The Efficacy of Transcranial Direct Current Stimulation Effect on Vigilance Decrement Predicted by a Fuzzy Logic Model

This study aimed to assess the efficacy of transcranial direct current stimulation (tDCS) on vigilance decrement. We proposed a three-layer fuzzy logic model to explore the feasibility of utilizing the three types of EEG features (amplitudes and latencies of ERPs, power ratio) to predict the behavioral impairment-related vigilance decrement. Eleven participants received 20 min, 1mA active or sham tDCS during the interval of 2 runs of 30-min vigilance task, while the EEG data were recorded during the vigilance task. Considering the time-on-task behavioral impairment effect of vigilance decrement, each run was divided into six 5-min-long bins. Therefore, the first and last 5-min bins were defined as the vigilance and fatigue states, respectively. We achieved an average classification accuracy (90.91%) between vigilance, moderate vigilance, and fatigue states. The results also showed that tDCS can remediate the vigilance decrement effect.