Measures Of Response Inhibition Research Articles

Effects of bilateral tDCS over DLPFC on response inhibition, craving, and brain functional connectivity in Internet gaming disorder: Arandomized, double-blind, sham-controlled trial with fMRI.

Impaired inhibitory control accompanied by enhanced craving is hallmark of addiction. This study investigated the effects of transcranial direct current stimulation (tDCS) on response inhibition and craving in Internet gaming disorder (IGD). We examined the brain changes after tDCS and their correlation with clinical variables. Twenty-four males with IGD were allocated randomly to an active or sham tDCS group, and data from 22 participants were included for analysis. Participants self-administered bilateral tDCS over the dorsolateral prefrontal cortex (DLPFC) for 10 sessions. Stop-signal tasks were conducted to measure response inhibition and participants were asked about their cravings for Internet gaming at baseline and post-tDCS. Functional magnetic resonance imaging data were collected at pre- and post-tDCS, and group differences in resting-state functional connectivity (rsFC) changes from the bilateral DLPFC and nucleus accumbens were examined. We explored the relationship between changes in the rsFC and behavioral variables in the active tDCS group. A significant group-by-time interaction was observed in response inhibition. After tDCS, only the active group showed a decrease in the stop-signal reaction time (SSRT). Although craving decreased, there were no significant group-by-time interactions or group main effects. The anterior cingulate cortex (ACC) showed group differences in post- versus pre-tDCS rsFC from the right DLPFC. The rsFC between the ACC and left middle frontal gyrus was negatively correlated with the SSRT. Our study provides preliminary evidence that bilateral tDCS over the DLPFC improves inhibitory control and could serve as a therapeutic approach for IGD.

A proof-of-concept study testing the factor structure of the Stop Signal Task: overlap with substance use and mental health symptoms

ABSTRACT Background: Research utilizing experimental tasks usually does not report estimates of internal reliability of measurement. However, modern measurement theories conceptualize reliability as sample dependent indicating that reliability should be empirically demonstrated in the samples used to make inferences. Objectives: Test whether confirmatory factor analytic (CFA) estimates of reliability can be applied to a commonly used task measuring response inhibition (the Stop Signal Task) to predict substance use (alcohol and cannabis) and mental health symptoms. Methods: Thirty-seven participants between the ages of 18–20 (72% female; 16% Asian, 3% Native American, 11% Black or African American, 59% White; 32% Latino/a/x) were recruited via social media advertisement and attended a laboratory visit. The Stop Signal Reaction Time (SSRT) was calculated as the outcome for three experimental blocks and used as indicators in a CFA. Results: CFA suggests the task yields reliable scores; factor loadings were statistically significant (p < .05) and substantial (standardized loadings ranged from .74 to .94). However, reliability increased across experimental blocks and error was non-trivial (ranging from 50% to 12% of the variance). The inhibition factor predicted higher maximum number of drinks consumed (β = .37, p < .05), higher frequency of cannabis use (β = .39, p < .05), and more cannabis use occasions within using days (β = .40, p < .05), as well as facets of mental health (anxious/depression, attention, and anxiety problems; all p’s < .05). Conclusion: Results support the utility of CFA to test for reliability of measurement, with the ability to inhibit dominant responses serving as a transdiagnostic correlate of substance use and mental health problems.

A differential impact of action–effect temporal contiguity on different measures of response inhibition in the Go\\No-Go and Stop-signal paradigms

