Dissociating Two Stages of Preparation in the Stop Signal Task Using fMRI.

ABSTRACT: Often we must balance being prepared to act quickly with being prepared to suddenly stop. The stop signal task (SST) is widely used to study inhibitory control, and provides a measure of the speed of the stop process that is robust to changes in subjects' response strategy. Previous studies have shown that preparation affects inhibition. We used fMRI to separate activity that occurs after a brief (500 ms) warning stimulus (warning-phase) from activity that occurs during responses that follow (response-phase). Both of these phases could contribute to the preparedness to stop because they both precede stop signals. Warning stimuli activated posterior networks that signal the need for top-down control, whereas response phases engaged prefrontal and subcortical networks that implement top-down

SUBMITTER: Chevrier A 

PROVIDER: S-EPMC4481508 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature