FIGURE 6.

Beta band-mediated functional connectivity during the early cue period. (A) Channel groups (blue and red) with significant modulation of beta band power by cue condition during the early cue period of the task identified on the two-dimensional projection of the 204-gradiometer array (same as in Figures 3A,B). The functional connectivity between these two groups of channels was evaluated by computing for each trial the time-varying Pearson correlation coefficient of log-transformed beta band amplitude within a 180 ms window between each pair of channels from the posterior and left fronto-central groups. The Fisher’s z-transformed correlation coefficients were then averaged for each time point. (B) Cue aligned time series of average z-transformed correlation coefficient of beta amplitude between channel groups indicated in A, across cue condition and impulsivity group. The shaded bands show the standard error of the mean (Low impulsivity N = 24; High impulsivity N = 26). (C) Average z-transformed correlation of beta amplitude during the early cue period, across cue condition and impulsivity group. Error bars indicate the standard error of the mean. The correlation increased as number of cues increased and was smaller for the high impulsivity group than for the low impulsivity group across all cue conditions.