Bispectrum analysis of EEG during observation and imagination of hand movement

This paper explores the use of bispectrum analysis of electroencephalogram (EEG) signals in estimation of imagination and observation of hand movements. Five different tasks were observed and subsequently performed in separate runs of 10 trials. Subjects were asked to observe and subsequently perform task on the presentation of an audio cue (both at the start and end of session). The acquired EEG signals after averaging in time domain were analyzed using bispectrum. The result shows bispectrum analysis of EEG signals provide a way to discriminate mental representation during observation and imagination of hand movement. Our preliminary investigation, have shown the ability of bispectrum in detecting non-linear phase coupling between alpha and beta rhythms during observation and imagination of hand movement. Further, different bispectral peaks (for tasks with and without prior visual representation) have reinforced our belief that visual representation of motor acts make difference during motor imagination.