This post lists all the studies assessing the brain structure and functioning of Internet porn users. To date every study offers support for the porn addiction model. The results of these 22 studies are consistent with 150+ Internet addiction brain studies, many of which also include internet porn use. All support the premise that internet porn use can cause addiction-related brain changes. A review of this research, Neuroscience of Internet Pornography Addiction: A Review and Update, authors stated:
Below are the studies:
Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) -
A German fMRI study which found 3 significant addiction-related brain changes correlating with the amount of porn consumed. It also found that more porn use correlated with less reward circuit activation while viewing sexual photos. Researchers stated their findings indicated desensitization, and possibly tolerance, the need for greater stimulation.
Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours (2014) -
The first in a series of Cambridge University studies found the same brain activity as seen in drug addicts and alcoholics. It also found that porn addicts fit the accepted addiction model of wanting "it" more, but not liking "it" more. The researchers also reported that 60% of subjects (average age: 25) had difficulty achieving erections/arousal with real partners, yet could achieve erections with porn.
Enhanced Attentional Bias towards Sexually Explicit Cues in Individuals with and without Compulsive Sexual Behaviours (2014) -
The second Cambridge University study. An excerpt: "Our findings of enhanced attentional bias... suggest possible overlaps with enhanced attentional bias observed in studies of drug cues in disorders of addictions. These findings converge with recent findings of neural reactivity to sexually explicit cues in [porn addicts] in a network similar to that implicated in drug-cue-reactivity studies and provide support for incentive Cambridge University logomotivation theories of addiction underlying the aberrant response to sexual cues in [porn addicts]."
Novelty, Conditioning and Attentional Bias to Sexual Rewards (2015) -
Compared to controls porn addicts preferred sexual novelty and conditioned cues associated porn. However, the brains of porn addicts habituated faster to sexual images. Since novelty preference wasn't pre-existing, porn addiction drives novelty-seeking in an attempt to overcome habituation and desensitization.
Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior (2015) -
This Korean fMRI study replicates other brain studies on porn users. Like the Cambridge University studies it found cue-induced brain activation patterns in sex addicts which mirrored the patterns of drug addicts. In line with several German studies it found alterations in the prefrontal cortex which match the changes observed in drug addicts. What's new is that the findings perfectly matched the prefrontal cortex patterns observed in drug addicts: Greater cue-reactivity to sexual images, yet inhibited response to other normal stimuli.
Sexual Desire, not Hypersexuality, is Related to Neurophysiological Responses Elicited by Sexual Images (2013) -
This EEG study was touted in the media as evidence against the existence of porn addiction. Not so. This SPAN Lab study, like #7 below, actually supports the existence of porn addiction. Why? The study reported higher EEG readings (P300) when subjects were exposed to porn photos. Studies consistently show that an elevated P300 occurs when addicts are exposed to cues (such as images) related to their addiction. However, due to methodological flaws the findings are uninterpretable: 1) subjects were heterogeneous (males, females, non-heterosexuals); 2) subjects were not screened for mental disorders or addictions; 3) study had no control group for comparison; 4) questionnaires were not validated for porn addiction. In line with the Cambridge studies, this EEG study reported greater cue-reactivity to porn correlated with less desire for partnered sex. Neither finding matched the headlines. Three peer-reviewed papers expose the truth: 1, 2, 3.
Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (2015) -
Another SPAN Lab EEG study comparing the 2013 subjects from the above study to an actual control group (yet suffered from the same methodological flaws named above). The results: compared to controls porn addicts had less response to one-second exposure to photos of vanilla porn. The lead author, Nicole Prause, claims these results debunk porn addiction. However, these findings align perfectly with K?hn & Gallinat (2014), which found that more porn use correlated with less brain activation in response to pictures of vanilla porn. In other words, "porn addicts" were desensitized and needed greater stimulation than non-addicts. Three peer-reviewed papers agree with YBOP: 1, 2, 3. Read more.
HPA axis dysregulation in men with hypersexual disorder (2015) -
The Hypothalamus-Pituitary-Adrenal (HPA) axis is the central player in our stress response. Addictions alter the brain's stress circuits leading to a dysfunctional HPA axis. This study on sex addicts (hypersexuals) found altered stress responses that mirror drug addiction.
