title: Chronometric electrical stimulation of right inferior frontal cortex increases motor braking.
abstract: The right inferior frontal cortex (rIFC) is important for stopping responses. Recent research shows that it is also activated when response emission is slowed down when stopping is anticipated. This suggests that rIFC also functions as a goal-driven brake. Here, we investigated the causal role of rIFC in goal-driven braking by using computer-controlled, event-related (chronometric), direct electrical stimulation (DES). We compared the effects of rIFC stimulation on trials in which responses were made in the presence versus absence of a stopping-goal ("Maybe Stop" [MS] vs "No Stop" [NS]). We show that DES of rIFC slowed down responses (compared with control-site stimulation) and that rIFC stimulation induced more slowing when motor braking was required (MS) compared with when it was not (NS). Our results strongly support a causal role of a rIFC-based network in inhibitory motor control. Importantly, the results extend this causal role beyond externally driven stopping to goal-driven inhibitory control, which is a richer model of human self-control. These results also provide the first demonstration of double-blind chronometric DES of human prefrontal cortex, and suggest that--in the case of rIFC--this could lead to augmentation of motor braking.
authors: Psychology Department, University of California, San Diego, La Jolla, California 92093, and Department of Neurosurgery, University of Texas Medical School at Houston, and Memorial Hermann Hospital, Texas Medical Center, Houston, Texas 77030.
authors: Jan R
authors: JR
authors: Wessel
authors: Christopher R
authors: CR
authors: Conner
authors: Adam R
authors: AR
authors: Aron
authors: Nitin
authors: N
authors: Tandon
mesh_terms: D000328:Adult; D004558:Electric Stimulation / Q000379:methods*; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology
keywords: cognitive control; direction electrical stimulation; electrocorticography; inhibitory control; stop-signal task