Neural and behavioral markers of mental fatigue and fatigability in athletes: an EEG study using single and mixed...

This study examined time-dependent neural correlates and behavioral markers of mental fatigue and fatigability in athletes using single and mixed cognitive task paradigms with electroencephalography (EEG). Forty athletes completed Stroop, Flanker, Arithmetic, or mixed-task paradigms. EEG data were analyzed using power spectral density (PSD) in the theta, alpha, and beta frequency bands and event-related potential (ERP) analysis focusing on P300 amplitude and latency. Behavioral measures included reaction time, error rate, and subjective fatigue assessed using a Visual Analog Scale. The results showed that subjective fatigue increased significantly over time across all task conditions (p < 0.001). Behavioral performance differed across tasks, with higher error rates and longer reaction times in the Arithmetic and mixed-task conditions compared to the Stroop and Flanker tasks (p < 0.001). PSD analyses revealed significant task-related differences (p < 0.05), including higher frontal theta power during the Arithmetic task and lower posterior theta power during the mixed-task condition. Alpha power increased significantly over time in posterior regions (p < 0.05). P300 amplitude decreased across time blocks in central, centroparietal, and parietal locations (p < 0.001), while P300 latency differed across tasks (p < 0.01). In conclusion, increased subjective fatigue and time-dependent changes in posterior EEG activity occurred without behavioral performance decline, supporting a distinction between mental fatigue and fatigability.