Inter-brain Mutual Information in Social Interaction Tasks

Using a dual EEG set-up, pairs of subjects jointly performed finger movement tasks under three conditions: intrinsic-ignore; in-phase - follow; and anti-phase - oppose their partner´s movement patterns. Group ICA was employed for signal decomposition in the 10-12 Hz range. Mutual information across dyads was estimated in tasks relative to baseline. Results demonstrated information encoding (between partners) in the anti-phase was two times more than the intrinsic which in turn expressed twice as much information content as the more automatic in-phase task. Topography of significant components revealed involvement of the frontal brain region in the intrinsic; both frontal and occipital brain regions in anti-phase suggesting decision making and employment of visual resources in these tasks.