Functional connectivity during real vs imagined visuomotor tasks: an EEG study.

It is proposed that real and imagined movements activate identical neural networks. Cortical oscillatory activity is proposed as a mechanism through which distributed neuronal networks may bind into coherent ensembles and coupling of oscillators is used as a tool to investigate modulations of cortical connectivity. The aim of the present study was to test the hypothesis that, although the same brain network is involved in both real and imagined movements, the functional connectivity within the network differs. To do so, we measured interregional coupling, quantified using coherence between scalp EEG electrodes, during different periods of a prehension task during real and imagined movements. The results demonstrated a different pattern of coupling in the beta frequency range between electrodes overlying occipital and motor cortices during executed and imagined movements. These findings are consistent with the hypothesis that the neural networks during real and imagined movements are not identical.