Frontal and motor cortex contributions to response inhibition: evidence from electrocorticography

Abstract

Changes in the environment require rapid modification or inhibition of ongoing behavior. We used the stop-signal paradigm and intracranial recordings to investigate response preparation, inhibition, and monitoring of task-relevant information. Electrocorticographic data were recorded in eight patients with electrodes covering frontal, temporal, and parietal cortex, and time-frequency analysis was used to examine power differences in the beta (13-30 Hz) and high-gamma bands (60-180 Hz). Over motor cortex, beta power decreased, and high-gamma power increased during motor preparation for both go trials (Go) and unsuccessful stops (US). For successful stops (SS), beta increased, and high-gamma was reduced, indexing the cancellation of the prepared response. In the middle frontal gyrus (MFG), stop signals elicited a transient high-gamma increase. The MFG response occurred before the estimated stop-signal reaction time but did not distinguish between SS and US trials, likely signaling attention to the salient stop stimulus. A postresponse high-gamma increase in MFG was stronger for US compared with SS and absent in Go, supporting a role in behavior monitoring. These results provide evidence for differential contributions of frontal subregions to response inhibition, including motor preparation and inhibitory control in motor cortex and cognitive control and action evaluation in lateral prefrontal cortex.

Physiological Markers of Motor Inhibition during Human Behavior

“…Several attempts have been made to link specific electrophysiological signatures to inhibitory mechanisms (see [10, 140] for reviews). The initiation of voluntary movements is associated with desynchronization of activity in the beta frequency band (13–30 Hz) in electrocorticography (ECoG) and scalp electroencephalography (EEG) recordings over motor cortex [141–143].…”

Oscillatory Dynamics of Prefrontal Cognitive Control

“…Neither predicted deviants nor standards elicited any meaningful PFC activation, while sensory areas did not distinguish between predicted and unpredicted deviants. Notably, the PFC became active when unexpected errors were detected [32]. This raises the question how the PFC encodes predicted task contexts and other behaviorally relevant rules.…”

Establishing a Right Frontal Beta Signature for Stopping Action in Scalp EEG: Implications for Testing Inhibitory Control in Other Task Contexts

“…Moreover, electrocorticography (ECoG) studies, which record electroencephalography (EEG) signals directly from the surface of the brain, have shown that one electrophysiological signature of stopping is a power increase in the rIFC for successful vs. failed stop trials, before the time of stopping elapses i.e. Stop Signal Reaction Time, SSRT (Swann, et al, 2009; Wessel, et al, 2013) [but see Fonken et al (2016)]. These power increases occurred in the beta band, as do power increases in the basal ganglia during stopping (e.g.…”