There's a vast amount of research on the harmful effects of pornography, and it's important that this information is accessible to the public. Weekly, we highlight a research study that sheds light on the expanding field of academic resources that showcase porn's harms. These studies cover a wide range of topics, from the sociological implications of pornography to the neurological effects of porn-consumption.
Ventral striatum activity when watching preferred pornographic pictures is correlated with symptoms of internet porn addiction
Authors: Matthias Brand, Jan Snagowski, Christian Laier, & Stefan Maderwald
Published April 2016
Peer-reviewed journal: NeuroImage 129 (2016) 224–232
Previous studies have shown similarities between Internet Pornography Addiction (IPA) and other behavioral addictions, such as higher cue-reactivity and craving on a behavioral level (Brand et al., 2011; Laier and Brand, 2014; Laier et al., 2013).
One theoretical idea that might explain why some people experience a loss of control over their internet pornography consumption is that they search material fitting perfectly with their individual sexual fantasies and desires. Consistent with this, it has been suggested that those users who have certain sexual fantasies, which can be satisfied by internet pornography better than in real world, are at-risk for developing an addictive pornography use (Cooper et al.,2000, 2004). Based on these inspiring findings, it seems very important to investigate neural responses to pornographic material that is consistent with subjects’ sexual preferences compared to pornographic material, which is less sexually arousing though also explicitly pornographic.
The current study investigated these hypotheses with functional magnetic resonance imaging (fMRI) in male heterosexual participants, using a picture paradigm with explicit pornographic material that was subjectively preferred (e.g., showing male-female sexual interaction) as well as material that was non-preferred (e.g., showing male-male sexual interaction) (Laier et al., 2013). We have also included scales assessing depression and interpersonal sensitivity, because these two psychopathological symptoms are considered main correlates of internet addiction (see meta-analysis by Ho et al., 2014) as well as vulnerability factors in recent models on internet addiction in general (Brand et al., 2014b), and IPA or cybersex addiction in particular (Laier and Brand, 2014). We also included further measures for hypersexual behavior, sexual excitation, and socio-sexual contacts, because these measures have also been considered important in previous studies (Kühn and Gallinat, 2014; Voon et al., 2014) and theoretical models on IPA (Laier and Brand, 2014).
We investigated 20 heterosexual males. The final sample consisted of 19 participants (mean age = 25.05, SD = 1.43 years). All participants were right-handed. Subjects performed 120 trials of a picture valuation task and 120 trials of a picture choice task. Across the experiment, valuation and choice trials were run in random order for all subjects. This ensured that performance in one task would not systematically influence behavior in the other task.
All pictures showed explicit pornographic material. We used three categories of pictures, each having twenty different pictures: Sexual interactions between a man and a woman (male-female category, MF), with ten pictures showing vaginal intercourse and ten pictures showing fellatio; sexual interactions between two men (male-male category, MM), with ten pictures showing anal sex and ten oral sex; and sexual interactions between two women (female-female category, FF), with ten pictures showing tribadism and ten oral sex. As in previous studies, all pictures displayed only adult individuals, indoor scenes, and no fetish relevant material (e.g., Laier et al., 2013).
The results indicate specific brain responses to the presentation of preferred pornographic pictures compared to non-preferred pornographic pictures in the ventral striatum, a region associated with reward anticipation (Kühn and Gallinat, 2011; O’Doherty, 2004; Robbins and Everitt, 1996).
Striatum activity has been consistently shown in the context of processing visual sexual material (cf., Georgiadis and Kringelbach, 2012; Gola et al., 2015; Sescousse et al., 2013; Stoléru et al., 2012) and has been linked to dopaminergic activity (Politis et al., 2013). It has also been revealed by Voon et al. (2014) that activity in the ventral striatum while being confronted with the visual sexual material is stronger in subjects with hypersexual behavior compared to healthy individuals.
Our results expand these earlier findings, as we found stronger ventral striatum activity for preferred compared to non-preferred pictures within pornographic conditions and not only when comparing pornographic with non-pornographic material. Even more interesting is the relationship between ventral striatum activity and self-reported symptoms of an addictive use of internet pornography: In different individuals, the neural reaction in the ventral striatum is stronger as more severe symptoms of IPA are present. Symptoms of IPA – measured by the s-IATsex – were the only significant predictor of ventral striatum response to preferred versus non-preferred pornographic pictures in the regression analyses.
By contrast, other variables indicating sexual excitability or hypersexual behavior in general, symptoms of depression and interpersonal sensitivity, or indicators of the intensity of current sexual behavior did not lead to increments in explaining variance in the ventral striatum response.
The internet provides endless opportunities to find pornographic material that fits with individual fantasies. Thus, individuals with specific sexual preferences or fantasies could develop a loss of control over their pornography use, because brain systems involved in reward anticipation respond in particular to those pictures or videos that are more preferred than others. This can potentially result in a vicious circle, whereby neural reward anticipation systems provide motivational drive to find material that fits increasingly better with individuals’ preferences.
This mechanism would remain active, as individuals can never be sure that there is no material on the internet that is close to their personal desire than that currently seen. Several media-specific characteristics are potential contributing factors including convenience and anonymity of pornography use, affordability, accessibility, and the chance to escape from reality, as suggested in the Triple-A-engine by Cooper (1998) and the ACE-model by Young (Young, 2008; Young et al., 2000).
Although this argumentation is speculative so far, we believe that the correlations between ventral striatum activity for the contrast preferred vs. non-preferred pornographic pictures and subjective sexual arousal, as well as symptoms of IPA reported in the s-IATsex, provide initial supporting evidence at the neural level. We therefore agree with previous concepts and models on the important role of anticipation and experience of sexual arousal and gratification in the development and maintenance of IPA (Cooper et al., 2000, 2004; Laier and Brand, 2014; Laier et al., 2013, 2014b; Young, 2008; Young et al., 2000).
These results support a role for the ventral striatum in processing reward anticipation and gratification linked to the subjectively preferred pornographic material. Ventral striatal reactivity was sensitive to personal preferences and explained variation in symptom severity. Thus, mechanisms for reward anticipation in ventral striatum may contribute to a neural explanation of why individuals with certain preferences and sexual fantasies are at-risk for losing their control over internet pornography consumption.