Response inhibition refers to suppressing a prepotent motor response and is often studied and discussed as an act of cognitive control. Much less attention was given to the potential contribution of motor control processes to response inhibition. Accumulated empirical findings show that a perceptual effect temporally contiguous with a response improves motor control performance. In the current study, we followed this work by manipulating action–effect temporal contiguity to enhance motor performance and investigated its impact on response selection and inhibition. In two experiments, we integrated a Go/No-Go (GNGT; Experiment 1) and a Stop-signal (SST; Experiment 2) task with the Effect–Motivation task, previously used to capture the facilitating impact of action–effect temporal contiguity on response times (RTs). Replicating previous findings, RTs were shorter following temporally contiguous compared to Lagged action–effect in Go trials in both the GNGT (Experiment 1) and SST (Experiment 2). Notably, an Immediate action–effect improved response inhibition in the GNGT (Experiment 1) but did not modulate Stop-signal reaction time (SSRT) in the SST (Experiment 2). Unexpectedly, the error rate on Go trials was higher in the Immediate effect condition in Experiment 2. We interpret the findings to suggest that an action’s (Immediate) perceptual effect may promote response inhibition performance by enhancing selective association between the Go stimuli and the Go response and not by improving cognitive control ability. The findings also imply that an Immediate action–effect may hamper action control (e.g., by increasing general readiness to respond), at least when action control does not benefit from automatic stimulus–response association.

NIH Toolbox performance of persons with Parkinson's disease according to GBA1 and STN-DBS status.

Mutations in the glucocerebrosidase (GBA1) gene and subthalamic nucleus deep brain stimulation (STN-DBS) are independently associated with cognitive dysfunction in persons with Parkinson's disease (PwP). We hypothesized that PwP with both GBA1 mutations and STN-DBS are at greater risk of cognitive dysfunction than PwP with only GBA1 mutations or STN-DBS, or neither. In this study, we determined the pattern of cognitive dysfunction in PwP based on GBA1 mutation status and STN-DBS treatment. PwP who are GBA1 mutation carriers with or without DBS (GBA1+DBS+, GBA1+DBS-), and noncarriers with or without DBS (GBA1-DBS+, GBA1-DBS-) were included. Using the NIH Toolbox, cross-sectional differences in response inhibition, processing speed, and episodic memory were compared using analysis of variance with adjustment for relevant covariates. Data were available for 9 GBA1+DBS+, 14 GBA1+DBS-, 17 GBA1-DBS+, and 26 GBA1-DBS- PwP. In this cross-sectional study, after adjusting for covariates, we found that performance on the Flanker test (measure of response inhibition) was lower in GBA1+DBS+ PwP compared with GBA1-DBS+ PwP (P = 0.030). PwP who carry GBA1 mutations and have STN-DBS have greater impaired response inhibition compared with PwP with STN-DBS but without GBA1 mutations. Longitudinal data, including preoperative scores, are required to definitively determine whether GBA1 mutation carriers respond differently to STN-DBS, particularly in the domain of response inhibition.

A hybrid approach to dynamic cognitive psychometrics : Dynamic cognitive psychometrics.

Dynamic cognitive psychometrics measures mental capacities based on the way behavior unfolds over time. It does so using models of psychological processes whose validity is grounded in research from experimental psychology and the neurosciences. However, these models can sometimes have undesirable measurement properties. We propose a "hybrid" modeling approach that achieves good measurement by blending process-based and descriptive components. We demonstrate the utility of this approach in the stop-signal paradigm, in which participants make a series of speeded choices, but occasionally are required to withhold their response when a "stop signal" occurs. The stop-signal paradigm is widely used to measure response inhibition based on a modeling framework that assumes a race between processes triggered by the choice and the stop stimuli. However, the key index of inhibition, the latency of the stop process (i.e., stop-signal reaction time), is not directly observable, and is poorly estimated when the choice and the stop runners are both modeled by psychologically realistic evidence-accumulation processes. We show that using a descriptive account of the stop process, while retaining a realistic account of the choice process, simultaneously enables good measurement of both stop-signal reaction time and the psychological factors that determine choice behavior. We show that this approach, when combined with hierarchical Bayesian estimation, is effective even in a complex choice task that requires participants to perform only a relatively modest number of test trials.

