Poster A105, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Response Inhibition Deficits Are Associated with Disrupted Intrinsic Connectivity of the Motor Network after Pediatric Traumatic Brain Injury
Jaclyn Stephens1,2, Cindy Salorio1,2, Mary Beth Nebel1,2, Stewart Mostofsky1,2, Stacy Suskauer1,2; 1Kennedy Krieger Institute, 2Johns Hopkins School of Medicine
Poor response inhibition is a hallmark of pediatric traumatic brain injury (TBI). We assessed response inhibition with commission error rates on Simple (minimized cognitive demands) and Motivation (monetary reward) Go/No-Go tasks, comparing 17 children with chronic (> one year) TBI and 14 matched, uninjured peers. We used resting state fMRI to examine whole-brain intrinsic connectivity of the motor network as derived from the averaged time course of bilateral primary motor cortex seeds. Between-group connectivity contrasts were completed (voxel-level threshold p<0.001, family wise error correction) to identify regions of interest (ROI) for brain-behavior correlations. Independent sample t-tests compared Go/No-Go performance and connectivity at the ROI-level. Pearson correlations examined relationships between intrinsic connectivity at the ROI-level and Go/No-Go performance. Children with TBI had poorer performance on Simple (p = .02) and Motivation tasks (p = .03). They also had reduced functional connectivity between the motor network and left caudate voxels (p = .02) in whole-brain contrasts, lower connectivity between the motor network and left caudate ROI (p = .02), and trending lower connectivity between the motor network and right caudate ROI (p = .07). In the TBI group, lower motor network to left caudate connectivity related to poorer Simple task performance (p = .03), whereas lower motor network to right caudate connectivity related to poorer Simple (p = .01) and Motivation (p = .02) task performance. No brain-behavior relationships existed among controls. These results are coherent with previous pediatric TBI literature and suggest that disrupted intrinsic connectivity may underlie response inhibition deficits.
Topic Area: PERCEPTION & ACTION: Motor control