Mechanisms and Dynamics of Cortical Motor Inhibition in the Stop-signal Paradigm: A TMS Study

■ The ability to stop ongoing motor responses in a splitsecond is a vital element of human cognitive control and flexibility that relies in large part on prefrontal cortex. We used the stop-signal paradigm to elucidate the engagement of primary motor cortex (M1) in inhibiting an ongoing voluntary motor response. The stop-signal paradigm taps the ability to flexibly countermand ongoing voluntary behavior upon presentation of a stop signal. We applied single-pulse TMS to M1 at several intervals following the stop signal to track the time course of excitability of the motor system related to generating and stopping a manual response. Electromyography recorded from the flexor pollicis brevis allowed quantification of the excitability of the corticospinal tract and the involvement of intracortical GABABergic circuits within M1, indexed respectively by the amplitude of the motor-evoked potential and the duration of the late part of the cortical silent period (SP). The results extend our k...

• Type: Journal
• Year: 2010
• Where: JOCN
• Authors: Wery P. M. van den Wildenberg, Borís Burle, Franck Vidal, Maurits W. van der Molen, K. Richard Ridderinkhof, Thierry Hasbroucq
• Keywords: JOCN 2010, Motor Response, Stop Signal, Stop-signal Paradigm