Introduction: Recent behavioural studies found that the extent of Problematic Internet use (PIU) and excessive smartphone use (ESU) have a long-term impact on chronic mental fatigue, but the effect of PIU and ESU on acute mental fatigue (AMF) is unrevealed until now. Similarly, the underlying neural background of AMF in PIU and ESU is not well understood, therefore the investigation of AMF with functional Magnetic Resonance Imaging (fMRI) is indispensable in these conditions.
Methods: Psychomotor Vigilance Task (PVT) was applied to induce AMF during fMRI. Blood-oxygen-level-dependent analysis was implemented to investigate brain activation changes during the PVT. Self-reported questionnaires were used to assess PIU, ESU, and the extent of subjective mental fatigue (SMF). Reaction time changes during PVT were measured to get an objective data of subjects’ AMF (OAMF).
Results: The extent of PIU and ESU predicts the degree of SMF, but no associations were found between OAMF and questionnaires’ score. Changes in brain activation in regions related to default mode network (DMN), attentional processes (the left precuneus and left cuneal cortex) and executive control functions (the left medial frontal gyrus) were associated with the extent of PIU. The degree of ESU showed no correlation with brain activation changes.
Discussion: Our findings highlight the impact of PIU on AMF. ​ According to previous results, we confirmed the altered functioning of brain areas connected to DMN in PIU and found some attentional and executive control regions whose activation changes during a cognitively demanding task are related to the extent of PIU.