How oscillatory activity shapes the functional architecture of the working brain
The working brain is composed of multiple networks which must be flexibly engaged and disengaged. How is this functional architecture shaped? Recent electrophysiological studies strongly suggest that networks not important for a given task are disengaged by an increase in oscillatory alpha activity (8-13 Hz). We propose that active processing, reflected by neuronal synchronization in the gamma band (30-150 Hz), is directed to task-relevant networks by blocking off task-irrelevant regions by means of alpha activity. A number of EEG and MEG studies on perception, attention and memory support this notion. This insight points to a new framework for understanding neuronal processing in which the disengagement of irrelevant networks by oscillatory alpha activity is a necessity for shaping the functional connectivity in order to ensure optimal task performance.