Brain activity during the CPT task as compared with fixation depicted for the overall group (N = 29), the low-grade HI group (n = 16), and high-grade HI group (n = 13). Sites with significantly greater activation during task relative to fixation (CPT > fixation) are shown in green for the overall group, yellow for the low-grade HI group, and violet for the high-grade HI group. Random-effects analysis, p ≤ .05, voxel-corrected FWE, and cluster size of ≥5 voxels. Results are shown on an average image created from a template. Images are shown in neurological convention (left on left).