Infra-slow electroencephalogram power associates with reaction time in simple discrimination tasks

Abstract

Infra-slow (<0.1 Hz) electroencephalography (EEG) activity is recently thought to be an important clue for the elucidation of the default mode network (DMN), one of large-scale brain networks, which is known to activate during relaxed non-task state. On the other hand, the dynamics of the infra-slow EEG during performing cognitive tasks has not been well evaluated, because it has been excluded in the conventional EEG analysis. In this study, we evaluated infra-slow EEG during visual and auditory discrimination and found that the increase in the infra-slow EEG power distributed widely over scalp region was significantly correlated with the increase of reaction time of both tasks. Importantly, this result is consistent with the interpretation that the infra-slow EEG activation reflects DMN activation. It is suggested that the infra-slow EEG power is available for an index for the DMN activation during performing cognitive tasks.