Aspects Of Inhibitory Control Research Articles

Does impulsivity converge distinctively with inhibitory control? Disentangling the cold and hot aspects of inhibitory control

Trait impulsivity incorporates deficits in cognitive processes that can be viewed as resulting from deficiencies in executive functions, particularly inhibitory control. To better understand the relationship between impulsivity and inhibitory control, it is useful to divide inhibitory control into cognitive (cold) and emotional (hot) variants, mediated by differential neural networks. In this study, we aimed to examine impulsivity-related differences in inhibitory control in response to non-emotional versus emotional stimuli. We further examined impulsivity-related differences in the ability to maintain attention during a continuous and repetitive activity, based on the same distinction between cold and hot categories. To evaluate cold and hot variants of inhibition and attentional processes in relation to trait impulsivity, we used two types of go/no-go tasks, non-emotional and emotional. Trait impulsivity was assessed using the Barratt Impulsiveness Scale. Results showed that high-impulsivity individuals were less able to exert both cold and hot variants of inhibitory control. When cognitive performance involved emotional stimuli, high-impulsivity participants were less prone to lapses of attention and better able to maintain attention. In conclusion, trait impulsivity was manifested differently when emotional stimuli were involved, especially in terms of the attentional component. A division into affective and cognitive components of impulsivity is proposed.

The impulsive brain: Neural underpinnings of binge eating behavior in normal-weight adults

Converging evidence suggests that dysfunctional inhibitory control might be at the roots of overeating and binge eating disorder (BED). The majority of these results stems from studies on obese populations, however we hypothesized that potential prodromes might be evident also in non-clinical conditions, when binge eating episodes are present (without a diagnosis of BED) and a normal Body Mass Index is preserved.To explore this issue, brain activity of 42 normal weight individuals with and without binge eating episodes (21 binge eaters and 21 non-binge eaters, BE and non-BE respectively) was assessed by means of functional magnetic resonance imaging (fMRI) during response inhibition tasks. We adopted a food-modified version of a go/no-go (GNG) and stop signal task (SST): these tasks investigate different aspects of inhibitory control (action restraint and cancellation) that have been rarely studied in the same individuals but that are known to involve different neural networks. In addition, impulsivity traits were assessed with self-report instruments.Despite similar behavioral performances, the two groups differed in trait impulsivity and brain activity. The fMRI results revealed differential engagement of fronto-striatal regions between the groups during the tasks. The BE group, compared to non-BE, showed lower activation of the right middle frontal gyrus (MFG) and Putamen during the GNG task, and higher activation of the left MFG during the SST.These findings provide evidence of a dissociation of the neural underpinnings of action restraint and cancellation in impulsive individuals. Moreover, they add support to the hypothesis that impulsivity may be a possible hallmark of binge eating behavior (in the absence of weight or full-blown eating disorders) and yield new insights on the role of regions typically involved in response inhibition and selection as possible substrates of impulsive eating.

Inhibitory control and counterintuitive science and maths reasoning in adolescence.

Existing concepts can be a major barrier to learning new counterintuitive concepts that contradict pre-existing experience-based beliefs or misleading perceptual cues. When reasoning about counterintuitive concepts, inhibitory control is thought to enable the suppression of incorrect concepts. This study investigated the association between inhibitory control and counterintuitive science and maths reasoning in adolescents (N = 90, 11–15 years). Both response and semantic inhibition were associated with counterintuitive science and maths reasoning, when controlling for age, general cognitive ability, and performance in control science and maths trials. Better response inhibition was associated with longer reaction times in counterintuitive trials, while better semantic inhibition was associated with higher accuracy in counterintuitive trials. This novel finding suggests that different aspects of inhibitory control may offer unique contributions to counterintuitive reasoning during adolescence and provides further support for the hypothesis that inhibitory control plays a role in science and maths reasoning.

