Stop-Signal Task

Synonyms

Response inhibition task; SSRT

Definition

A neurocognitive task designed to provide a sensitive measure of the time taken by the brain to inhibit or suppress inappropriate motor responses. The stop-signal paradigm was originally developed by Gordon Logan in the 1980s, based on a cognitive task first used by Lappin and Erikson in 1966. Versions of the task have been developed both for humans and rats. The stop-signal reaction time (SSRT) task not only provides measures of reaction times and accuracy, but importantly also the latency to inhibit a prepotent response (SSRT). The stopping process is not directly observable and has to be estimated from a stochastic model, the so-called “race model.” The model derives the SSRT from the distribution of “go” reaction times and the observed probability of responding on “stop” trials for a given stop-signal delay. The estimated SSRT gives a measure of the duration of the inhibitory process, which starts from the presentation of stop...