Slow EEG fluctuation and heart rate variability reflects flexible adjustment to cognitive load

Abstract

We explored functions of the brain and autonomic activity accompanying cognitive load by examining effects of time series EEG power of the alpha band and heart rate variability (HRV) on task accuracy and reaction time during n-back tasks. Enhancement of the alpha power fluctuation at a very low frequency (0.01Hz) and greater HRV reflecting parasympathetic activity during a 3-back task were associated with higher task performance and stability of reaction time in the task, suggesting that ability of the brain to flexibly adjust behaviors to cognitive.