Figure 9. Time course of the beta power and burst rate throughout trial performance and following reward feedback.
(A) Time course of the feedback-locked beta power during sequence performance in the learning blocks, shown separately for anx1, anx2 and control groups. Average across sensorimotor and prefrontal electrode regions as in panel (B). Shaded areas indicate the SEM around the mean. Participants completed sequence2 on average between 720 (30) and 5350 (100) ms, denoted by the top gray box. The STOP signal was displayed 7000 ms after the GO signal, and was followed at 9000 ms by the feedback score. This representation shows two distinct time windows of significant differences in beta activity between the anx1 and control groups: at the end of the sequence performance and subsequently following feedback presentation (, respectively, denoted by the purple bar at the bottom). Anx2 participants also exhibited an enhanced beta power towards the end of the sequence performance (). (B) Time course of the rate of longer ( ms) oscillation bursts during sequence performance in the learning blocks. Anx1 participants exhibited a prominent rise in the burst rate 400–1600 ms following the feedback score, which was significantly larger than the rate in control participants (). Data display the mean and ± SEM. The topographic map indicates the electrodes of significant effects for panels (A–C) (). (C) Same as panel (B) but showing the rate of shorter beta bursts ( ms) during sequence performance in the learning blocks. Between-group comparisons demonstrated a significant drop in the rate of brief oscillation bursts in anx1 participants relative to control participants at the beginning of the performance (), but not after the presentation of the feedback score. In all panels, the traces of the mean power and burst rates were displayed after averaging across the significant sensorimotor and prefrontal electrodes shown in the inset in panel (B).