Differential roles of resistance to proactive interference and suppression of prepotent responses in overgeneral memory

Background and objectivesOvergeneral memory (OGM), difficulty in retrieving specific autobiographical memories, is a robust phenomenon related to the onset and course of depressive and posttraumatic stress disorders. Inhibitory mechanisms are theorized to underlie OGM; however, empirical support for this link is equivocal. The current study examines the differential roles of two aspects of inhibitory control in association with OGM: suppression of prepotent responses and resistance to proactive interference (PI). Only resistance to PI was expected to be negatively related to OGM, whereby individuals with greater ability to resist PI would have reduced OGM. MethodParticipants (n = 49) completed a self-report measure of depressive symptoms and engaged in two tasks aimed at assessing resistance to PI and suppression of prepotent responses. Participants also completed a task assessing overgeneral autobiographical memory. ResultsAs hypothesized, resistance to PI, but not suppression of prepotent responses negatively predicted OGM above and beyond the influence of depressive symptoms. LimitationsBecause a double dissociation was not examined, we cannot address the potential independence of the submechanisms of inhibitory control that we assessed. ConclusionsResults exemplify the differential associations of two components of inhibition and OGM, suggesting that resistance to PI, in particular, may contribute to the development and/or maintenance of OGM and associated depressive disorders. Directions for future research are discussed.

Cognitive Abilities and Mathematical Competencies at School Entry.

The aim of this study was to identify mathematical competencies in early childhood and cognitive correlates of those competencies in a prospective longitudinal sample of children (N=1292) in predominantly low-income and nonurban communities in the United States. General mental ability (IQ), processing speed, vocabulary, and the working memory, inhibitory control, and cognitive flexibility components of executive function (EF) were assessed when children were ages 4 and 5. Math ability was assessed prior to school entry using a norm-referenced assessment. Exploratory factor analysis indicated that items from the math assessment loaded onto factors representing conceptual and procedural skill. IQ, processing speed, vocabulary, and a unitary EF composite all related to both conceptual and procedural skill. When EF components were examined separately, however, only the inhibitory control aspect of EF was related to conceptual skill and only the working memory aspect of EF was related to procedural skill.

Do Children with Better Inhibitory Control Donate More? Differentiating between Early and Middle Childhood and Cool and Hot Inhibitory Control.

Inhibitory control may play an important part in prosocial behavior, such as donating behavior. However, it is not clear at what developmental stage inhibitory control becomes associated with donating behavior and which aspects of inhibitory control are related to donating behavior during development in early to middle childhood. The present study aimed to clarify these issues with two experiments. In Experiment 1, 103 3- to 5-year-old preschoolers completed cool (Stroop-like) and hot (delay of gratification) inhibitory control tasks and a donating task. The results indicated that there were no relationships between cool or hot inhibitory control and donating behavior in the whole group and each age group of the preschoolers. In Experiment 2, 140 elementary school children in Grades 2, 4, and 6 completed cool (Stroop-like) and hot (delay of gratification) inhibitory control tasks and a donating task. The results showed that inhibitory control was positively associated with donating behavior in the whole group. Cool and hot inhibitory control respectively predicted donating behavior in the second and sixth graders. Therefore, the present study reveals that donating behavior increasingly relies on specific inhibitory control, i.e., hot inhibitory control as children grow in middle childhood.

Dogs\u2019 reaction to inequity is affected by inhibitory control

Inequity aversion is thought to act as a mechanism to ensure cooperation and has been studied in many different species, consistently revealing inter-individual variation. Inhibitory control has been proposed to act as one factor responsible for this variation since individuals need to inhibit performing the required action and/or refuse rewards in order to exhibit inequity aversion. Here, we investigated if dogs’ sensitivity to inequity is affected by their capacity for inhibitory control, assessed in a test battery and questionnaire. Overall, dogs showing high compulsivity scores (i.e. repetitive behaviours independent of feedback) were more motivated to participate in the inequity task independent of the rewarding scheme. Dogs were more sensitive to inequity and individual contrast if they exhibited a slower decision speed in the inhibition tasks. Furthermore, less persistent and more impulsive dogs were more sensitive to reward inequity, potentially due to having a lower tolerance level for frustration. Results indicate that aspects of inhibitory control can explain the variation in dogs’ inequity response, highlighting one of the mechanisms underlying responses to inequity. Emphasising the importance to design paradigms, which allow us to disentangle capacities to recognise inequity from the inability to react to it due to poor inhibitory control abilities.