43 Chronic Neurobehavioral and Cognitive Symptoms in Combat Deployed Military Service Personnel With and Without History of Blast-Related Mild Traumatic Brain Injury

Objective:Investigate the relationship of chronic neurobehavioral and cognitive symptoms in military personnel with history of blast-related mild TBI and compare to a well-matched group of combat-deployed controls.Participants and Methods:274 participants (mean age=34 years; mean education=14.75 years; 91.2% male) enrolled in the EVOLVE longitudinal study of combat-deployed military personnel were subdivided into those with history of blast TBI (n=165) and controls without history of blast exposure and TBI (n=109). As part of a larger study, we conducted a sub-analysis of 5-year follow up data. We focused on group differences (Mann-Whitney U) and correlational relationships between self-report neurobehavioral symptoms via the Frontal Systems Behavior Scale (FrSBE) and cognitive performances on measures of attention, working memory, processing speed, and executive functioning including D-KEFS Color Word Interference (CWI), Trailmaking A and B, and the Conners Continuous Performance Test (CPT).Results:The Blast TBI group reported higher levels of neurobehavioral symptoms on the FrSBE (p&lt;.001), including domains of apathy (p&lt;.001), disinhibition (p&lt;.001), and executive dysfunction (p&lt;.001), compared to Controls. On cognitive measures, group differences were observed on CWI Inhibition/Switching (p=.008), Trails B time (p=.010), and CPT commission errors (p=.014), such that the Blast TBI group performed worse than Controls. No significant group differences were observed for CPT omission errors or CPT hit rate (p’s&gt;.05). After adjustment for multiple comparisons, greater FrSBE apathy correlated with slower performance on Trails A for Blast TBI (r=0.22, p=.014) but not Controls. Apathy endorsement was not significantly related to CPT omission errors for either group (p’s&gt;.05). Higher endorsement of disinhibition symptoms was associated with worse performance on CWI Inhibition (Blast TBI: r=-0.19, p=.036; Controls: r=-0.28, p=.012) and Inhibition/Switching (Blast TBI: r=-0.23, p=.010; Controls: r=-0.29, p=.010) conditions for both groups, whereas only the Blast TBI group showed significant relationships between disinhibition symptoms and Trails B-A time (r=0.20, p=.025) and CPT commission errors (r=.18, p=.038). Higher endorsement of executive dysfunction correlated with poorer performance for Trails B-A for both groups (Blast TBI: r=.24, p=.009; Controls: r=.24, p=.030).Conclusions:Our findings reveal that at 5-year follow up, military personnel with history of blast-related mild TBI reported significantly greater neurobehavioral symptoms and performed lower on standardized measures of executive functioning, relative to combat-deployed controls without TBI or blast exposure. Significant relationships between neurobehavioral symptoms and cognitive performance were present in both groups. However, these relationships were more pronounced in the Blast TBI group, including greater apathy associated with slower visual tracking as well as greater endorsement of disinhibition associated with set-switching. Objective measures of response inhibition were related to disinhibition endorsement for both groups, though impulsive errors were more pronounced for the Blast TBI group. Our results suggest chronic cognitive and neurobehavioral symptoms are present in military personnel with history of blast TBI exposure, and also discrepant from a well-matched control group of combat deployed military personnel. Future studies of this population should explore models to predict cognitive performance from neurobehavioral symptoms in military personnel, as this could inform treatment approaches for those at greatest risk of cognitive change.

80 Longitudinal Development of Response Inhibition in Adolescence and Young Adulthood and Associations with Gray Matter Architecture

