Individual differences in the functional neuroanatomy of inhibitory control

Abstract

We combined the data of five event-related fMRI studies of response inhibition. The reanalysis (n = 71) revealed response inhibition to be accomplished by a largely right hemisphere network of prefrontal, parietal, subcortical and midline regions, with converging evidence pointing to the particular importance of the right frontal operculum.Functional differences were observed between the sexes with greater activity in females in many of these cortical regions. Despite the relatively narrow age range (18-46), cortical activity, on the whole, tended to increase with age, echoing a pattern of functional recruitment often observed in the elderly. More absentminded subjects showed greater activity in fronto-parietal areas, while speed of Go trial responses produced a varied pattern of activation differences in more posterior and subcortical areas. Although response inhibition produces robust activation in a discrete network of brain regions, these results reveal that individual differences impact on the relative contribution made by the nodes of this network. IntroductionDifficulty inhibiting inappropriate behaviours is characteristic of many psychological and psychiatric disorders ranging from the impulsivity of children with ADHD (Barkley, 1997), the loss of control exhibited by drug abusers (Fillmore and Rush, 2002;Kaufman et al., 2003), to the inappropriate stimulus-driven behaviour of brain-damaged individuals (Luria, 1966). Normal cognition is also subject to occasional inhibitory disruption as suggested by lapses in speech, action, thought and intention, wherein behaviour appears to be dictated by cue or by habit (Dempster and Brainerd, 1995). As a result of the apparent importance of this aspect of cognitive control, much effort has been expended in attempting to identify its neuroanatomical substrates. However, inhibitory control is a broad term incorporating cognitive (e.g., suppressing interference), perceptual/attention (e.g., ignoring distracters) and motor (e.g., response countermanding) domains. While the similarities and dissimilarities between these aspects of inhibition remain unclear (Bunge et al., 2002;Friedman and Miyake, 2004), it is the latter operationalisation that will be the focus here. A substantial body of evidence on motor inhibition now exists due, in part, to the relative ease of implementing experimental tests of this function. Previous neuroimaging research has converged on a discrete number of regions thought to be implicated in motor response inhibition including dorsolateral and ventrolateral prefrontal cortex, parietal cortex, midline regions including the anterior cingulate and pre-SMA, and there is also evidence for thalamic and subcortical involvement (Aron and Poldrack, 2006;Brass et al., 2001;Braver et al., 2001;Garavan et al., 1999;Menon et al., 2001;Rubia et al., 2001;Watanabe et al., 2002). More specifically, ventral regions of the right hemisphere appear to be particularly important; the frontal operculum has been implicated

Inhibition of action, thought, and emotion: A selective neurobiological review

“…First, recent evidence indicates that individual difference variables, including sex (e.g., Li, Huang, Constable, & Sinha, 2006;Garavan et al, 2006), age (e.g., Nielson, Langenecker, & Garavan, 2002) and genotypes (e.g., Pezawas et al, 2005), modulate inhibition-related functions and underlying neural circuitries. A better understanding of the modulatory effects of these variables, particularly with respect to their role in increasing vulnerability to psychopathology, is needed.…”

“…Functional neuroimaging studies reveal that nogo stimuli consistently elicit activity in a network of primarily right lateralized regions, including the VLPFC (Garavan, Hester, Murphy, Fassbender, & Kelly, 2006;Garavan, Ross, & Stein, 1999;Konishi, Nakajima, Uchida, Kikyo, Kameyama, & Miyashita, 1999;Liddle, Kiehl, & Smith, 2001;Menon et al, 2001), and the stop-signal task consistently reveals activity in the right VLPFC (Chevrier, Noseworthy, & Schachar, 2007;Rubia et al, 2001;Rubia et al, 2003). Interactions between the right VLPFC and subcortical structures may underlie response stopping.…”

Individual Differences in Nicotine Dependence, Withdrawal Symptoms, and Sex Predict Transient fMRI-BOLD Responses to Smoking Cues

“…There were some significant differences between the two samples (eg age) but there were also likely unmeasured differences (eg motivation to quit). While potentially problematic, as in previous aggregate analyses (Garavan et al, 2006), the inclusion of study as a nuisance variable should have accounted for variability due to these group differences. Future studies that evaluate how individual differences in motivation to quit, age, and other factors influence brain cue reactivity are warranted.…”

Effects of anxiety on task switching: Evidence from the mixed antisaccade task

“…More specifically, the ability to successfully select and execute the goal-relevant task set (while inhibiting or terminating the irrelevant) requires efficient use of working memory resources to exercise top-down attentional control (Baddeley, Chincotta, & Adlam, 2001;Hester & Garavan, 2005;Kane, Bleckley, Conway, & Engle, 2001;Meiran, 1996). Garavan et al (2006), using fMRI, found that the DLPFC had a supervisory role in working memory functions, such as representation of task set, stimulus appraisal, and response selection. Behavioral data (Hester & Garavan, 2005, Experiment 1) showed that increasing the number of items to be held in working memory decreased the speed at which participants switched attention from a primary working memory task to a secondary decision-making task.…”