Neural networks of motor and cognitive inhibition are dissociated between brain hemispheres: an fMRI study

Paradigms exploring cognitive inhibition involve motor responses, which may confound the results. We compare cognitive inhibition activation obtained without motor involvement, to motor inhibition alone, in a group of young right-handed volunteers, utilizing a classical color Stroop task (CST), and a Stop Task. Comparison of fMRI activation was performed contrasting lateralization indexes of different Regions of Interest (ROI). Cognitive inhibition showed left brain lateralization, while motor inhibition showed right brain lateralization. Homologue brain areas involved the inferior frontal gyrus, inferior parietal lobule, middle temporal gyrus, and anterior cingulate gyrus. These circuitries appear to support that inhibition is a complicated function involving working memory, attention, semantic decision, and motivation modules.