Objective:The present study explored how individual differences and development of gray matter architecture in inferior frontal gyri (IFG), anterior cingulate (ACC), and inferior parietal lobe (IPL) relate to development of response inhibition as measured by both the Stop Signal Task (SST) and the Go/No-Go (GNG) task in a longitudinal sample of healthy adolescents and young adults. Reliability of behavioral and neural measures was also explored.Participants and Methods:A total of 145 individuals contributed data from the second through fifth timepoints of an accelerated longitudinal study focused on adolescent brain and behavioral development at the University of Minnesota. At baseline, participants were 9 to 23 years of age and were typically-developing. Assessment waves were spaced approximately 2 years apart. Behavioral measures of response inhibition collected at each assessment included GNG Commission Errors (CE) and the SST Stop Signal Reaction Time (SSRT). Structural T1 MRI scans were collected on a Siemens 3 T Tim Trio and processed with the longitudinal Freesurfer 6.0 pipeline to yield cortical thickness (CT) and surface area values. Regions of interest based on the Desikan-Killiany-Tourville atlas included IFG regions (pars opercularis (PO) and pars triangularis (PT)), ACC and IPL. The cuneus and global brain measures were evaluated as control regions. Retest stability of all measures was calculated using the psych package in R. Mixed linear effects modeling using the lme4 R package identified whether age-based trajectories for SSRTs and GNG CEs best fit linear, quadratic, or inverse curve. Then, disaggregated between- and within-subjects effects of regional cortical architecture measures were added to longitudinal behavioral models to identify individual differences and developmental effects, respectively.Results:Both response inhibition metrics demonstrated fair reliability and were best fit by an inverse age trajectory. Neural measures demonstrated excellent retest stability (all ICCs &gt; 0.834). Age-based analyses of regional CT identified heterogeneous patterns of development, including linear trajectories for ACC and inverse age trajectories for bilateral PT. Individuals with thinner left PO showed worse performance on both response inhibition tasks. SSRTs were related to individual differences in right PO thickness and surface area. A developmental pattern was observed for right PT cortical thickness, where thinning over time was related to better GNG performance. Lower surface area of the right PT was related to worse GNG performance. No individual differences or developmental patterns were observed for the ACC, IPL, cuneus, or global metrics.Conclusions:This study examined the adolescent development of response inhibition and its association with cortical architecture in the IFG, ACC and IPL. Separate response inhibition tasks demonstrated similar developmental patterns with steepest improvements in early adolescence and relationships with left PO thickness, but each measure had unique relationships with other IFG regions. This study indicates that a region of the IFG, the par opercularis, relates to both individual difference and developmental change in response inhibition. These patterns suggest brain-behavior association that could be further explored in functional imaging studies and that may index, in vulnerable individuals, risk for psychopathology.

Executive functions in children with specific learning disorders: Shedding light on a complex profile through teleassessment

Executive Functions (EFs) are high-order cognitive processes relevant to learning and adaptation and frequently impaired in children with specific learning disorders (SLDs). This study aimed to investigate EFs in children with SLD and explore the role of specific EF-related subprocesses, such as stimuli processing and processing speed. Fifty-seven SLD and 114 typically developing (TD) children, matched for gender and age, completed four tasks measuring response inhibition, interference control, shifting, and updating on a web-based teleassessment platform. The results show that SLD children performed lower in all EF tasks than TD children, regardless of stimulus type and condition. Mediation analyses suggested that differences between the SLD and TD groups are mediated by EF-related subprocesses, offering an interpretative model of EF deficits in children with SLD.

Self‐regulatory control processes in youths: A temporal network analysis approach

AbstractObjectiveThis study aimed to better understand the temporal interrelationships among self‐control, response inhibition, and anger (i.e., momentary state and rumination) on both the within‐ and between‐person levels in male adolescents.MethodWe applied temporal network analyses among 62 male adolescents with a wide range of behavioral difficulties. Self‐control, momentary anger, and anger rumination were mapped by self‐report measures, whereas we measured response inhibition through an ambulatory Go/No‐go task (two measures a day—morning and afternoon—over a 9‐day period).ResultsTemporal network analysis, at the within‐person level, revealed that morning measures of response inhibition, anger rumination, and self‐control were related to the corresponding measure in the afternoon. More efficient response inhibition in the morning was associated with higher self‐control in the afternoon. Higher anger rumination in the morning led to higher momentary anger in the afternoon. In a concurrent within‐person network, higher momentary anger was reciprocally associated with lower self‐control. At the between‐person level, higher momentary anger was correlated to higher anger rumination, lower response inhibition, and lower self‐control.DiscussionThis study provides insight into the dynamic interactions among self‐control, response inhibition, and anger (momentary state and rumination) in male adolescents, advancing the understanding of self‐regulatory control functioning.

