Table 3.

Details of experimental studies included in the review (N = 7).

Study	Sample	Method	Assessment	Results
Laier et al., 2013 (Journal of Behavioral Addictions)	171 German heterosexual men who used cybersex at least once recruited by advertisements in public or on campus of the University. Mean Age = 24.56 years. (Study 1)50 heterosexual males who perceived problems regarding controlling their cybersex use with 25 Problematic Cybersex Users (PCU) (sIATsex score > 30, Mean age = 23.96 y.) and 25 Health Cybersex Users (HCU) (Mean age = 22.88 y.). They were recruited by advertisements in local newspapers and by announcements in the public and on campus of University (Study 2) No data on cultural context.	100 pornographic cues were presented to participants. Indicators of sexual arousal and need to masturbate were evaluated. The severity of cybersex addiction was assessed with a short version of the Internet Addiction Test (sIAT) modified for cybersex. Prior to (t1) and directly after (t2) the experimental paradigm, participants indicated their sexual arousal from 0 to 100 as well as their need to masturbate from 0 to 100. As indicators of craving, the sexual arousal and the need to masturbate at t1 were subtracted from the same collected data at t2.	sIATsex (Short Internet Addiction Test-Sex) Score Sexual arousal, need to masturbate, viewing time, craving from sexual arousal and the need to masturbate before and after exposure	Sexual arousal and craving data of pornographic cues on the Internet were positively correlated with the sIATsex score and therefore with the presence and severity of sexual addiction. (Study 1)Significant difference in the intensity of craving and sexual arousal between the two groups with a higher intensity found in problem users. (Study 2) . The problematic cybersex users group showed higher subjective sexual arousal and a greater need to masturbate when being confronted with pornographic pictures.
Kraus et al., 2014 (Archives of Sexual Behavior)	221 American male students pornography users were recruited. Mean age = 21.8 y.; Sexual orientation: heterosexual = 81% (n = 179), gay/bisexual = 16% (n = 35,36), uncertain = 2% (n = 4,42) Ethnic data: 87% white/European, 4% black/African American, 9% other (Asian, latino, bi-racial) (Study 2) 67 male psychology students and pornography users were recruited by email. Mean age = 20.2 y. Sexual orientation: Heterosexual = 84% (n = 56), gay/bisexual = 11% (n = 7), uncertain = 2%. Ethnic data: 91% white/European, 5% black/African American, 2% other (Asian, latino, bi-racial) (Study 3)	Exposure to pornography and to neutral images. Before exposure to sexual cues, participants were asked to imagine himself sitting in front of his computer, alone in his room, while experiencing a strong urge to watch his favorite type of pornography. Association of craving scores with weekly pornography use level, signal exposure, and sexual compulsivity (SCS) were assessed (Study 2).Test-retest reliability assessment at one week (Study 3) .	Post-cue exposure reports of craving with PCQ (Pornography Craving Questionnaire)Sexual compulsivity by the SCS (Sexual Compulsivity Scale) .	There was a main effect of typical weekly pornography use on total PCQ scores. Specifically, participants who used pornography 6 times a week reported higher craving than did individuals who used pornography 3-to-5 times per week who in turn reported higher craving than those who used pornography only 0-to-2 times per week. PCQ scores were significantly positively correlated with sexual compulsivity (SCS score). Weekly pornography use and PCQ scores were significant predictors of pornography use in the following week
Laier et al., 2014 (Cyberpsychology, Behavior, and social networking)	102 German adult heterosexual female participants (Mean age = 21.83 y.) were recruited by advertisements in public and at the University of Duisburg-Essen (Germany) in 2012Sample was separated into 2 groups: females watching pornography (hardcore pictures or videos) on the Internet on a regular basis (IPU) (n = 51) and females not watching hardcore pornography on the Internet (NIPU) (n = 51). No data on cultural context.	Comparison of females IPU and NIPU on the severity of cybersex addiction (sIATsex), as well as propensity for sexual excitation, general problematic sexual behavior (HBI), and severity of psychological symptoms (in the last 7 days: BSI with Global severity index (GSI)). Additionally, an experimental paradigm, including a subjective arousal rating of 100 pornographic pictures, as well as indicators of craving, was conducted.	sIATsex (Short Internet Addiction Test-Sex), HBI (Hypersexual Behavior Inventory), BSI (GSI) overall scoreMeasurement before (t1) and after (t2) exposure: -Sexual arousal -Need to masturbate -Viewing time Calculation of craving from sexual arousal and the need to masturbate by subtracting t2 from t1.	Average sexual arousal scores at pornographic images were higher for the IPU versus NIPU group with more intense craving for the IPU group.In the IPU group, overall sIATsex score correlated with sexual arousal and craving,
