Prefrontal Control and Internet Addiction: A Theoretical Model and Review of Neuropsychological and Neuroimaging Findings

“…see patients suffering from severe negative consequences due to an overuse of the Internet in general or certain Internet applications, the terminology used for this phenomenon and its classification are still under debate (Young, 1998b, 1999; Charlton and Danforth, 2007; Starcevic, 2013).”

“…(via the thalamus) and the limbic loop connecting limbic structures, such as the amygdala, and structures that are linked to motivational aspects of behavior, such as the nucleus accumbens, with the orbitofrontal and ventromedial part of the prefrontal brain area (Alexander and Crutcher, 1990).”

“They are consistent with neurobiological and psychological models of addition (Robinson and Berridge,2003; Everitt and Robbins,2006) and with neuropsychological and neuroimaging findings in substance dependency and other forms of behavioral additions (Grant et al., 2006; van Holst et al., 2010).”

“All authors are accountable for all aspects of the work.”

“…parallels between Internet addiction and other so-called behavioral addictions (e.g., Grant et al., 2013) and substance dependency (see also Griffiths, 2005; Meerkerk et al., 2009), which we will summarize in Sections “Neuropsychological Correlates of Internet Addiction” and “Neuroimaging…”

“Davis (2001) introduced a theoretical cognitive–behavioral model on pathological or problematic Internet use and differentiates between a generalized pathological Internet use, which we call generalized Internet addiction (GIA), and a specific pathological Internet use, for which we use the term…”

“This has already been shown, for example for cybersex addiction (Brand et al., 2011; Laier et al., 2013a) and is most likely also a mechanism for online gaming (e.g., Tychsen et al., 2006; Yee, 2006).”

“This is most likely the consequence of changes in the dopaminergic reward system by frontal-guided changes of glutaminergic innervation of the nucleus accumbens and related brain areas (Kalivas and Volkow, 2005).”

“In the first stages of drug-dependency development, frontal brain areas are particularly involved in the decision to consume a certain drug, motivated by its reinforcing effects (Goldstein and Volkow, 2002).”

“The excessive Internet users in the study by Sun et al. (2009) had problems in performing the Iowa Gambling Task, indicating decision-making deficits, which had frequently been linked to addictive behaviors (Bechara, 2005).”

“These functions are strongly linked to parts of the prefrontal cortex, in particular the dorsolateral prefrontal cortex (e.g., Alvarez and Emory, 2006; Bari and Robbins, 2013; Yuan and Raz, 2014).”

“These functions are strongly linked to parts of the prefrontal cortex, in particular the dorsolateral prefrontal cortex (e.g., Alvarez and Emory, 2006; Bari and Robbins, 2013; Yuan and Raz, 2014).”

“The excessive Internet users in the study by Sun et al. (2009) had problems in performing the Iowa Gambling Task, indicating decision-making deficits, which had frequently been linked to addictive behaviors (Bechara, 2005).”

“This assumption fits well with recent models on the development of addictive behavior in general, as suggested by Robinson and Berridge (2008), as already mentioned.”

“Executive functions are control systems allowing us to regulate our behavior that is planned, goal oriented, flexible, and effective (Shallice and Burgess, 1996; Jurado and Rosselli, 2007; Anderson et al., 2008).”

“…involved in cognitive control, in particular the dorsolateral prefrontal cortex (see Figure 2) receives dopaminergic projections from the basal ganglia and the nucleus accumbens, functional changes in these structures can also reduce the integrity of executive control (Cools and D’Esposito, 2011).”

“…so strong that they experience cue-reactivity and craving, as it is well-known from substance dependency (e.g., Grant et al., 1996; Anton, 1999; Childress et al., 1999; Tiffany and Conklin, 2000; Bonson et al., 2002; Brody et al., 2002, 2007; Franken, 2003; Dom et al., 2005; Heinz et al.,…”

“…satisfy certain desires increases the likelihood that these Internet applications are used frequently, as assumed in addictive behavior in general (Robinson and Berridge, 2000, 2003; Everitt and Robbins, 2006) and that the individual can develop a loss of control over his/her use of such…”

“Results illustrate similarities between Internet addiction and other addiction conditions with respect to underlying mechanisms of development, in particular conditioning processes (Robinson and Berridge, 2001, 2003; Thalemann et al., 2007).”