Electrophysiological indicators of inhibitory control deficits in depression

Ample evidence from behavioral and brain imaging studies suggests that inhibitory control is impaired in depression, though the precise nature of this impairment is unclear. The purpose of the present study was to examine potential deficits in three aspects of inhibitory control – conflict monitoring, conflict resolution, and overt behavioral inhibition – in the context of depressive symptoms. Depressed (n=15) and non-depressed (n=15) participants completed a stop-signal reaction time (SSRT) task while electroencephalography (EEG) data were recorded. EEG results indicate that depression impacts only the conflict resolution phase of inhibitory control, with higher levels of depressive and reflective pondering symptoms associated with poorer conflict resolution. Findings have clear implications for treatments of depression, many of which do not currently target the inhibitory control deficits present in this disorder.

Social exclusion impairs distractor suppression but not target enhancement in selective attention

Social exclusion has been thought to weaken one's ability to exert inhibitory control. Existing studies have primarily focused on the relationship between exclusion and behavioral inhibition, and have reported that exclusion impairs behavioral inhibition. However, whether exclusion also affects selective attention, another important aspect of inhibitory control, remains unknown. Therefore, the current study aimed to explore whether social exclusion impairs selective attention, and to specifically examine its effect on two hypothesized mechanisms of selective attention: target enhancement and distractor suppression. The Cyberball game was used to manipulate social exclusion. Participants then performed a visual search task while event-related potentials were recorded. In the visual search task, target and salient distractor were either both presented laterally or one was presented on the vertical midline and the other laterally. Results showed that social exclusion differentially affected target and distractor processing. While exclusion impaired distractor suppression, reflected as smaller distractor-positivity (Pd) amplitudes for the exclusion group compared to the inclusion group, it did not affect target enhancement, reflected as similar target-negativity (Nt) amplitudes for both the exclusion and inclusion groups. Together, these results extend our understanding of the relationship between exclusion and inhibitory control, and suggest that social exclusion affects selective attention in a more complex manner than previously thought.

MPQ Control (versus Impulsivity) and Need for Cognition – Relationship to behavioral inhibition and corresponding ERPs in a Go/No-Go task

Both, the MPQ Control (vs. Impulsivity) scale and the Need for Cognition (NFC) scale, refer to trait concepts encompassing reflective, goal-directed and controlled behavioral tendencies, with the former addressing more behavioral and the latter more cognitive aspects of control. However, research on their relationship with behavioral inhibition, especially with regard to electrophysiological aspects of inhibitory control is scarce. Therefore, in the present study, the trait scores of N=131 participants were analyzed with data from a Go/No-Go task and corresponding electrocortical measures of inhibition, the NoGo-N2 and NoGo-P3. Higher MPQ Control scores were associated with fewer false alarms, prolonged reaction times, and a delayed NoGo-N2. This suggests that MPQ Control is related to response inhibition and earlier stages of inhibition processing. There was no association between NFC and behavior, but higher scores were significantly associated with NoGo-N2 and even more strongly with NoGo-P3 latency. This suggests that NFC plays a role particularly in later stages of inhibition-related processing, but does not moderate the suppression of inappropriate and relatively automatic response tendencies in a basic response inhibition task. Future research should employ more complex tasks (e.g., impulsive choice/delay discounting tasks) to further clarify the relation of NFC to behavioral inhibition.

Neural and behavioral mechanisms of proactive and reactive inhibition.

