Task-based functional connectivity in internet gaming disorder: A systematic review

Internet gaming disorder (IGD) is a global public health concern, with excessive gaming impacting daily life and causing psychological distress. However, the neural mechanisms in IGD are unclear, particularly how aberrant functional connectivity (FC) contributes to pathological behavioural dysfunction and how these processes align with leading neurobiological models of addiction.

This systematic review examines FC changes associated with behavioural symptoms of IGD through analysis of 29 studies conducted between 2013 and 2024. The review encompasses task-based functional magnetic resonance imaging paradigms across 1,129 IGD participants and 924 controls. Task paradigms were divided into three categories: 1) reward responsiveness; 2) executive control; 3) impulsivity and risk-taking.

During reward responsiveness tasks, IGD individuals demonstrated a pattern of increased FC of reward network regions, which was often accompanied by decreases in executive control network (ECN) FC. IGD individuals demonstrated both increases and decreases in ECN FC during executive control tasks. Higher impulsiveness and risk-taking behaviours were observed in IGD individuals, with increased reward network and ECN FC during related tasks.

Aberrant FC is a consistent feature of IGD, although the directionality of connectivity differences is varied. Impaired functioning may reflect reduced FC, while increased FC may indicate compensatory processes. Broadly, FC differences align with neurobehavioural models of addiction. However, a significant geographical bias was observed among studies, raising questions about generalisability. While these findings represent progress towards biomarker development in IGD, the methodological heterogeneity in task design and analysis limits definitive conclusions, highlighting the need for consensus in neuropsychiatric research.