Effects of Rest-Break on mental fatigue recovery based on EEG dynamic functional connectivity

Abstract

In recent years, brain functional connectivity (FC) plays an important role in the field of cognitive state monitoring and has attracted the attention of many researchers. In this study, we explored the effects of rest on the brain by designing a two-session experiment with 20 healthy participants. In session one, subjects were required to do four consecutive experiments (No-rest session), whereas, in session two, subjects were required to do a mid-task break by adding a rest run in the middle of consecutive tasks (Rest session). To reveal the changes in brain FC over long timescales, a dynamic brain network with three frequency bands (theta, alpha, and beta band) was established. Compared to the pre-task rest runs, a significant decrease in temporal global efficiency was observed in theta and alpha bands in post-task rest (theta: pre-task rest > post-task rest, F1,19 = 4.501, p = 0.047, η2 = 0.010; alpha: pre-task rest > post-task rest, F1,19 = 4.686, p = 0.043, η2 = 0.027) whereas there was a significant increase in temporal local efficiency in the theta band (pre-task rest < post-task rest, F1,19 = 7.646, p = 0.012, η2 = 0.043). Such results manifested that the temporal local efficiency had a positive correlation with the duration of the task. In addition, we use a two-way repeated-measures ANOVA for the temporal closeness centrality of each channel. In general, significant differences (including block effect, session effect and interaction effect) are found in three frequency bands, and these channels are mainly distributed in frontal and occipital regions. Overall, this work is an expansion of EEG-based static brain network fatigue analysis and the results manifest that the temporal local efficiency of the brain increases in the process of fatigue to overcome the decline of the overall efficiency of the brain.