Event-related fMRI of saccadic response inhibition

Abstract

Inhibition of on-going or planned movements as well as monitoring errors is essential for adaptation to changing environments. We performed event-related functional MRI to examine neural correlates of inhibition and error processing in a saccadic Go/NoGo task. Contrary to the procedure in block designs, the BOLD response is recorded in each trial type separately, thus allowing us to sort trials depending on whether the trial was correct or incorrect. Gradient-echo EPI was performed on a 1.5 T scanner with a TR of 3 sec and 24 slices. Saccades and fixations were monitored using the MR-Eyetacker. Results from 7 subjects reveal NoGo dominant activity in dorsolateral prefrontal cortex (BA 9, 10, 46) and in the anterior cingulate (BA 24). Errors of commission on NoGo trials evoked stronger activation in right frontal operculum (BA 47), right DLPF (BA 9) and left orbiofrontal (BA 11) cortex compared to that found in Go trials.