Response inhibition is an important component of adaptive behavior. Substantial prior research has focused on reactive inhibition, which refers to the cessation of a motor response that is already in progress. More recently, a growing number of studies have begun to examine mechanisms underlying proactive inhibition, whereby preparatory processes result in a response being withheld before it is initiated. It has become apparent that proactive inhibition is an essential component of the overall ability to regulate behavior and has implications for the success of reactive inhibition. Moreover, successful inhibition relies on learning the meaning of specific environmental cues that signal when a behavioral response should be withheld. Proactive inhibitory control is mediated by stopping goals, which reflect the desired outcome of inhibition and include information about how and when inhibition should be implemented. However, little is known about the circuits and cellular processes that encode and represent features in the environment that indicate the necessity for proactive inhibition or how these representations are implemented in response inhibition. In this article, we will review the brain circuits and systems involved in implementing inhibitory control through both reactive and proactive mechanisms. We also comment on possible cellular mechanisms that may contribute to inhibitory control processes, noting that substantial further research is necessary in this regard. Furthermore, we will outline a number of ways in which the temporal dynamics underlying the generation of the proactive inhibitory signal may be particularly important for parsing out the neurobiological correlates that contribute to the learning processes underlying various aspects of inhibitory control.

Effects of Concomitant Stimulation of the GABAergic and Norepinephrine System on Inhibitory Control - A Study Using Transcutaneous Vagus Nerve Stimulation.

Inhibitory control processes are a central executive function. Several lines of evidence suggest that the GABAergic and the norepinephrine (NE) system modulate inhibitory control processes. Yet, the effects of conjoint increases in the GABAergic and NE system activity on inhibitory control have not been examined. We examine the conjoint effects of the GABA and NE system for inhibitory control. We used transcutaneous vagus nerve stimulation (tVNS), which has been shown to modulate both the GABAergic and NE system. We examine the effects of tVNS in two experimental paradigms examining different aspect of inhibitory control; i.e. a backward inhibition paradigm and a response inhibition paradigm modulating working memory load. There were no effects of tVNS on backward inhibition processes, but on response inhibition processes. Yet, these only emerged when working memory processes were needed to control response inhibition. Compared to a sham stimulation, tVNS induced better response inhibition performance (i.e. fewer false alarms). A concomitant modulation of the GABAergic and NE system, as induced by tVNS, affects inhibitory control processes, but only when working memory processes play an important role for inhibitory control. Even though both the GABAergic and the NE system are modulated by tVNS, the results suggest that the modulation of the NE system is most important for the emerging effects.

Dose-response relationship between intensity of exercise and cognitive performance in individuals with Down syndrome: a preliminary study.

Cognitive performance has been shown to be relevant to the early onset of Alzheimer's disease in individuals with Down syndrome. This study was aimed at investigating the dose-response relationship between acute exercise intensity and cognitive performance in this population. In the current study, we measured information processing speed and two aspects of executive function (i.e. attention shifting and inhibitory control). Participants were assigned to high-intensity exercise (i.e. 75-85% of predicted maximum heart rate) (N = 6), moderate-intensity exercise (i.e. 50-75% of predicted maximum heart rate) (N = 6) or attentional control (N = 6) groups. Two exercise groups walked on a treadmill using an incremental intensity walking protocol, and the attentional control group watched a video for 20 min. Measures of information processing speed and executive function were tested pre-intervention and post-intervention. Our results indicated that the performance in choice reaction time test was impaired in the high-intensity exercise, whereas improved performance was observed in the moderate-intensity exercise. However, moderate-intensity and high-intensity exercises were beneficial for inhibitory control aspect of executive function. Further, inconsistent with previous studies, a quadric trend was seen in information processing speed, and a liner trend was evident in inhibitory control. Future research is needed to examine with a larger sample size, and more physiological measures are necessary to explore the underlying mechanisms in the relationship between exercise intensity and cognitive performance in individuals with Down syndrome.

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs.

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance.

Of Huge Mice and Tiny Elephants: Exploring the Relationship Between Inhibitory Processes and Preschool Math Skills.

