Alpha coherence predicts accuracy during a visuomotor tracking task

It has been shown that synchrony of neuronal oscillations plays a critical role in effective communication between functionally distinct brain areas involving motor-sensory integration. However, the patterns of cortico-cortical coupling and their relation to behavioural success are widely unknown. Here, we analysed changes in cortico-cortical coherence during an unimanual visuomotor task and their correlation with performance. A 28-channel-EEG was attained in 27 healthy subjects during the tracking of an irregularly fluctuating target on a screen by manipulating a force sensor with the right index finger and thumb. For oscillatory power in the alpha (8-12 Hz) and the lower beta-band (beta1, 13-20 Hz), we found a decrease in central and occipital areas during performance. Interregional coherence between contralateral frontal and central areas was enhanced in the alpha band. In beta1, we observed a marked increase of coherence in centroparietal regions of both hemispheres extending to occipital and frontal regions in beta2 (21-30 Hz). Most prominently, correlation analysis between alpha coherence and performance accuracy indicated that higher occipitocentral (i.e. visuomotor) coherence is associated with better visuomotor performance whereas high tracking error is associated with enhanced frontocentral coupling, suggesting additional activation of a frontoparietal control network. These results provide further evidence that coherent brain oscillations in alpha and beta bands significantly contribute to effective functional integration of visual and motor areas.