Right hemispheric dominance of inhibitory control: An event-related functional MRI study

Abstract

Normal human behavior and cognition are reliant on a person's ability to inhibit inappropriate thoughts, impulses, and actions. The temporal and spatial advantages of event-related functional MRI (fMRI) were exploited to identify cortical regions that showed a transient change in fMRI signal after the withholding of a prepotent motor response. The temporal specificity of the event-related fMRI design also minimized possible contamination from response inhibition errors (i. e., commission errors) and other extraneous processes. Regions identified were strongly lateralized to the right hemisphere and included the middle and inferior frontal gyri, frontal limbic area, anterior insula, and inferior parietal lobe. Contrary to the prominence traditionally given to ventral frontal regions for response inhibition, the results suggest that response inhibition is accomplished by a distributed cortical network.

Impact of complex genetic variation in COMT on human brain function

“…Previous work has implicated ventrolateral PFC in inhibitory control 42,43 and set shifting, 44 and a right predominance in inhibitory control has been noted. 45 This raises the possibility that optimal dopaminergic tone may be especially relevant for inhibitory control and set shifting, prefrontally dependent cognitive functions that are well known to be impaired in schizophrenia 46,47 and dependent on COMT in rats. 7 Ultimately, a critical experimental test of the predictions derived here from imaging genetics is afforded by applying the results to association with clinical phenotypes.…”

Frontal recruitment during response inhibition in older adults replicated with fMRI

“…The Go/No-go task, administered with Superlab Pro 2.0, is described in detail elsewhere (Garavan et al, 1999;Nielson et al, 2002). Briefly, participants were required to press a button on a keypad by responding to alternating target letters (e.g., X, Y, X) such that they were required to inhibit a response to a letter the second time it was presented without an intervening other target letter.…”

Beyond common resources: the cortical basis for resolving task interference

“…Due to the relatively small number of error events, the deconvolved hemodynamic response for errors of commission (errors) included the errors committed over all load sizes. A nonlinear regression program determined the best-fitting gamma-variate function for these IRFs (Cohen, 1997) as previously described (Garavan et al, 1999). The area under the curve of the gamma-variate function was expressed as a percentage of the area under the baseline.…”

“…For example, the common load-sensitive region in the left prefrontal cortex has been implicated in both the maintenance of task goals during executive function tasks (MacDonald et al, 2000;Ullsperger and von Cramon, 2001) and WM rehearsal (Curtis and D'Esposito, 2003;D'Esposito et al, 1999;Rypma et al, 2002). Similarly, the dorsal ACC/pre-SMA region found to be common to both tasks has been widely identified across a range of tasks (Duncan and Owen, 2000), including inhibitory control (Garavan et al, 1999;Rubia et al, 2003) and WM (Kondo et al, 2004;Nyberg et al, 2003;Osaka et al, 2003). The finding that individual differences in this particular cingulate response were predictive of performance highlights it as a region critical to maintaining successful performance, though it is unclear what precise role the cingulate might be playing.…”