“…and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related addictive behavior (Brenner, 1997), Internet-related problems (Widyanto et al., 2008), problematic Internet use (Caplan, 2002), and pathological Internet use (Davis, 2001).”

“…applications (SIA), we argue – consistent with previous research and in accordance with the model by Davis (2001) – that psychopathological symptoms are particularly involved (Brand et al., 2011; Kuss and Griffith, 2011; Pawlikowski and Brand, 2011; Laier et al., 2013a; Pawlikowski et al., 2014).”

“The first scientific description of a young man who developed severe psychosocial problems due to his excessive Internet use was done by Young (1996).”

“One example for such a specific predisposition is a high sexual excitation (Cooper et al., 2000a,b; Bancroft and Vukadinovic, 2004; Salisbury, 2008; Kafka, 2010), which makes it more likely that an individual uses Internet pornography, because he/she anticipates sexual arousal and gratification (Meerkerk et al.”

“These persons experience a loss of control over their Internet use and report social problems as well as school and/or work difficulties (Young, 1998a; Beard and Wolf, 2001).”

“…between Internet addiction and other so-called behavioral addictions (e.g., Grant et al., 2013) and substance dependency (see also Griffiths, 2005; Meerkerk et al., 2009), which we will summarize in Sections “Neuropsychological Correlates of Internet Addiction” and “Neuroimaging Correlates of…”

“, 2005) and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing factors for deve…”

“…see patients suffering from severe negative consequences due to an overuse of the Internet in general or certain Internet applications, the terminology used for this phenomenon and its classification are still under debate (Young, 1998b, 1999; Charlton and Danforth, 2007; Starcevic, 2013).”

“…to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known from substance dependency (e.g., Grant et al., 1996; Anton, 1999; Childress et al., 1999; Tiffany and Conklin, 2000; Bonson et al., 2002; Brody et al., 2002, 2007; Franken, 2003; Dom…”

“It was followed by a growing number of other single- and multiple-case studies (e.g., Griffiths, 2000).”

“They used the Iowa Gambling Task (Bechara et al., 2000), which had been used in many studies with different patient populations with neurological and psychiatric diseases including substance dependency and behavioral addictions before (cf. Dunn et al., 2006).”

“Today, a relatively large literature exists on the phenomenology, the epidemiology for different countries, and co-morbidity of a problematic or pathological Internet use (see recent review by Spada, 2014).”

“the behavior to use the Internet again and again, although a person explicitly knows that he/she will experience negative consequences in the long run? Do they have a myopia for the future or is the reaction to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known…”

“…terms used in the scientific literature when referring to an overuse of the Internet, such as Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related…”

“In addition, social cognitions, such as perceived social isolation and a lack of social support offline are supposed to be related to GIA (Morahan-Martin and Schumacher, 2003; Caplan, 2005).”

“We also assume that psychopathological symptoms, in particular depression and social anxiety (e.g.,Whang et al., 2003; Yang et al., 2005) and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and…”

“All authors are accountable for all aspects of the work.”

“…scientific literature when referring to an overuse of the Internet, such as Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related addictive behavior…”

“, the orbitofrontal cortex) learn to habitually react on drug cues with craving and the dorsolateral prefrontal cortex, which is linked to higher-order cognitive functions, loses its regulatory influences (Bechara, 2005; Goldstein et al., 2009).”

“Executive functions are control systems allowing us to regulate our behavior that is planned, goal oriented, flexible, and effective (Shallice and Burgess, 1996; Jurado and Rosselli, 2007; Anderson et al., 2008).”

