The SSD was tuned for each rat so that it would erroneously continue its movement (STOP-Failure) or successfully stop on approximately equal numbers of trials. During each test session, SSD was held constant to facilitate analysis of the electrophysiological data triggered on the GO and STOP cues. Rats received implants containing 21 individually drivable tetrodes (Gage et al., 2010). For the Immediate- and Deferred-GO tasks, tetrodes were targeted to right M1, STR, and GP. For rats trained on the Go/NoGo and Stop-signal tasks, the left

BG (STR, GP, STN, and SNr) were targeted. Ipsilateral prefrontal ECoGs were recorded with skull screws in contact with the brain (AP 4.5 mm, ML 1.5 mm relative to bregma). All signals were referenced to Gefitinib solubility dmso a skull screw on the midline 1 mm posterior to lambda (between cerebral cortex and cerebellum). We have found previously that this reference location is not itself associated with substantial beta power, that would produce artificially elevated beta coherence estimates between all pairs of forebrain locations (Berke, 2009). Analyses were performed using Matlab (Mathworks, Inc., Natick, MA). Gabor power spectrograms

were computed by convolving LFPs with Gaussian-tapered (50 ms standard deviation) complex sinusoids of integer frequencies from 1 to 100 Hz, and taking the logarithm of the squared magnitude of the resulting time-series. To generate Figures 1C and Figures

4C, the spectrograms for each recording session were averaged. To generate power comodulograms (Figures 2D and Figures S3B), Pearson’s correlation coefficient IWR-1 nmr was calculated between these same time series for each pair of recording sites. This resulted in a not 100 × 100 grid with each point having a value ranging from −1 (perfect anticorrelation of power at two frequencies) to +1 (perfect correlation of power at two frequencies). Only epochs during which the rat was engaged in the task (from initial nose poke to trial completion) were included. Power spectra (Figure 2C) were calculated for each trial, averaged across trials to give a mean spectrum at each recording site for each session, and smoothed with a three-point rectangular sliding window. To calculate coherence spectra, for each trial we calculated the cross-spectrum between each pair of recording sites. Session-wide coherence was then calculated as the squared magnitude of the averaged trial-by-trial cross spectra normalized by the product of the average autospectra (Figure 2E). See Figures 1D, Figures 3B, 3E; Figures 4D; Figures S2, S5. LFPs were zero-phase filtered between 15–25 Hz and the analytic signal was calculated using the Hilbert transform. The squared magnitude of the analytic signal is a continuous measure of beta power, and continuous beta phase was extracted as the argument of the analytic signal.