Increased sensitivity to erotic reward cues in subjects with compulsive sexual behaviors (2015) - (In the press)
This upcoming fMRI study compared reward center activity of controls to compulsive porn users. Compared to controls compulsive porn users had far greater reward center activity and attentional bias when exposed to sexual cues. Both findings align with the two Cambridge studies (above), and the accepted model of addiction - incentive sensitization.
Ventral striatum activity when watching preferred pornographic pictures is correlated with symptoms of Internet pornography addiction (2016)
Finding #1: Reward center activity (ventral striatum) was higher for preferred pornographic pictures. Finding #2: Ventral striatum reactivity correlated with the internet sex addiction score. Both findings indicate sensitization and align with the addiction model. The authors state that the "Neural basis of Internet pornography addiction is comparable to other addictions."
Neurobiology of Compulsive Sexual Behavior: Emerging Science (2016) -
Excerpt: "Given some similarities between CSB and drug addictions, interventions effective for addictions may hold promise for CSB, thus providing insight into future research directions to investigate this possibility directly."
Should compulsive sexual behavior be considered an addiction? (2016) -
Excerpt: "Overlapping features exist between CSB and substance use disorders. Common neurotransmitter systems may contribute to CSB and substance use disorders, and recent neuroimaging studies highlight similarities relating to craving and attentional biases. Similar pharmacological and psychotherapeutic treatments may be applicable to CSB and substance addictions, although considerable gaps in knowledge currently exist."
The above studies are all the "brain studies" published (or in the press) on internet porn users.
Together these brain studies found:
Neuro-Psychological Studies on Porn Users (with excerpts):
Watching Pornographic Pictures on the Internet: Role of Sexual Arousal Ratings and Psychological-Psychiatric Symptoms for Using Internet Sex Sites Excessively (2011) -
"We see some parallels between cognitive and brain mechanisms potentially contributing to the maintenance of excessive cybersex and those described for individuals with substance dependence"
Pornographic picture processing interferes with working memory performance (2013) -
"Results revealed worse WM performance in the pornographic picture condition of the 4-back task compared with the three remaining picture conditions. Findings are discussed with respect to Internet addiction because WM interference by addiction-related cues is well known from substance dependencies."
Sexual Picture Processing Interferes with Decision-Making Under Ambiguity (2013) -
"This study emphasized that sexual arousal interfered with decision-making, which may explain why some individuals experience negative consequences in the context of cybersex use."
Cybersex addiction: Experienced sexual arousal when watching pornography and not real-life sexual contacts makes the difference (2013) -
"The results support the gratification hypothesis, which assumes reinforcement, learning mechanisms, and craving to be relevant processes in the development and maintenance of cybersex addiction. Poor or unsatisfying sexual real life contacts cannot sufficiently explain cybersex addiction."
Cybersex addiction in heterosexual female users of internet pornography can be explained by gratification hypothesis (2014) -
"Results indicated that Internet porn users rated pornographic pictures as more arousing and reported greater craving due to pornographic picture presentation compared with non-users. Moreover, craving, sexual arousal rating of pictures, sensitivity to sexual excitation, problematic sexual behavior, and severity of psychological symptoms predicted tendencies toward cybersex addiction in porn users. Being in a relationship, number of sexual contacts, satisfaction with sexual contacts, and use of interactive cybersex were not associated with cybersex addiction."
Empirical Evidence and Theoretical Considerations on Factors Contributing to Cybersex Addiction From a Cognitive Behavioral View (2014) -
Previous work suggests that some individuals might be vulnerable to CA, while positive reinforcement and cue-reactivity are considered to be core mechanisms of CA development. In this study, 155 heterosexual males rated 100 pornographic pictures and indicated their increase of sexual arousal. Moreover, tendencies towards CA, sensitivity to sexual excitation, and dysfunctional use of sex in general were assessed. The results of the study show that there are factors of vulnerability to CA and provide evidence for the role of sexual gratification and dysfunctional coping in the development of CA.
Prefrontal control and internet addiction: a theoretical model and review of neuropsychological and neuroimaging findings (2015) -
"The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. Moreover, the results of the current study are comparable to findings from substance dependency research and emphasize analogies between cybersex addiction and substance dependencies or other behavioral addictions."
Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures. (2015) -
Recent studies show similarities between cybersex addiction and substance dependencies and argue to classify cybersex addiction as a behavioral addiction. In substance dependency, implicit associations are known to play a crucial role. Results show positive relationships between implicit associations of pornographic pictures with positive emotions and tendencies towards cybersex addiction, problematic sexual behavior, sensitivity towards sexual excitation as well as subjective craving.
Symptoms of cybersex addiction can be linked to both approaching and avoiding pornographic stimuli: results from an analog sample of regular cybersex users (2015) -
"Analogous to substance dependencies, results suggest that both approach and avoidance tendencies might play a role in cybersex addiction."
Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction (2015) -
The results of the current study point towards a role of executive control functions, i.e. functions mediated by the prefrontal cortex, for the development and maintenance of problematic cybersex use (as suggested by Brand et al., 2014). Particularly a reduced ability to monitor consumption and to switch between pornographic material and other contents in a goal adequate manner may be one mechanism in the development and maintenance of cybersex addiction.
Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting (2015) -
Study 1: Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2: Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards.
Sexual Excitability and Dysfunctional Coping Determine Cybersex Addiction in Homosexual Males (2015) -
Results showed strong correlations between CA symptoms and indicators of sexual arousal and sexual excitability, coping by sexual behaviors, and psychological symptoms. CA was not associated with offline sexual behaviors and weekly cybersex use time. Coping by sexual behaviors partially mediated the relationship between sexual excitability and CA. The results are comparable with those reported for heterosexual males and females in previous studies and are discussed against the background of theoretical assumptions of CA, which highlight the role of positive and negative reinforcement due to cybersex use.
Below are the studies:
Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) -
A German fMRI study which found 3 significant addiction-related brain changes correlating with the amount of porn consumed. It also found that more porn use correlated with less reward circuit activation while viewing sexual photos. Researchers stated their findings indicated desensitization, and possibly tolerance, the need for greater stimulation.
Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours (2014) -
The first in a series of Cambridge University studies found the same brain activity as seen in drug addicts and alcoholics. It also found that porn addicts fit the accepted addiction model of wanting "it" more, but not liking "it" more. The researchers also reported that 60% of subjects (average age: 25) had difficulty achieving erections/arousal with real partners, yet could achieve erections with porn.
Enhanced Attentional Bias towards Sexually Explicit Cues in Individuals with and without Compulsive Sexual Behaviours (2014) -
The second Cambridge University study. An excerpt: "Our findings of enhanced attentional bias... suggest possible overlaps with enhanced attentional bias observed in studies of drug cues in disorders of addictions. These findings converge with recent findings of neural reactivity to sexually explicit cues in [porn addicts] in a network similar to that implicated in drug-cue-reactivity studies and provide support for incentive Cambridge University logomotivation theories of addiction underlying the aberrant response to sexual cues in [porn addicts]."
Novelty, Conditioning and Attentional Bias to Sexual Rewards (2015) -
Compared to controls porn addicts preferred sexual novelty and conditioned cues associated porn. However, the brains of porn addicts habituated faster to sexual images. Since novelty preference wasn't pre-existing, porn addiction drives novelty-seeking in an attempt to overcome habituation and desensitization.
Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior (2015) -
This Korean fMRI study replicates other brain studies on porn users. Like the Cambridge University studies it found cue-induced brain activation patterns in sex addicts which mirrored the patterns of drug addicts. In line with several German studies it found alterations in the prefrontal cortex which match the changes observed in drug addicts. What's new is that the findings perfectly matched the prefrontal cortex patterns observed in drug addicts: Greater cue-reactivity to sexual images, yet inhibited response to other normal stimuli.
Sexual Desire, not Hypersexuality, is Related to Neurophysiological Responses Elicited by Sexual Images (2013) -
This EEG study was touted in the media as evidence against the existence of porn addiction. Not so. This SPAN Lab study, like #7 below, actually supports the existence of porn addiction. Why? The study reported higher EEG readings (P300) when subjects were exposed to porn photos. Studies consistently show that an elevated P300 occurs when addicts are exposed to cues (such as images) related to their addiction. However, due to methodological flaws the findings are uninterpretable: 1) subjects were heterogeneous (males, females, non-heterosexuals); 2) subjects were not screened for mental disorders or addictions; 3) study had no control group for comparison; 4) questionnaires were not validated for porn addiction. In line with the Cambridge studies, this EEG study reported greater cue-reactivity to porn correlated with less desire for partnered sex. Neither finding matched the headlines. Three peer-reviewed papers expose the truth: 1, 2, 3.
Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (2015) -
Another SPAN Lab EEG study comparing the 2013 subjects from the above study to an actual control group (yet suffered from the same methodological flaws named above). The results: compared to controls porn addicts had less response to one-second exposure to photos of vanilla porn. The lead author, Nicole Prause, claims these results debunk porn addiction. However, these findings align perfectly with K?hn & Gallinat (2014), which found that more porn use correlated with less brain activation in response to pictures of vanilla porn. In other words, "porn addicts" were desensitized and needed greater stimulation than non-addicts. Three peer-reviewed papers agree with YBOP: 1, 2, 3. Read more.
HPA axis dysregulation in men with hypersexual disorder (2015) -
The Hypothalamus-Pituitary-Adrenal (HPA) axis is the central player in our stress response. Addictions alter the brain's stress circuits leading to a dysfunctional HPA axis. This study on sex addicts (hypersexuals) found altered stress responses that mirror drug addiction.
Increased sensitivity to erotic reward cues in subjects with compulsive sexual behaviors (2015) - (In the press)
This upcoming fMRI study compared reward center activity of controls to compulsive porn users. Compared to controls compulsive porn users had far greater reward center activity and attentional bias when exposed to sexual cues. Both findings align with the two Cambridge studies (above), and the accepted model of addiction - incentive sensitization.
Ventral striatum activity when watching preferred pornographic pictures is correlated with symptoms of Internet pornography addiction (2016)
Finding #1: Reward center activity (ventral striatum) was higher for preferred pornographic pictures. Finding #2: Ventral striatum reactivity correlated with the internet sex addiction score. Both findings indicate sensitization and align with the addiction model. The authors state that the "Neural basis of Internet pornography addiction is comparable to other addictions."
Neurobiology of Compulsive Sexual Behavior: Emerging Science (2016) -
Excerpt: "Given some similarities between CSB and drug addictions, interventions effective for addictions may hold promise for CSB, thus providing insight into future research directions to investigate this possibility directly."
Should compulsive sexual behavior be considered an addiction? (2016) -
Excerpt: "Overlapping features exist between CSB and substance use disorders. Common neurotransmitter systems may contribute to CSB and substance use disorders, and recent neuroimaging studies highlight similarities relating to craving and attentional biases. Similar pharmacological and psychotherapeutic treatments may be applicable to CSB and substance addictions, although considerable gaps in knowledge currently exist."
The above studies are all the "brain studies" published (or in the press) on internet porn users.
Together these brain studies found:
- The 3 major addiction-related brain changes: sensitization, desensitization, and hypofrontality.
- More porn use correlated with less grey matter in the reward circuit (dorsal striatum).
- More porn use correlated with less reward circuit activation when briefly viewing sexual images.
- More porn use correlated with disrupted neural connections between the reward circuit and prefrontal cortex.
- Addicts had greater prefrontal activity to sexual cues, but less brain activity to normal stimuli (matches drug addiction).
- 60% of compulsive porn addicted subjects in one study experienced ED or low libido with partners, but not with porn: all stated that internet porn use caused their ED/low libido.
- Enhanced attentional bias comparable to drug users. Indicates sensitization (a product of DeltaFosb).
- Greater wanting & craving for porn, but not greater liking. This aligns with the accepted model of addiction - incentive sensitization.
- The younger the porn users the greater the cue-induced reactivity in the reward center.
- Higher EEG (P300) readings when porn users were exposed to porn cues (which occurs in other addictions).
- Less desire for sex with a person correlating with greater cue-reactivity to porn images.
- More porn use correlated with lower LPP amplitude when briefly viewing sexual photos: indicates habituation or desensitization.
- Dysfunctional HPA axis which reflects altered brain stress circuits, which occurs in drug addictions.
