Motor deactivation in the human cortex and basal ganglia.

We used a functional magnetic resonance imaging motor activation paradigm for both hands and functional connectivity analyses to investigate motor deactivation. These analyses revealed ipsilateral (to the task) postcentral gyrus connectivity with the ipsilateral primary motor cortex as well as contralateral cerebellum for both hands. Analyses using default-mode network nodes as seed regions revealed connectivity patterns similar to previous studies of the default network and therefore provide evidence that this network is demonstrable using a synchronized motor activation paradigm. We did not find evidence suggesting that motor deactivation represents modulation of the default mode network. Therefore, motor deactivation is likely a motor-specific process. Finally, we found no evidence of basal ganglia circuit deactivation, which suggests that the two-pathway hypothesis of frontal-subcortical circuit function may be incomplete.