ADHD-related sex differences in frontal lobe white matter microstructure and associations with response control under conditions of varying cognitive load and motivational contingencies.

Children with attention-deficit/hyperactivity disorder (ADHD) demonstrate reduced response inhibition, increased response time variability, and atypical frontal lobe white matter microstructure with emerging evidence of sex differences. This study aims to examine whether frontal lobe white matter microstructure is differentially impacted in ADHD by sex and whether this relates to Go/No-Go (GNG) task performance. Diffusion tensor imaging (DTI) from 187 children (8-12 years), including ADHD (n = 94) and typically developing controls (TD; n = 93). Participants completed three GNG tasks with varying cognitive demands and incentives (standard, cognitive, and motivational). Fractional anisotropy (FA) was examined as an index of white matter microstructure within bilateral frontal lobe regions of interest. Children with ADHD showed reduced FA in primary motor (M1) and supplementary motor area (SMA) regardless of sex. Sex-based dissociation for the effect of diagnosis was observed in medial orbitofrontal cortex (mOFC), with higher FA in girls with ADHD and lower FA in boys with ADHD. Both diagnosis and sex contributed to performance on measures of response inhibition and reaction time (RT) variability, with all children with ADHD demonstrating poorer performance on all GNG tasks, but boys with ADHD demonstrating more impulsivity on standard and motivational behavioral paradigms compared to girls with ADHD. Analyses revealed associations between reduced FA in M1, SMA, and mOFC and increased response inhibition and RT variability with some sex-based differences. These findings provide novel insights regarding the brain basis of ADHD and associated impairments in response inhibition and RT variability, and contribute to our understanding of sexual dimorphic behavioral outcomes.

Inflamed but not impulsive: Acute inflammatory cytokine response does not impact prepotent response inhibition

BackgroundPrior evidence has linked inflammation with impulsivity, but most of this evidence is cross-sectional. In this study, we provoked an acute inflammatory cytokine response to see whether it lowered prepotent response inhibition on three cognitive tasks. MethodThis study features secondary analyses from a randomized crossover trial in which 171 postmenopausal breast cancer survivors (Stage I-IIIA) each received a typhoid capsular polysaccharide vaccination and a saline placebo injection in a random sequence at two separate visits at least one month apart. Participants completed the Stroop Color-Discrepant Task, the 2-back, and the Conners Continuous Performance Test (CPT) on the computer between 5 and 7 h after the injections. They had their blood drawn once before and repeatedly after the injection to measure interleukin-1 receptor antagonist and interleukin-6 responses. ResultsWomen committed marginally fewer errors on the Stroop color-discrepant trials after the typhoid vaccine (M = 0.36, SE = 0.08), compared to placebo (M = 0.54, SE = 0.09, p = .076). Injection type did not predict 2-back accuracy (p = .80) or CPT commission errors (p = .47). Inflammatory cytokine responses were also unrelated to the outcomes of interest (ps>.16). ConclusionWe found no evidence that an acute inflammatory cytokine response provokes response disinhibition – an important facet of impulsivity. In fact, our only marginally non-significant result suggested that women were better able to inhibit their prepotent responses on the Stroop after receiving the typhoid vaccine, compared to placebo. Further experimental tests of the acute inflammatory cytokine response's effect on other aspects of impulsivity are warranted. LimitationsThe sample was female, primarily White, highly educated cancer survivors, and recruitment was not premised on impulsive traits or diagnosis with an impulsive-related disorder. Also, there are many facets of impulsivity, and this study only measured response inhibition.

Prefrontal oxygenation varies as a function of response inhibition performance in healthy participants but not in youth with non-suicidal self-injury.