Neuro-Psychological Studies on Porn Users (with excerpts):
Watching Pornographic Pictures on the Internet: Role of Sexual Arousal Ratings and Psychological-Psychiatric Symptoms for Using Internet Sex Sites Excessively (2011) -
"We see some parallels between cognitive and brain mechanisms potentially contributing to the maintenance of excessive cybersex and those described for individuals with substance dependence"
Pornographic picture processing interferes with working memory performance (2013) -
"Results revealed worse WM performance in the pornographic picture condition of the 4-back task compared with the three remaining picture conditions. Findings are discussed with respect to Internet addiction because WM interference by addiction-related cues is well known from substance dependencies."
Sexual Picture Processing Interferes with Decision-Making Under Ambiguity (2013) -
"This study emphasized that sexual arousal interfered with decision-making, which may explain why some individuals experience negative consequences in the context of cybersex use."
Cybersex addiction: Experienced sexual arousal when watching pornography and not real-life sexual contacts makes the difference (2013) -
"The results support the gratification hypothesis, which assumes reinforcement, learning mechanisms, and craving to be relevant processes in the development and maintenance of cybersex addiction. Poor or unsatisfying sexual real life contacts cannot sufficiently explain cybersex addiction."
Cybersex addiction in heterosexual female users of internet pornography can be explained by gratification hypothesis (2014) -
"Results indicated that Internet porn users rated pornographic pictures as more arousing and reported greater craving due to pornographic picture presentation compared with non-users. Moreover, craving, sexual arousal rating of pictures, sensitivity to sexual excitation, problematic sexual behavior, and severity of psychological symptoms predicted tendencies toward cybersex addiction in porn users. Being in a relationship, number of sexual contacts, satisfaction with sexual contacts, and use of interactive cybersex were not associated with cybersex addiction."
Empirical Evidence and Theoretical Considerations on Factors Contributing to Cybersex Addiction From a Cognitive Behavioral View (2014) -
Previous work suggests that some individuals might be vulnerable to CA, while positive reinforcement and cue-reactivity are considered to be core mechanisms of CA development. In this study, 155 heterosexual males rated 100 pornographic pictures and indicated their increase of sexual arousal. Moreover, tendencies towards CA, sensitivity to sexual excitation, and dysfunctional use of sex in general were assessed. The results of the study show that there are factors of vulnerability to CA and provide evidence for the role of sexual gratification and dysfunctional coping in the development of CA.
Prefrontal control and internet addiction: a theoretical model and review of neuropsychological and neuroimaging findings (2015) -
"The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. Moreover, the results of the current study are comparable to findings from substance dependency research and emphasize analogies between cybersex addiction and substance dependencies or other behavioral addictions."
Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures. (2015) -
Recent studies show similarities between cybersex addiction and substance dependencies and argue to classify cybersex addiction as a behavioral addiction. In substance dependency, implicit associations are known to play a crucial role. Results show positive relationships between implicit associations of pornographic pictures with positive emotions and tendencies towards cybersex addiction, problematic sexual behavior, sensitivity towards sexual excitation as well as subjective craving.
Symptoms of cybersex addiction can be linked to both approaching and avoiding pornographic stimuli: results from an analog sample of regular cybersex users (2015) -
"Analogous to substance dependencies, results suggest that both approach and avoidance tendencies might play a role in cybersex addiction."
Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction (2015) -
The results of the current study point towards a role of executive control functions, i.e. functions mediated by the prefrontal cortex, for the development and maintenance of problematic cybersex use (as suggested by Brand et al., 2014). Particularly a reduced ability to monitor consumption and to switch between pornographic material and other contents in a goal adequate manner may be one mechanism in the development and maintenance of cybersex addiction.
Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting (2015) -
Study 1: Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2: Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards.
Sexual Excitability and Dysfunctional Coping Determine Cybersex Addiction in Homosexual Males (2015) -
Results showed strong correlations between CA symptoms and indicators of sexual arousal and sexual excitability, coping by sexual behaviors, and psychological symptoms. CA was not associated with offline sexual behaviors and weekly cybersex use time. Coping by sexual behaviors partially mediated the relationship between sexual excitability and CA. The results are comparable with those reported for heterosexual males and females in previous studies and are discussed against the background of theoretical assumptions of CA, which highlight the role of positive and negative reinforcement due to cybersex use.
