Analysis of loss of alertness due to cognitive fatigue using Motif Synchronization of EEG records

Continuous and repetitive performance of cognitive tasks is likely to cause a change in the alertness levels of an individual. The present paper investigates the changes in EEG as a marker of alertness during an experiment designed to induce cognitive fatigue in subjects by continuous and repetitive performance of standard neuropsychological tests. Electroencephalogram (EEG), speech data and high-speed ocular images are recorded during the task set comprising of an Auditory Response Test (ART) Psychomotor Vigilance Test (PVT), a Letter Counting (LC) task, and a variant of the Stroop Task. EEG recorded during the ART is analyzed in the present work. Variation in network parameters in brain networks formed from the EEG records using the Motif Synchronization technique is employed to trace the change in alertness levels of subjects due to increase in cognitive fatigue.