“…and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing…”

“These functions are strongly linked to parts of the prefrontal cortex, in particular the dorsolateral prefrontal cortex (e.g., Alvarez and Emory, 2006; Bari and Robbins, 2013; Yuan and Raz, 2014).”

“the behavior to use the Internet again and again, although a person explicitly knows that he/she will experience negative consequences in the long run? Do they have a myopia for the future or is the reaction to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known…”

“In addition, social cognitions, such as perceived social isolation and a lack of social support offline are supposed to be related to GIA (Morahan-Martin and Schumacher, 2003; Caplan, 2005).”

“We also hypothesize that specific person’s predispositions increase the probability that an individual receives gratification from the use of certain applications and overuses these applications again.”

“The results were very similar to those reported in substance-dependent individuals (Schacht et al., 2013).”

“” This criterion is also a factor frequently found when analyzing the factorial structure of questionnaires used to assess Internet addiction (Chang and Law, 2008; Korkeila et al., 2010; Widyanto et al., 2011; Lortie and Guitton, 2013; Pawlikowski et al., 2013).”

“the behavior to use the Internet again and again, although a person explicitly knows that he/she will experience negative consequences in the long run? Do they have a myopia for the future or is the reaction to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known…”

“Furthermore, performing the Dice Task well is linked to prefrontal integrity (Labudda et al., 2008) and executive functions Frontiers in Human Neuroscience www.frontiersin.org May 2014 | Volume 8 | Article 375 | 5 (e.g., Brand et al., 2006; Brand et al., 2008a, 2009).”

“One example for such a specific predisposition is a high sexual excitation (Cooper et al., 2000a,b; Bancroft and Vukadinovic, 2004; Salisbury, 2008; Kafka, 2010), which makes it more likely that an individual uses Internet pornography, because he/she anticipates sexual arousal and gratification (Meerkerk et al.”

“It is connected to several basal ganglia, in particular to the nucleus caudatus and putamen via the so-called fronto-striatal loops.”

“(Brand et al., 2008b), and pathological gambling (Brand et al., 2005b).”

“These approaches have already been transferred to behavioral addictions, such as pathological gambling (e.g., Goudriaan et al., 2004; Brand et al., 2005b; Goudriaan et al., 2005, 2006; van Holst et al., 2010; Conversano et al., 2012) and compulsive buying (e.g., Black et al., 2012).”

“the behavior to use the Internet again and again, although a person explicitly knows that he/she will experience negative consequences in the long run? Do they have a myopia for the future or is the reaction to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known…”

“We now applied the same search and inclusion criteria as documented in the review by Kuss and Griffiths (2012) and identified 13 studies (excluding EEG studies) published in peer-reviewed journals from January 2013 to end of January 2014.”

“…experience cue-reactivity and craving, as it is well-known from substance dependency (e.g., Grant et al., 1996; Anton, 1999; Childress et al., 1999; Tiffany and Conklin, 2000; Bonson et al., 2002; Brody et al., 2002, 2007; Franken, 2003; Dom et al., 2005; Heinz et al., 2008; Field et al., 2009)?”

“…facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing factors for developing a GIA.”

“We argue, however, that also other applications can be used addictively (Young et al., 1999; Meerkerk et al., 2006).”

“Cognitive–behavioral therapy is the method of choice (Cash et al., 2012; Winkler et al., 2013), although the number of empirical studies on treatment outcome is still limited (Young, 2013), as it is the case for other behavioral addictions (Grant et al., 2013).”

“This has already been shown, for example for cybersex addiction (Brand et al., 2011; Laier et al., 2013a) and is most likely also a mechanism for online gaming (e.g., Tychsen et al., 2006; Yee, 2006).”

“They are consistent with neurobiological and psychological models of addition (Robinson and Berridge,2003; Everitt and Robbins,2006) and with neuropsychological and neuroimaging findings in substance dependency and other forms of behavioral additions (Grant et al., 2006; van Holst et al., 2010).”