Non-suicidal self-injury (NSSI), a highly prevalent symptom in adolescence, has been associated with impulsivity. Behavioral measures of response inhibition in combination with the recording of brain activity potentially improve the understanding of the etiology of the behavior. We therefore investigated prefrontal cortex (PFC) oxygenation during a response inhibition task using functional near-infrared spectroscopy (fNIRS) in n=152 adolescents with NSSI and n=47 healthy controls. We compared groups regarding behavioral performance and PFC oxygenation and tested whether the association between task performance and PFC oxygenation differed between groups. PFC oxygenation was slightly higher in adolescents with NSSI than in controls. Further, there was evidence for a group by performance interaction: In healthy controls, higher oxygenated hemoglobin was associated with better task performance, which was not the case in the NSSI group. We did not find evidence of associations between PFC oxygenation and clinical measures. Our study provides preliminary evidence of altered brain functional correlates of response inhibition in adolescents with NSSI potentially reflecting deficient top-down regulation of limbic regions through prefrontal regions. Due to methodological limitations of the current study, findings must be interpreted with caution and future studies should optimize task designs for fNIRS processing.

Posterior cingulate cortex spontaneous activity associated with motor response inhibition in patients with obsessive-compulsive disorder: A resting-state fMRI study

Recent evidence suggests that broad brain regions, not limited to the fronto-striato-thalamo-cortical circuit, play an important role in motor response inhibition. However, it is still unclear which specific key brain region is responsible for impaired motor response inhibition observed in obsessive-compulsive disorder (OCD).We calculated the fractional amplitude of low-frequency fluctuations (fALFF) and measured response inhibition ability using the stop-signal task in 41 medication-free patients with OCD and 49 healthy control (HC) participants. We explored the brain region that shows different association between the fALFF and the ability of motor response inhibition.Significant differences in fALFF associated with the ability of motor response inhibition were identified in dorsal posterior cingulate cortex (PCC). There was a positive correlation between increased fALFF in the dorsal PCC and impaired motor response inhibition in OCD. In the HC group, there was a negative correlation between the two variables.Our results suggest that the magnitude of resting-state blood oxygen level-dependent oscillation of the dorsal PCC is a key brain region for the underlying mechanisms of impaired motor response inhibition in OCD. Future studies should examine whether this characteristic of dorsal PCC affects other large-scale networks responsible for motor response inhibition of OCD.

Investigating Intra-Individual Networks of Response Inhibition and Interference Resolution using 7T MRI

Response inhibition and interference resolution are often considered subcomponents of an overarching inhibition system that utilizes the so-called cortico-basal-ganglia loop. Up until now, most previous functional magnetic resonance imaging (fMRI) literature has compared the two using between-subject designs, pooling data in the form of a meta-analysis or comparing different groups. Here, we investigate the overlap of activation patterns underlying response inhibition and interference resolution on a within-subject level, using ultra-high field MRI. In this model-based study, we furthered the functional analysis with cognitive modelling techniques to provide a more in-depth understanding of behaviour. We applied the stop-signal task and multi-source interference task to measure response inhibition and interference resolution, respectively. Our results lead us to conclude that these constructs are rooted in anatomically distinct brain areas and provide little evidence for spatial overlap. Across the two tasks, common BOLD responses were observed in the inferior frontal gyrus and anterior insula. Interference resolution relied more heavily on subcortical components, specifically nodes of the commonly referred to indirect and hyperdirect pathways, as well as the anterior cingulate cortex, and pre-supplementary motor area. Our data indicated that orbitofrontal cortex activation is specific to response inhibition. Our model-based approach provided evidence for the dissimilarity in behavioural dynamics between the two tasks. The current work exemplifies the importance of reducing inter-individual variance when comparing network patterns and the value of UHF-MRI for high resolution functional mapping.

Impairments in Emotion Recognition and Positive Emotion Regulation Predict Social Difficulties in Adolescent With ADHD.

