The use of pornography, while unproblematic for the majority, can grow into addiction-like behavior which in its extreme form is labeled as compulsive sexual behavioral disorder in the ICD-11 (WHO, 2018). The aim of this study was to investigate the addiction-specific reactivity to cues in order to better understand underlying mechanisms in the development of this disorder.
We have used an optimized Sexual Incentive Delay Task to study brain activity in reward associated brain areas during an anticipation phase (with cues predicting pornographic videos, control videos or no videos) and a corresponding delivery phase in healthy men. Correlations to indicators of problematic pornography use, the time spent on pornography use, and trait sexual motivation were analyzed.
The results of 74 men showed that reward-related brain areas (amygdala, dorsal cingulate cortex, orbitofrontal cortex, nucleus accumbens, thalamus, putamen, caudate nucleus, and insula) were significantly more activated by both the pornographic videos and the pornographic cues than by control videos and control cues, respectively. However, we found no relationship between these activations and indicators of problematic pornography use, time spent on pornography use, or with trait sexual motivation.
Discussion and conclusions
The activity in reward-related brain areas to both visual sexual stimuli as well as cues indicates that optimization of the Sexual Incentive Delay Task was successful. Presumably, associations between reward-related brain activity and indicators for problematic or pathological pornography use might only occur in samples with increased levels and not in a rather healthy sample used in the present study.
Problematic pornography use can be conceptualized as an impulse control disorder or alternatively as a behavioral addiction. Stress is an important trigger in addiction, but less is known about the neural effect of stress in problematic pornography use. Therefore, we aimed at investigating the effect of stress during the anticipation and viewing of sexually explicit material while considering person characteristics related to potentially being at risk for developing problematic pornography use.
In an fMRI study (n = 157 men, age: mean = 25.46, SD = 4.11) we used a sexual incentive delay task. A social stress test was used to induce stress in half of the participants. Salivary cortisol was repeatedly measured and person characteristics were considered moderating the effects of cortisol response.
We found no group differences in the neural responses during the anticipation phase, but a higher reactivity to sexual stimuli in the dACC in the stress group. Acute stress activated a pronounced cortisol response, which positively correlated with neural activations in the reward system (NAcc, dACC) to sexual cues. Further, the individual time spent on pornography use moderated the effect of cortisol in some regions of the reward system (dACC, mOFC).
Discussion and conclusions
Our results suggest that acute stress related increases in cortisol can enhance the incentive value of cues announcing sexual stimuli. This might explain why acute stress is considered a trigger of pornography use and relapse and why individual stress response might be a risk factor for developing a problematic pornography use.