per week than non-PHB men, and experienced both more frequent sexual desire and a higher intensity of sexual desire in response to sexual stimuli, compared to the control group (CG).
In addition, fMRI results demonstrated that the PHB group showed greater activation and functional changes when exposed to sexual stimuli in similar areas of the brain as those with substance addictions or other behavioral addictions. These results validate and extend those observed by Voon et al.,7 which found that individuals with compulsive sexual behaviors (CSB) demonstrated heightened reactions to explicit sexual images (wanting) compared to healthy controls (see Research Spotlight on Voon et al. here).
The increased activation of these brain regions in men with PHB is also consistent with Incentive Sensitization Theory (explained in detail here),8 suggesting that sexual cue-reactivity is established after repeated exposure to sexual stimuli. Over time, sensitization to cues – in this case sexual cues (i.e., pornography) – are manifested as intense “wanting” or craving, which is a known feature of addiction.9 Gola et al. used IST to demonstrate that brain responses to sexual pictures among men with problematic pornography use (PPU) show strong evidence that PPU may represent a behavioral addiction.10
This study contributes to mounting evidence that excessive use of pornography is associated with functional brain changes consistent with brain imaging results of substance and behavioral addictions.
1 “Problematic hypersexual behavior” was defined in this study as “the continuous participation in repeated sex acts with no control over excessive sexual compulsivity and behavior despite the awareness of the associated negative outcomes,” 1.
2 Ji-Woo Seok and Jin-Hun Sohn, “Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior,” Frontiers in Behavioral Science 9, no. 321 (2015): 1–11, https://doi.org/10.3389/fnbeh.2015.00321.
3 Seok and Sohn, “Neural Substrates,” 7.
4 Specifically, the right dorsal anterior cingulate cortex (dACC), bilateral thalami, left caudate nucleus, right dorsolateral prefrontal cortex (DLPFC), and right supramarginal gyrus.
5 Seok and Sohn, “Neural Substrates,” 7.
6 Seok and Sohn, “Neural Substrates,” 9.
7 Valerie Voon et al., “Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours,” PLoS ONE 9, no. 7 (2014): 1‒10, https://doi.org/10.1371/journal.pone.0102419.
8 Terry E. Robinson and Kent C. Berridge, “The Incentive Sensitization Theory of Addiction: Some Current Issues,” Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 363 (2008): 3137–3146, https://doi.org/10.1098/rstb.2008.0093; Terry E. Robinson and Kent C. Berridge, “The Neural Basis of Drug Craving: An Incentive-Sensitization Theory of Addiction,” Brain Research Review 18 (1993): 247‒291, https://doi.org/10.1016/0165-0173(93)90013-p.
9 Simone Kühn and Jürgen Gallinat, “Common Biology of Craving across Legal and Illegal Drugs – a Quantitative Meta-Analysis of Cue-Reactivity Brain Response,” European Journal of Neuroscience 33 (2011): 1318-1326, https://doi.org/10.1111/j.1460-9568.2010.07590.x.
10 Mateusz Gola et al., “Can Pornography be Addictive? An fMRI Study of Men Seeking Treatment for Problematic Pornography Use,” Neuropsychopharmacology 42 (2017): 2021–2031, https://doi.org/10.1038/npp.2017.78.