Time-frequency effects for reward outcome.

<p>SPM-based analyses across all sensors and time-points revealed main effects of drug group (levodopa, placebo) at left frontal sensors for both the low beta band (peak at 398 ms; nearest sensor: MLF65) (A) and high beta band (peak at 762 ms; same nearest sensor) following outcome presentation (D). Both effects were driven by reduced beta power in the levodopa group compared to the placebo group (C and F). In addition, power in the low beta band decreased as a function of outcome magnitude (i.e., from high to low magnitude) at the peak voxel showing the group effect (C). Left columns show statistical parametric maps of the F-statistics, middle columns show the time-frequency plots as extracted from the nearest channel, and right columns show the effects for each condition at the peak time point as extracted from voxel space. Dashed boxes in B and E indicate the low (13–20 Hz) and high (20–30 Hz) beta band, respectively. Error bars in C and F denote one SEM.