“” This criterion is also a factor frequently found when analyzing the factorial structure of questionnaires used to assess Internet addiction (Chang and Law, 2008; Korkeila et al., 2010; Widyanto et al., 2011; Lortie and Guitton, 2013; Pawlikowski et al., 2013).”

“the behavior to use the Internet again and again, although a person explicitly knows that he/she will experience negative consequences in the long run? Do they have a myopia for the future or is the reaction to the Internet-related stimuli so strong that they experience cue-reactivity and craving, as it is well-known…”

“…in prefrontal brain areas related to cue-reactivity and gaming urges in excessive players have also been reported in other previous studies (e.g., Han et al., 2010b; Ko et al., 2013a; Lorenz et al., 2013) and comparisons between cue-reactivity on gaming stimuli and substance dependency (e.g.,…”

“…experience cue-reactivity and craving, as it is well-known from substance dependency (e.g., Grant et al., 1996; Anton, 1999; Childress et al., 1999; Tiffany and Conklin, 2000; Bonson et al., 2002; Brody et al., 2002, 2007; Franken, 2003; Dom et al., 2005; Heinz et al., 2008; Field et al., 2009)?”

“These approaches have already been transferred to behavioral addictions, such as pathological gambling (e.g., Goudriaan et al., 2004; Brand et al., 2005b; Goudriaan et al., 2005, 2006; van Holst et al., 2010; Conversano et al., 2012) and compulsive buying (e.g., Black et al., 2012).”

“These areas, but also the amygdala and the orbitofrontal cortex, are related to craving (Chase et al., 2011).”

“It is connected to several basal ganglia, in particular to the nucleus caudatus and putamen via the so-called fronto-striatal loops.”

“Reductions in gray matter density were also found in the left anterior and posterior cingulate cortex, as well as in the insula (Zhou et al., 2011) and in the orbitofrontal cortex (Hong et al., 2013a; Yuan et al., 2013).”

“This criterion is also a factor frequently found when analyzing the factorial structure of questionnaires used to assess Internet addiction (Chang and Law, 2008; Korkeila et al., 2010; Widyanto et al., 2011; Lortie and Guitton, 2013; Pawlikowski et al., 2013).”

“For example, Lin et al. (2012) found lower fractional anisotropy in large parts of the brain of individuals with Internet addiction including the orbitofrontal cortex.”

“They identified 18 studies, which used either functional magnetic resonance imaging (fMRI), positron emission tomography (PET), structural MRI or electroencephalography (EEG).”

“…and gaming urges in excessive players have also been reported in other previous studies (e.g., Han et al., 2010b; Ko et al., 2013a; Lorenz et al., 2013) and comparisons between cue-reactivity on gaming stimuli and substance dependency (e.g., tobacco) have been discussed (Ko et al., 2013b).”

“Regarding the development and maintenance of an addictive use of specific Internet applications (SIA), we argue – consistent with previous research and in accordance with the model by Davis (2001) – that psychopathological symptoms are particularly involved (Brand et al., 2011; Kuss and Griffith, 2011; Pawlikowski and…”

“We also assume that psychopathological symptoms, in particular depression and social anxiety (e.g.,Whang et al., 2003; Yang et al., 2005) and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al.”

“…experience cue-reactivity and craving, as it is well-known from substance dependency (e.g., Grant et al., 1996; Anton, 1999; Childress et al., 1999; Tiffany and Conklin, 2000; Bonson et al., 2002; Brody et al., 2002, 2007; Franken, 2003; Dom et al., 2005; Heinz et al., 2008; Field et al., 2009)?”

“…see patients suffering from severe negative consequences due to an overuse of the Internet in general or certain Internet applications, the terminology used for this phenomenon and its classification are still under debate (Young, 1998b, 1999; Charlton and Danforth, 2007; Starcevic, 2013).”

“…and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing…”

“This has already been shown, for example for cybersex addiction (Brand et al., 2011; Laier et al., 2013a) and is most likely also a mechanism for online gaming (e.g., Tychsen et al., 2006; Yee, 2006).”

