Figure 3.

Selection of impulsive choice across subjects: fMRI correlation analysis. Brain regions showing a significant positive correlation between activity during subjective Now versus Later decision making and ICR. Brain activity indices derived from the subjective choice contrast (W − CON); see Materials and Methods for greater detail. A, MNI space coordinates (x, y, z) and t values for the PPC (top; 66, −42, 44; t = 5.03), dPFC (middle; −22, 50, 44; t = 3.79), and PHG (bottom; 18, −4, −28; t = 4). Criterion threshold was p < 0.001 (uncorrected), with a minimum cluster size of five contiguous voxels; results are shown at p < 0.005 for display purposes. These data also survived permutation-based voxelwise correction of familywise error (p < 0.05). L, Left. B, Corresponding correlation plots for each subject's contrast parameter estimate (an index of relative activity) versus ICR for the peak of each region identified at left; the peak regression statistic is displayed in each plot.