Emotional dysregulation, poor emotion recognition and impaired response inhibition have been highlighted as potential contributors to social difficulties in adolescents with attention-deficit/hyperactivity disorder (ADHD). It is currently unknown how these areas of impairment relate to one another; therefore, this study aims to identify the areas of emotion regulation which are associated with social difficulties in adolescents with ADHD, and determine whether emotion regulation mediates the relationship between deficits in response inhibition and emotion recognition, and social functioning, in this cohort. Thirty Australian adolescents (Male = 21) with ADHD completed measures of response inhibition, emotion recognition, and emotion regulation. Positive emotion regulation was significantly associated with social difficulties. Although emotion recognition significantly predicted social difficulties, there was no relationship between emotion recognition and emotion regulation in this sample, ruling out emotion regulation as a mediator of emotion recognition and social difficulties. Whilst response inhibition was significantly correlated with positive emotion regulation, positive emotion regulation did not mediate the relationship between response inhibition and social difficulties. Difficulties recognising and regulating emotions appear to independently contribute to social difficulties in adolescents with ADHD. Interventions to increase emotional understanding and developing strategies to down-regulate positive emotions may be beneficial.

Exploring stop signal reaction time over two sessions of the anticipatory response inhibition task

Various behavioural tasks measure response inhibition encompassing the ability to cancel unwanted actions, evaluated via stop signal reaction time (SSRT). It is unclear whether SSRT is an unchangeable inherent measure of inhibitory network integrity or whether it can improve with repetition. The current study explored if and how SSRT changed over two sessions for the Anticipatory Response Inhibition Task (ARIT), and how this compared with the Stop Signal Task (SST). Forty-four participants repeated the ARIT and SST over two sessions. SSRT and its constituent measures (Go trial reaction time, stop signal delay) were calculated. SSRT reflecting non-selective response inhibition was consistent between sessions in the ARIT and SST (both p > 0.293). Reaction time and stop signal delay also remained stable across sessions in the ARIT (all p > 0.063), whereas in the SST, reaction time (p = 0.013) and stop signal delay (p = 0.009) increased. SSRT reflecting behaviourally selective stopping on the ARIT improved (p < 0.001) over two sessions, which was underpinned by changes to reaction time (p < 0.001) and stop signal delay (p < 0.001). Overall, the maximal efficiency of non-selective inhibition remained stable across two sessions in the ARIT. Results of the SST confirmed that non-selective inhibition can, however, be affected by more than inhibitory network integrity. Behaviourally selective stopping on the ARIT changed across sessions, suggesting the sequential neural process captured by the SSRT occurred more quickly in session two. These findings have implications for future studies that necessitate behavioural measures over multiple sessions.

Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder: Shared or Unique Neurocognitive Profiles?

Attention-deficit/hyperactivity (ADHD) and autism spectrum (ASD) disorders are commonly co-occurring conditions characterized by neurocognitive impairments. Few studies have directly compared neurocognitive profiles in ADHD and ASD and fewer still have controlled for comorbidity of ADHD and ASD. All direct comparisons have been in clinic samples, leaving the question of generalizability of results unaddressed. We compared neurocognitive performance in clinically ascertained ASD (n = 261) and ADHD (n = 423) cases and controls (n = 162), 6.0–17.9 years of age. We also compared ASD (n = 190) and ADHD (n = 926) cases ascertained in the community with controls (n = 14,842) of similar age. Using the stop-signal task (SST), we measured response inhibition (stop-signal reaction time–SSRT), sustained attention (defined as reaction time variability–RTV), and reaction time (RT). We controlled for comorbidity using ADHD and ASD trait scores and categorically-defined ADHD. Compared with controls, both clinic ADHD and ASD had significantly longer SSRT and RTV than controls and did not differ from each other. ADHD traits accounted for neurocognitive impairment in ASD, but not vice versa. There were no group differences for RT. Similar patterns of neurocognitive impairment were observed in the community sample. In the largest direct comparison of ADHD and ASD to date, we found impaired response inhibition and sustained attention in both disorders. However, neurocognitive impairment in ASD was almost completely accounted for by comorbid ADHD. Results generalized in the community sample indicating that referral bias alone did not drive results. Response inhibition and sustained attention likely play a role in ADHD and ASD.

Web-Based Independent Versus Laboratory-Based Stop-Signal Task Performance: Within-Subjects Counterbalanced Comparison Study.

