Watching Positive Videos Facilitates Mental Fatigue Recovery: A Task fMRI Study

Timely intervention of mental fatigue is necessary to mitigate adverse consequences and promote rapid recovery. As the mobile internet and new media platforms rapidly expand, people are increasingly watching videos during breaks. While positive emotions are known to boost cognition and behavior, their potential role in fatigue recovery and the underlying neural mechanisms remain underexplored. The present study aims to investigate the effect of watching positive videos on fatigue-related behavioral performance and brain network reorganization during the psychomotor vigilance task (PVT). Specifically, 27 participants underwent a two-session within-subject experiment during fMRI scanning, where each session consisted of a 30-min PVT with a 3-min mid-task break involving either watching positive videos or only resting. Behaviorally, both break strategies could reverse fatigue state transiently, but the positive-break showed dominant immediate improvement on PVT reaction time compared to rest-break. Moreover, the brain networks assessment showed divergent global efficiency alternation manifested by the immediate improvement after break but significant decrease towards the end of tasks in the positive-break session, while showing an inverse trend in the rest-break session. Furthermore, the nodal measurement revealed the delayed effect of positive-break on nodal efficiency in the visual network. In sum, these findings underscore the potential of watching positive videos as a practical and accessible strategy for mitigating mental fatigue in demanding cognitive tasks, and indicate that watching positive videos not only affects the behavioral level, but also promotes fatigue recovery by dynamically regulating brain network, providing new evidence for understanding the emotion-cognition interaction underlying fatigue recovery.