Figure 4. Cue-locked Parietal Delta.

Figure 4a shows event-related spectral perturbation (ERSP) time-frequency maps at the electrode CPz (Top) and topographic maps (the grand-average of delta ERSP power (1–3 Hz) at the 100 – 500 ms window following cue onset) (Bottom) depicting cue-locked reward-anticipation EEG activity. Specifically, ERSP activity during Reward and No-Reward trials is depicted in the left and middle columns, respectively. The right column depicts paired t-tests’ (df = 36) p values (FDR corrected) for which Reward trial ERSP power was significantly different from No-Reward trial ERSP power. For these p-value maps, the time-frequency map shows p values at each time and frequency at CPz, while the bottom topo map shows p values at the delta (1–3 Hz) band at the 100 – 500 ms window following cue onset at every electrode. The time scale in the time-frequency maps is relative to the cue onset. Note that we computed time-frequency maps from −830 to 1828 ms (see text). However, for visual proposes, we only show −300 to 1000 ms relative to the cue onset here, given our focus on the time period right after cue onset. Note also that heat-map scales for time-frequency and topographic maps are different. Figure 4b depicts ERSP at the delta band (1–3 Hz) at CPz. Figure 4c shows a scatterplot between Motivated-Learning Inaccurate Estimation (i.e., during the last experimental block) and cue-locked delta ERSP (1–3 Hz between 100 – 500 ms) at CPz. In this scatterplot, cue-locked delta ERSP is separated to the ERSP during Reward Trials and No-Reward Trials. Gray areas indicate the confident interval of 95% around the regression line.