“Results illustrate similarities between Internet addiction and other addiction conditions with respect to underlying mechanisms of development, in particular conditioning processes (Robinson and Berridge, 2001, 2003; Thalemann et al., 2007).”

“, 2005) and dysfunctional personality facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing factors for deve…”

“…Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related addictive behavior (Brenner, 1997), Internet-related problems (Widyanto et al., 2008),…”

“All authors are accountable for all aspects of the work.”

“This has already been shown, for example for cybersex addiction (Brand et al., 2011; Laier et al., 2013a) and is most likely also a mechanism for online gaming (e.”

“STRUCTURAL AND RESTING-STATE NEUROIMAGING IN INTERNET ADDICTION A study on both structural and functional neural correlates of Internet/computer gaming with a large sample (N = 154) adolescents reported higher gray matter volume in left ventral striatal region in frequent/excessive compared to infrequent players (Kühn…”

“…and gaming urges in excessive players have also been reported in other previous studies (e.g., Han et al., 2010b; Ko et al., 2013a; Lorenz et al., 2013) and comparisons between cue-reactivity on gaming stimuli and substance dependency (e.g., tobacco) have been discussed (Ko et al., 2013b).”

“They studied excessive World-of-Warcraft (WoW) players (all participants played at least 30 h a week) with fMRI using a picture paradigm, which is comparable with those previously used in alcohol addiction research (e.g., Braus et al., 2001; Grüsser et al., 2004).”

“The orbitofrontal cortex (OFC) and the ventromedial prefrontal cortex (vmPFC) are critically linked to reward anticipation, emotion processing, and decision making under ambiguity.”

“A comparable finding was reported by Sun et al. (2012), who also investigated excessive WoW players with a picture paradigm to induce craving.”

“Within CBT-IA model proposed by Young (2011), individual characteristics as well as specific cognitions have been hypothesized to be key elements, which should be addressed in the therapy.”

“(Brand et al., 2008b), and pathological gambling (Brand et al.”

“Problems in making good decisions, meaning that individuals with Internet addiction continue playing games even though they are confronted with negative consequences, might be related to their problems in everyday-life (see also discussion in Pawlikowski and Brand, 2011).”

“…Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related addictive behavior (Brenner, 1997), Internet-related problems (Widyanto et al., 2008),…”

“…in prefrontal brain areas related to cue-reactivity and gaming urges in excessive players have also been reported in other previous studies (e.g., Han et al., 2010b; Ko et al., 2013a; Lorenz et al., 2013) and comparisons between cue-reactivity on gaming stimuli and substance dependency (e.g.,…”

“One example for such a specific predisposition is a high sexual excitation (Cooper et al., 2000a,b; Bancroft and Vukadinovic, 2004; Salisbury, 2008; Kafka, 2010), which makes it more likely that an individual uses Internet pornography, because he/she anticipates sexual arousal and gratification…”

“Consistent with this, Han et al. (2011) found that the desire to play was positively related to activity in the right mediofrontal lobe and right parahippocampal gyrus even in healthy subjects, who were trained to play a certain video game for 10 days.”

“Gray matter reductions in the (right) orbitofrontal cortex in individuals with SIA for games, in addition also in the insula (bilaterally), and the right supplementary motor area were reported by Weng et al. (2013).”

“” This criterion is also a factor frequently found when analyzing the factorial structure of questionnaires used to assess Internet addiction (Chang and Law, 2008; Korkeila et al., 2010; Widyanto et al., 2011; Lortie and Guitton, 2013; Pawlikowski et al., 2013).”

“With respect to the ability to inhibit responses to certain stimuli, the individuals investigated by Sun et al. (2009) performed normally on a Go/No-Go Task, which measures response inhibition functions.”

“All authors are accountable for all aspects of the work.”

“…to an overuse of the Internet, such as Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010), Internet-related addictive behavior (Brenner, 1997),…”

“(Brand et al., 2008b), and pathological gambling (Brand et al., 2005b).”