The cognitive mechanisms underpinning the well-established relationship between inhibitory control and early maths skills remain unclear. We hypothesized that a specific aspect of inhibitory control drives its association with distinct math skills in very young children: the ability to ignore stimulus dimensions that are in conflict with task-relevant representations. We used an Animal Size Stroop task in which 3- to 6-year-olds were required to ignore the physical size of animal pictures to compare their real-life dimensions. In Experiment 1 (N = 58), performance on this task correlated with standardized early mathematics achievement. In Experiment 2 (N = 48), performance on the Animal Size Stroop task related to the accuracy of magnitude comparison, specifically for trials on which the physical size of dot arrays was incongruent with their numerosity. This highlights a process-oriented relationship between interference control and resolving conflict between discrete and continuous quantity, and in turn calls for further detailed empirical investigations of whether, how and why inhibitory processes matter to emerging numerical cognition.

False belief understanding and "cool" inhibitory control in 3-and 4-years-old Italian children.

During preschool years, major developments occur in both executive function and theory of mind (ToM), and several studies have demonstrated a correlation between these processes. Research on the development of inhibitory control (IC) has distinguished between more cognitive, “cool” aspects of self-control, measured by conflict tasks, that require inhibiting an habitual response to generate an arbitrary one, and “hot,” affective aspects, such as affective decision making, measured by delay tasks, that require inhibition of a prepotent response. The aim of this study was to investigate the relations between 3- and 4-year-olds’ performance on a task measuring false belief understanding, the most widely used index of ToM in preschoolers, and three tasks measuring cognitive versus affective aspects of IC. To this end, we tested 101 Italian preschool children in four tasks: (a) the Unexpected Content False Belief task, (b) the Conflict task (a simplified version of the Day–Night Stroop task), (c) the Delay task, and (d) the Delay Choice task. Children’s receptive vocabulary was assessed by the Peabody Picture Vocabulary test. Children’s performance in the False Belief task was significantly related only to performance in the Conflict task, controlling for vocabulary and age. Importantly, children’s performance in the Conflict task did not significantly correlate with their performance in the Delay task or in the Delay Choice task, suggesting that these tasks measure different components of IC. The dissociation between the Conflict and the Delay tasks may indicate that monitoring and regulating a cool process (as flexible categorization) may involve different abilities than monitoring and regulating a hot process (not touching an available and highly attractive stimulus or choosing between a smaller immediate option and a larger delayed one). Moreover, our findings support the view that “cool” aspects of IC and ToM are interrelated, extending to an Italian sample of children previous findings on an association between self-control and ToM.

Left middle frontal gyrus response to inhibitory errors in children prospectively predicts early problem substance use

BackgroundA core vulnerability trait for substance use disorder (SUD) is behavioral disinhibition. Error processing is a central aspect of inhibitory control that determines adaptive adjustment of performance; yet it is a largely overlooked aspect of disinhibition as it relates to risk for SUD. We investigated whether differences in brain activation during both successful and failed inhibition predicts early problem substance use. MethodForty-five 9–12 year olds underwent a functional MRI scan during a go/no-go task. They were then followed over approximately 4 years, completing assessments of substance use. Externalizing behavior was measured at ages 3–8, 9–12 and 11–13. Participants with drug use or problem alcohol use by ages 13–16 (n=13; problem-user group) were individually matched by gender, age, and family history of alcoholism with non-substance-using children (n=13; non-user group). The remaining 19 participants provided an independent sample from which to generate unbiased regions-of-interest for hypothesis testing in the problem-user and non-user groups. ResultsNo differences were observed between groups in activation during correct inhibition compared with baseline. A significant difference arose in left middle frontal gyrus (LMFG) activation during failed inhibition compared with correct inhibition, with the problem-user group demonstrating blunted activation. The problem-user group also had more externalizing problems at ages 11–13. Logistic regression found that activation of LMFG significantly predicted group membership over and above externalizing problems. ConclusionsBlunted LMFG activation during performance errors may underlie problems adapting behavior appropriately, leading to undercontrolled behavior, early problem substance use and increased risk for SUD.