Snagowski et al., 2015 (Addictive Behaviors)	A total of 128 German heterosexual males (Mean age = 23.88 years), regular users, participated in the study. Individuals were recruited through local advertisements at the University of Duisburg-Essen (Germany) and online platforms. Participants reported that their age of first cybersex use was 15.51 years. No data about cultural context.	Participants completed a modified Implicit Association Test (IAT) with pornographic images. Viewing pornographic images made it possible to measure several data including craving. To assess tendencies towards cybersex addiction, sIAT-sex was used. Additionally, to assess sensitivity towards sexual excitation, a short form of the Sexual Excitation Scale was used (SES) and general problematic sexual behavior was measured by the Hypersexual Behavioral Inventory (HBI).	Sexual arousal and need to masturbate were assessed before (t1) and after (t2) sexual cue exposure on a scale ranging from 0 to 100.By subtracting t1 from t2 measurement, Δ-scores of sexual arousals and need to masturbate were computed and operationalized as subjective measures of craving, Tendencies towards cybersex addiction was assessed with the sIAT-sex Problematic Sexual Behavior was assessed with the Hypersexual Behavioral Inventory (HBI) Sensitivity to sexual arousal was assessed with the Sexual Excitation Scale (SES)	Higher subjective craving was associated with tendencies towards cybersex addiction The craving Δ sexual arousal explained 19.1 % variance of the sIAT-sex craving/social problems.
Snagowski et al., 2016 (Sexual addiction & compulsivity)	86 German heterosexual men (Mean age = 23.70 years), regular cybersex users were recruited through local advertisements at University Duisburg-Essen and online platforms. The mean age of first cybersex use was 15.73 years. No data on cultural context.	The current subjective sexual arousal and need to masturbate were assessed before and after exposure to 50 pornographic images. Then, participants completed the S-PIT modified with pornographic pictures (S-PITsex). S-PIT is based on Pavlovian packaging related or not to substances.	Assessment of sexual arousal and the need to masturbate before (t1) and after (t2) exposure to pornographic images. Craving to pornography was measured by subtracting t1 from t2.The S-PIT adapted to pornographic images assesses whether sexual arousal (as a rewarding result) could be conditioned to neutral stimuli and whether these conditioned stimuli could induce craving Tendencies towards cybersex addiction were measured with sIATsex questionnaire.	Cybersex addiction was associated with conditioning processes regarding pornographic images.Participants who reported both strong craving to pornography as well as high conditioning effects were at higher risk of being addicted to cybersex (sIATsex score) .
Antons et al., 2018 (Addictive Behaviors)	50 German heterosexual male students (Mean age = 23.30) who use heterosexual pornography were recruited through local advertisements at the University and online advertisement in the university's internal networks. No data on cultural context.	Each participant was exposed to neutral and pornographic images during a stop-signal task. Craving was assessed with a scale ranging from 0 to 100 at 3 points in time: before exposure, after neutral image and after pornographic image.	Craving was assessed with a scale ranging from 0 to 100Severity of problematic cybersex was assessed with the sIATsex (Short Internet Addiction Test-Sex) overall score.	Positive association was found between sIATsex severity score and craving. Low craving level after exposure to a pornographic image, was associated with low severity of symptoms, while high craving and impulsivity scores were associated with higher sIATsex severity scores.
Pekal et al., 2018 (Journal of Behavioral Addictions)	174 German participants (n = 87 females, mean age = 23.59, range: 18–52 years) recruited trough offline and online advertisements at the University Duisburg-Essen. No data on cultural context.	Sexual arousal and craving were induced by exposure to 100 pornographic pictures.Before (t1) and after (t2) the picture presentation, the participants had to indicate their current sexual arousal and their need to masturbate on a scale ranging from 1 to 100. The increase of sexual arousal(arousal Δ) and of the need to masturbate(craving masturbation Δ) were assumed as the indicators for cue-reactivity and craving responses and were calculatedby subtracting t2 from t1. Furthermore, the role of attentional bias in the development of internet sexual addiction was investigated.	Sexual arousal and need to masturbate were assessed with a scale ranging from 1 to 100.Trends in problematic IP use were measured using the sIATsex (Short Internet Addiction Test-Sex) test. Attentional bias was assessed with the Visual Probe Task.	Individuals with a high attentional bias towards sexual stimuli reported greater symptoms of problematic internet pornography use (craving). Significant positive correlations were found between: - the overall sIATsex score, the sIATsex-Loss of Control and sIATsex-craving subscales, as well as the increased need to masturbate, and sexual arousal. - the responsiveness to stimuli/craving and symptoms of problematic use of pornography on the Internet.