(a) MEG Sternberg working memory task. Yellow letters represent probe trials. White numbers represent stimulus durations and ISIs (ms). (b) Channel montage for all eight regions: left frontal, midline frontal, right frontal, left temporal, right temporal, left parietal, right parietal, central-midline. (c) Averaged response to probe trials for all 160 channels for one subject. (d) Channels selected for one of the eight regions. (e) RMS computed for one of the eight regions based on selected channels. (f) Average amplitude of RMS in 50-ms time windows for ANCOVA analyses.