Topography and timing of activity in right inferior frontal cortex and anterior insula for stopping movement

Abstract

Stopping incipient action activates both the right inferior frontal cortex (rIFC) and the anterior insula (rAI). Controversy has arisen as to whether these comprise a unitary cortical cluster-the rIFC/rAIor whether rIFC is the primary stopping locus. To address this, we recorded directly from these structures while taking advantage of the high spatiotemporal resolution of closely spaced stereo-electroencephalographic (SEEG) electrodes. We studied 12 patients performing a stop-signal task. On each trial they initiated a motor response (Go) and tried to stop to an occasional stop signal. Both the rIFC and rAI exhibited an increase in broadband gamma activity (BGA) after the stop signal and within the time of stopping (stop signal reaction time, SSRT), regardless of the success of stopping. The proportion of electrodes with this response was significantly greater in the rIFC than the rAI. Also, the rIFC response preceded that in the rAI. Last, while the BGA increase in rIFC occurred mainly prior to SSRT, the rAI showed a sustained increase in the beta and low gamma bands after the SSRT. In summary, the rIFC was activated soon after the stop signal, prior to and more robustly than the rAI, which on the other hand, showed a more prolonged response after the onset of stopping. Our results are most compatible with the notion that the rIFC is involved in triggering outright stopping in concert with a wider network, while the rAI is likely engaged by other processes, such as arousal, saliency, or behavioral adjustments.

Cortical network mechanisms of response inhibition

“…Contrasting sSTOP trials with uSTOP or GO trials in non-selective SSTs entails several issues (see discussion below, Selective stopping task suggests that rIFG does not serve an attentional role). A third reason is that results may depend on the way onset latencies are defined (see discussion of limitations by Bartoli et al, 2018). We therefore validated our findings based on time-frequency representations (TFR) by a second, orthogonal approach.…”

“…Sánchez-Carmona et al (2016) used EEG, but did not analyze the temporal activation order of both regions. However, the majority of studies providing high temporal resolution relied on a standard SST (Allen et al, 2018;Bartoli et al, 2018;Fonken et al, 2016;Jha et al, 2015).…”

Proactive and reactive cognitive control rely on flexible use of the ventrolateral prefrontal cortex

“…Thus, these findings provide preliminary evidence that the aI/VLPFC proactively modulates or potentially suppresses subsequent neural activity (motor programs) during B probe periods in some individuals (Aron, ; Chikazoe et al, ; Jahfari, Stinear, Claffey, Verbruggen, & Aron, ), leading to a high degree of variability in neural responses when the group is examined as a whole. However, there is increasing evidence that the aI and VLPFC are functionally heterogeneous and may play differential roles in detecting behaviorally salient events or implementing inhibitory control, both of which may occur in a proactive or reactive fashion (Bartoli, Aron, & Tandon, ; Cai, Ryali, Chen, Li, & Menon, ). Similar to previous results, behavioral metrics of proactive cognitive control were related to working memory capacity (Kane & Engle, ; Redick, ; Redick & Engle, ), but no association was observed with measures of neural variability.…”

Action Control Deficits in Patients With Essential Tremor

“…However, what aspect of stop-signal performance is reflected by each of those nodes in the circuitry in inhibitory action control (actual inhibitory process versus processing salient cues or updating of action plans), their temporal activation profile related to action cancelation, and whether the inhibition network is right-lateralized is still under debate (Aron et al, 2006; Bartoli, Aron & Tandon, 2018; Hampshire et al, 2010; Hung, Yamak, Gaillard & Arsalidou, 2018). …”