Fig. 1.

Mean power spectra computed over all sites, and mean coherence and mean Granger causality spectra computed over all significant site pairs. Results are from monkeys GE (black curves) and LU (gray curves) during the wait period of the task (Methods). The overall dominance of activity near 20 Hz in the power (A), coherence (B), and Granger causality (C) spectra indicates that a beta-synchronized network of neuronal assemblies supported directionally specific Granger causal influences in the sensorimotor cortex.