Motor inhibition is among the most commonly studied executive functions in
attention-deficit/hyperactivity disorder (ADHD). Imaging studies using probes of
motor inhibition such as the stop signal task (SST) consistently demonstrate
ADHD-related dysfunction within a right-hemisphere fronto-striatal network that
includes inferior frontal gyrus and pre-supplementary motor area. Beyond
findings of focal hypo- or hyper-function, emerging models of ADHD
psychopathology highlight disease-related changes in functional interactions
between network components. Resting state fMRI (R-fMRI) approaches have emerged
as powerful tools for mapping such interactions (i.e., resting state functional
connectivity, RSFC), and for relating behavioral and diagnostic variables to
network properties. We used R-fMRI data collected from 17 typically developing
controls (TDC) and 17 age-matched children with ADHD (aged
8–13 years) to identify neural correlates of SST performance
measured outside the scanner. We examined two related inhibition indices: stop
signal reaction time (SSRT), indexing inhibitory speed, and stop signal delay
(SSD), indexing inhibitory success. Using 11 fronto-striatal seed
regions-of-interest, we queried the brain for relationships between RSFC and
each performance index, as well as for interactions with diagnostic status. Both
SSRT and SSD exhibited connectivity–behavior relationships independent
of diagnosis. At the same time, we found differential
connectivity–behavior relationships in children with ADHD relative to
TDC. Our results demonstrate the utility of RSFC approaches for assessing
brain/behavior relationships, and for identifying pathology-related differences
in the contributions of neural circuits to cognition and behavior