BackgroundConsidered a facet of behavioral impulsivity, response inhibition facilitates adaptive and goal-directed behavior. It is often assessed using the Stop-Signal Task (SST), which is presented on stand-alone computers under controlled laboratory conditions. Sample size may consequently be a function of cost or time and sample diversity constrained to those willing or able to attend the laboratory. Statistical power and generalizability of results might, in turn, be impacted. Such limitations may potentially be overcome via the implementation of web-based testing.ObjectiveThe aim of this study was to investigate if there were differences between variables derived from a web-based SST when it was undertaken independently—that is, outside the laboratory, on any computer, and in the absence of researchers—versus when it was performed under laboratory conditions.MethodsWe programmed a web-based SST in HTML and JavaScript and employed a counterbalanced design. A total of 166 individuals (mean age 19.72, SD 1.85, range 18-36 years; 146/166, 88% female) were recruited. Of them, 79 undertook the independent task prior to visiting the laboratory and 78 completed the independent task following their laboratory visit. The average time between SST testing was 3.72 (SD 2.86) days. Dependent samples and Bayesian paired samples t tests were used to examine differences between laboratory-based and independent SST variables. Correlational analyses were conducted on stop-signal reaction times (SSRT).ResultsAfter exclusions, 123 participants (mean age 19.73, SD 1.97 years) completed the SST both in the laboratory and independently. While participants were less accurate on go trials and exhibited reduced inhibitory control when undertaking the independent—compared to the laboratory-based—SST, there was a positive association between the SSRT of each condition (r=.48; P<.001; 95% CI 0.33-0.61).ConclusionsFindings suggest a web-based SST, which participants undertake on any computer, at any location, and in the absence of the researcher, is a suitable measure of response inhibition.

The neural correlates of inhibitory control in 10-month-old infants: A functional near-infrared spectroscopy study

Inhibitory control, a core executive function, emerges in infancy and develops rapidly across childhood. Methodological limitations have meant that studies investigating the neural correlates underlying inhibitory control in infancy are rare. Employing functional near-infrared spectroscopy alongside a novel touchscreen task that measures response inhibition, this study aimed to uncover the neural underpinnings of inhibitory control in 10-month-old infants (N = 135). We found that when inhibition was required, the right prefrontal and parietal cortices were more activated than when there was no inhibitory demand. This demonstrates that inhibitory control in infants as young as 10 months of age is supported by similar brain areas as in older children and adults. With this study we have lowered the age-boundary for localising the neural substrates of response inhibition to the first year of life.

A method to assess response inhibition during a balance recovery step

BackgroundCorrelations between falls and individual differences in inhibitory control, suggest the ability to suppress automatic, but unwanted, action is important in fall prevention. Response inhibition has been a topic of considerable interest in the cognitive neuroscience community for many decades, bringing a wealth of techniques that could potentially inform assessment of reactive balance. For example, the stop signal task is a popular method to quantify inhibitory control ability. Research questionCan we apply the stop signal task to measure response inhibition in a balance recovery task? MethodsTwenty healthy, young adults completed a novel reactive balance test that required occasional suppression of a balance recovery step. Participants were released from a supported lean (‘Go’ cue) requiring them to quickly step forward to regain balance. On some trials, a tone (‘Stop’ cue) instructed participants to suppress a step and relax into a harness. Step trials were more frequent (80%) than stop trials (20%) to bias a rapid stepping response. The stop tone was presented at various delays following cable release, to manipulate task difficulty (i.e., longer delays make step suppression difficult). Individual differences in inhibitory control were determined using lift off times from force plates, and by contrasting muscle activation in failed compared to successful stop trials. ResultsMost participants were able to successfully suppress a balance recovery step on occasion, allowing for accurate estimation of individual differences in inhibitory control. The successful suppression of a balance recovery step was more likely in the group (n = 10) where shorter stop signal delays were used (i.e., the task was easier). SignificanceWhile balance assessments often stress reflexive action, there is a need for methods that evaluate response inhibition. The present study leveraged a well-established cognitive test of inhibitory control to develop a method to quantify stopping ability in a reactive balance context.