“The orbitofrontal cortex (OFC) and the ventromedial prefrontal cortex (vmPFC) are critically linked to reward anticipation, emotion processing, and decision making under ambiguity.”

“They should inspire incorporating neurobiological findings into treatment designs for Internet addiction, as it has been proposed for other forms of behavioral addictions (Potenza et al., 2013).”

“Furthermore, performing the Dice Task well is linked to prefrontal integrity (Labudda et al., 2008) and executive functions Frontiers in Human Neuroscience www.frontiersin.org May 2014 | Volume 8 | Article 375 | 5 (e.g., Brand et al., 2006; Brand et al., 2008a, 2009).”

“, 2006, 2009, 2010), Internet-related addictive behavior (Brenner, 1997), Internet-related problems (Widyanto et al., 2008), problematic Internet use (Caplan, 2002), and pathological Internet use (Davis, 2001).”

“…of different terms used in the scientific literature when referring to an overuse of the Internet, such as Internet addiction (Young, 1998b, 2004; Hansen, 2002; Chou et al., 2005; Widyanto and Griffiths, 2006; Young et al., 2011), compulsive Internet use (Meerkerk et al., 2006, 2009, 2010),…”

“, 2013), although the number of empirical studies on treatment outcome is still limited (Young, 2013), as it is the case for other behavioral addictions (Grant et al., 2013).”

“Furthermore, performing the Dice Task well is linked to prefrontal integrity (Labudda et al., 2008) and executive functions”

“This has already been shown, for example for cybersex addiction (Brand et al., 2011; Laier et al., 2013a) and is most likely also a mechanism for online gaming (e.g., Tychsen et al., 2006; Yee, 2006).”

“These kinds of conditioning processes are well-known for other forms of addiction and substance dependency (e.g., Robinson and Berridge, 2000, 2001; Everitt and Robbins, 2006; Robinson and Berridge, 2008; Loeber and Duka, 2009).”

“Also using fMRI, Dong et al. (2013b) investigated decisionmaking competence in individuals with Internet addiction (without specifying the type of Internet addiction).”

“…applications (SIA), we argue – consistent with previous research and in accordance with the model by Davis (2001) – that psychopathological symptoms are particularly involved (Brand et al., 2011; Kuss and Griffith, 2011; Pawlikowski and Brand, 2011; Laier et al., 2013a; Pawlikowski et al., 2014).”

“The WoW players had, compared to the control group, stronger activations within the nucleus accumbens, the orbitofrontal cortex, and the caudate while watching WoW pictures.”

“One may hypothesize that individuals with Internet addiction react differently on stimuli, which explicitly show Internet-related content and have difficulty in inhibiting responses only to those stimuli, as it has been shown in substance-dependent individuals (e.g., Pike et al., 2013).”

“The excessive Internet users in the study by Sun et al. (2009) had problems in performing the Iowa Gambling Task, indicating decision-making deficits, which had frequently been linked to addictive behaviors (Bechara, 2005).”

“…facets, such as low self-efficacy, shyness, stress vulnerability, and procrastination tendencies (Whang et al., 2003; Chak and Leung, 2004; Caplan, 2007; Ebeling-Witte et al., 2007; Hardie and Tee, 2007; Thatcher et al., 2008; Kim and Davis, 2009) are predisposing factors for developing a GIA.”

“One example for such a specific predisposition is a high sexual excitation (Cooper et al., 2000a,b; Bancroft and Vukadinovic, 2004; Salisbury, 2008; Kafka, 2010), which makes it more likely that an individual uses Internet pornography, because he/she anticipates sexual arousal and gratification…”

“Features of Internet addiction may co-vary positively with both positive expectancies (e.g., to experience pleasure) and avoidance expectancies (e.g., to escape from reality) on a bivariate level (Brand et al., 2014a; Lee et al., 2014; Turel et al., 2011; Xu et al., 2012).”

“Studies have utilized brain imaging techniques to determine the involvement of neural circuits in executive functions and craving behavior in individuals who experience a lack of control over their Internet and games time (Brand et al., 2014).”