Gray matter volume alterations in gaming disorder and pornography-use disorder

Structural brain changes may represent a possible link between problematic internet use (PUI) and behavioral alterations. They may reflect permanent adjustments of the brain circuitry that are not easily reversed. Previous metaanalyses (Qin et al., 2020; Solly et al., 2022; Sun et al., 2023; Wang et al., 2025; Zeng et al., 2023) have found decreased gray matter volume in the anterior cingulate cortex (ACC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC),the dorsolateral prefrontal cortex (DLPFC), and the dorsal striatum (DS). These brain areas are part of four networks believed to be associated in the development and maintenance of addictive behaviors: The reward network (ACC, OFC), the executive control network (DLPFC, SMA), the salience network (ACC), and the habit network (DS) (Antons et al., 2020). Changes in these networks may affect an individual’s (emotional) processing of stimuli as well as their decision making process and self-control abilities with regard to online engagement.
The association between problematic internet use and deficits in such executive functions has been demonstrated by S. M. Müller et al. (2025), including participants from multiple subprojects of the research group FOR2974 (Affective and cognitive mechanisms of specific Internet-use disorders (ACSID)) and for different types of internet-behaviors. Altered activation patterns of the executive control network (including DLPFC and SMA) have been observed in individuals with problematic behavior, while affective reactions such as cue reactivity and craving are related to the ACC, OFC, and the DS (Antons et al., 2020; Tian et al., 2023).
The present project aims at comparing gray matter volume in individuals with unproblematic use of gaming or pornography, risky use of gaming or pornography, and individuals with gaming disorder or pornography-use disorder. Additionally, we aim to correlate structural changes in designated areas with deficits in executive functions as well as measurements of affective reactions including cue reactivity and craving.
Measures for general executive functions include the Modified Card Sorting Test (MCST), and the Color-Word Interference Test (CWIT). Risky decision making will be assessed by the Game of Dice Task (GDT), while the Delay Discounting Task will assess participants’ tendency to favor small immediate over larger future rewards. To measure participants’ stimulus specific inhibitory control the affective shift go/ no-go task will be used, while logical reasoning skill swill be measured through the Leistungsprüfsystem part 4 (LPS-4), a German intelligence test battery. A cue reactivity paradigm will be used to measure participants urge with regard to specific behaviors under cue-exposure while the CASBA questionnaire will be used to measure craving.
This project represents additional analysis related to the linked two-part main registration 'Cue reactivity in gaming disorder and pornography-use disorder: Behavioral and neural correlates and effects of acute stress (FOR2974/RP4)' (DOI 10.17605/OSF.IO/4KJ2Y, 10.17605/OSF.IO/96738). All data used in the present project is part of this experiment.