Function and Structure of the Right Inferior Frontal Cortex Predict Individual Differences in Response Inhibition: A Model-Based Approach

Abstract

The ability to suppress one's impulses and actions constitutes a fundamental mechanism of cognitive control, thought to be subserved by the right inferior frontal cortex (rIFC). The neural bases of more selective inhibitory control when selecting between two actions have thus far remained articulated with less precision. Selective inhibition can be explored in detail by extracting parameters from response time (RT) distributions as derived from performance in the Simon task. Individual differences in RT distribution parameters not only can be used to probe the efficiency and temporal dynamics of selective response inhibition, but also allow a more detailed analysis of functional neuroimaging data. Such model-based analyses, which capitalize on individual differences, have demonstrated that selective response inhibition is subserved by the rIFC. The aim of the present study was to specify the relationship between model parameters of response inhibition and their functional and structural underpinnings in the brain. Functional magnetic resonance imaging (fMRI) data were obtained from healthy participants while performing a Simon task in which irrelevant information can activate incorrect responses that should be selectively inhibited in favor of selecting the correct response. In addition, structural data on the density of coherency of white matter tracts were obtained using diffusion tensor imaging (DTI). The analyses aimed at quantifying the extent to which RT distribution measures of response inhibition are associated with individual differences in both rIFC function and structure. The results revealed a strong correlation between the model parameters and both fMRI and DTI characteristics of the rIFC. In general, our results reveal that individual differences in inhibition are accompanied by differences in both brain function and structure.

Electrophysiological evidence that inhibition supports lexical selection in picture naming

“…They concluded that their data confirmed the role of inhibition in reducing semantic interference during picture naming. It should be noted, however, that other investigators (e.g., De Bruin et al, 2014;Forstmann et al, 2008;Verhoef et al, 2009) have associated inhibition with right inferior frontal cortex rather than with orbitomedial prefrontal cortex, as de Zubicaray et al did.…”

“…Commonly used tasks include the stop-signal task, where participants plan a response but must withhold it when a stop signal is presented on a minority of the trials (Logan and Cowan, 1984); the anti-saccade task, where participants see a flashing cue on either the left or right side of a screen and have to shift their attention and gaze quickly to the opposite side of the screen (Hallett, 1978); and the Eriksen flanker task, a choiceresponse task where participants choose a response to a central target stimulus that is flanked by non-target stimuli that are congruent or incongruent with the response to the target (Eriksen and Eriksen, 1974). Forstmann et al (2008) distinguished between nonselective response inhibition, http://dx.doi.org/10.1016/j.brainres.2014.07.009 0006-8993/& 2014 Elsevier B.V. All rights reserved. n which is engaged to stop any planned motor response, and selective response inhibition, which is recruited to selectively inhibit specific responses competing with a target response.…”

“…Therefore, the slope of the slowest segment of the delta plot (i.e., the segment connecting the last two quantiles in the RT distribution) can indicate the recruitment of selective inhibition (Burle et al, 2002;Forstmann et al, 2008). Shallower or more negative slopes suggest that stronger topdown inhibition is applied (e.g., Forstmann et al, 2008;Ridderinkhof, 2002;Van den Wildenberg et al, 2011).…”

“…The component of central interest to the present study is the N2, a negative going ERP component that occurs between 200 and 400 ms after stimulus onset. Although there are various forms of the N2 that can be elicited in different tasks (see Folstein and Van Petten, 2008, for review), of particular interest in the current study is the N2 elicited in tasks requiring response inhibition, which has a frontal-central to right-frontal scalp distribution, and has been associated with activity in the medial prefrontal and right inferior frontal cortices (e.g., Forstmann et al, 2008;Van den Wildenberg et al, 2011;Verhoef et al, 2009). For instance, in the go/no-go task, a larger N2 is typically found on no-go relative to go trials, suggesting that the N2 reflects the successful inhibition of the response (e.g., Bruin et al, 2001;Carriero et al, 2007;Dong et al, 2009;Eimer, 1993;Falkenstein et al, 1999;Kok, 1986).…”

Copy number deletion burden is associated with cognitive, structural, and resting-state network differences in patients with schizophrenia

“…Reduced connectivity within the prefrontal cortex between the right DLPFC and the right iPFC in relation to increased deletion burden suggests deletions may be affecting local connectivity within the PFC and having a detrimental effect on the cognitive control network. The function of the right iPFC remains poorly understood, but appears to have a role in cognitive control, especially inhibition and reorienting [60][61][62]. Interestingly, functional connectivity between the right DLPFC region and a cluster predominantly in the right putamen was negatively correlated with total deletion burden.…”