PMC

Means of problematic internet use in the four work-time internet use groups and four leisure-time internet use groups. WG1: work-time internet use group 1 (<5 h/w); WG2: work-time internet use group 2 (5–13.99 h/w); WG3: work-time internet use group 3 (14–27.99 h/w); WG4: work-time internet use group 4 (28–60 h/w); LG1: leisure-time internet use group 1 (<4 h/w); LG2: leisure-time internet use group 2 (4–10.99 h/w); LG3: leisure-time internet use group 3 (11–20.99 h/w); LG4: leisure-time internet use group 4 (21–84 h/w). * p < 0.05, ** p < 0.001.

Average predicted traffic for the 50 most popular Internet cigarette vendor websites, adjusted for Internet traffic growth (March 2004 to January 2007).

(A) Positive Internet Game Literacy Scale scores. (B) Negative Internet Game Literacy Scale scores.

The proposed model on the development and maintenance of generalized and specific Internet addiction. (A) Demonstrates the proposed way of using the Internet as a tool for dealing with personal needs and goals in everyday-life. In (B), the proposed mechanisms underlying generalized Internet addiction (GIA) are summarized. (C) Illustrates the proposed processes involved in specific Internet addiction (SIA), for example the addictive use of certain Internet applications, such as gaming, cybersex, communication, and so on. We argue that in both conditions, GIA and SIA, reductions in prefrontal control processes are related to the individuals’ loss of control over their Internet use. As outlined in Section “General Comments on Neuropsychological Research in Addiction,” control processes are related to higher-order cognitive functions. We believe that if an individual with GIA faces the situation that he/she is confronted with the possibility to go online (or to use a certain Internet application in an individual with SIA), these cues are so strong that the individual reacts relatively automatically with a wanting reaction. Cognitive control over this reaction is difficult if the expectancies that using the Internet would reduce craving and result in positive and/or negative reinforcement. We will summarize neuropsychological and neuroimaging findings on the link between executive control functions, cue-reactivity, and an addicted use of the Internet in Sections “” and “.”