Source coherence is displayed in time-frequency space with the left motor cortex as source channel reference. Coherence occurs in the gamma range (maximum 0.25 at 38 Hz) between the left motor-cortex and the cerebellum around button press. Alpha coherence occurs before the visual stimulus suppresses the alpha rhythm. About 350-450 ms after the button press coherence occurs around 15 Hz between motor cortex and cingulate gyrus.
As compared to scalp coherence, source coherence displays are far more separated in space, time, and frequency after transforming the single trial activities into the brain using source montages.