A developmental window into trade-offs in executive function: The case of task switching versus response inhibition in 6-year-olds

Good executive function has been linked to many positive outcomes in academic performance, health, and social competence. However, some aspects of executive function may interfere with other cognitive processes. Childhood provides a unique test case for investigating such cognitive trade-offs, given the dramatic failures and developments observed during this period. For example, most children categorically switch or perseverate when asked to switch between rules on a card-sorting task. To test potential trade-offs with the development of task switching abilities, we compared 6-year-olds who switched versus perseverated in a card-sorting task on two aspects of inhibitory control: response inhibition (via a stop signal task) and interference control (via a Simon task). Across two studies, switchers showed worse response inhibition than perseverators, consistent with the idea of cognitive trade-offs; however, switchers showed better interference control than perseverators, consistent with prior work documenting benefits associated with the development of executive function. This pattern of positive and negative associations may reflect aspects of working memory (active maintenance of current goals, and clearing of prior goals) that help children focus on a single task goal but hurt in situations with conflicting goals. Implications for understanding components of executive function and their relationships across development are discussed.

Effect of varenicline on aspects of inhibitory control in smokers

Varenicline, a partial agonist at α4β2 nicotinic receptors (nAChRs) aids smoking cessation by reducing craving. Successful quitting may be associated with greater inhibitory control but the effectiveness of varenicline in this regard is unknown. This study aimed to investigate the effect of varenicline on aspects of inhibitory control in smokers. A double-blind, placebo-controlled study investigating the effect of varenicline 1 mg (or matched placebo) in satiated and abstinent smokers. Tests included Rapid Visual Information Processing (RVIP), Stop-Signal (SS), Prospective Memory (PM) and the Cambridge Gambling Task (CGT). Smoking enhanced RVIP accuracy and latency to respond. Varenicline did not alter RVIP performance, nor the effect of smoking, suggesting that these effects were unrelated to α4β2 nAChRs. Smoking increased the number of errors during SS and increased the stop latency, indicating that smoking decreased inhibitory control. Varenicline partially mimicked this effect of smoking but also reduced the smoking-induced increase, indicating a role for α4β2 nAChRs. Likewise, smoking increased the number of points bet following a win during CGT and varenicline blocked this effect. There was no effect of smoking or varenicline on PM target detection per se. However, smoking protected the target detection rate in the ongoing task when a concurrent intention was introduced. Varenicline improved response speed in both satiated and abstinent smokers. Some aspects of inhibitory control may be mediated by α4β2-related mechanisms and blockade of smoking-induced disinhibition may contribute towards the action of varenicline as an aid to smoking cessation.

Genetic variations in dopamine and inhibitory control: Lack of influence on action restraint

Failures of inhibitory control can severely affect everyday life in healthy individuals and represent a common feature of many neuropsychiatric conditions, particularly disorders with dopaminergic disturbances implicated. This study's aim was to examine the interacting influences of three common and functional gene variants that influence dopaminergic pathways on an aspect of inhibitory control (action restraint). Three hundred and twenty two healthy adults were selected from an international consortium linked to Brain Research and Integrative Neuroscience (BRAINnet). DNA was extracted from cheek swab samples and participants were genotyped for the Val158Met single nucleotide polymorphism on COMT (rs 4680), C957T on DRD2 (rs 6277) and the 40bp variable number of tandem repeat on the DAT1 (SLC6A3, 10/10 vs 9+). Response inhibition was measured using a computerised Go/No-Go task. Main effects and interactions between genotypes were explored. We did not observe a genotype effect on fundamental measures of response inhibition, i.e. reaction time (RT) and commission errors. RT variability was significantly increased in DRD2 C957T heterozygotes. In conclusion, this large, non-clinical study reveals that the selected genetic polymorphisms regulating dopamine (COMT, DRD2 and DAT1) do not influence one aspect of response inhibition, action restraint, as measured by the Go/No-Go task, reinforcing the neuropharmacological dissociation between stop-signal and Go/No-Go tasks. Genetic variation in striatal dopamine may, however, contribute to intraindividual RT variability.