Associations between trait impulsivity and prepotent response inhibition

The antisaccadic paradigm: A complementary neuropsychological tool in basal ganglia disorders

This review explores the role of the antisaccadic task in understanding inhibitory mechanisms in basal ganglia disorders. It conducts a comparative analysis of saccadic profiles in conditions such as Parkinson's disease, Tourette syndrome, obsessive-compulsive disorder, Huntington's disease, and dystonia, revealing distinct patterns and proposing mechanisms for impaired performance. The primary focus is on two inhibitory mechanisms: global, pre-emptive inhibition responsible for suppressing prepotent responses, and slower, selective response inhibition. The antisaccadic task demonstrates practicality in clinical applications, aiding in differential diagnoses, treatment monitoring and reflecting gait control. To further enhance its differential diagnostic value, future directions should address issues such as the standardization of eye-tracking protocol and the integration of eye-tracking data with other disease indicators in a comprehensive dataset.

Early maladaptive schemas, distress tolerance and self-injury in Iranian adolescents: serial mediation model of transdiagnostic factors

BACKGROUND

Non-suicidal self-injury (NSSI) is prevalent behaviour among adolescents. Although there are different etiological models of NSSI, there is a general lack of evidence-based, comprehensive and transdiagnostic models of NSSI in adolescents.

AIMS

The aim of this study was to investigate a model of transdiagnostic factors of NSSI in adolescents, testing a serial mediation model of the relationship between early maladaptive schemas (EMS), distress tolerance and NSSI through experiential avoidance and rumination.

METHOD

A community sample was identified of 1014 adolescents aged 13-17, of whom 425 had a history of NSSI. A serial mediation path analytic method was utilised to examine the relationships between NSSI and its associated functions as criterion variables, EMS and distress tolerance as predictors, experiential avoidance as the first mediator and rumination as the second mediator.

RESULTS

The path analytic model fit indices were good (X2/d.f. = 2.25, goodness of fit index = 0.98, normed fit index = 0.97, comparative fit index = 0.98, root mean square error of approximation = 0.054, standardised root mean squared residual = 0.028). Rumination significantly mediated the relationship between schemas of 'vulnerability to harm', 'emotional deprivation', 'social isolation', 'insufficient self-control', and NSSI frequency and intrapersonal functions. In serial fashion, experiential avoidance mediated the role of rumination in the relationship between social isolation, and insufficient self-control and NSSI frequency and intrapersonal functions. All indirect effects were significant.

CONCLUSIONS

Key indirect effects were found linking maladaptive schemas and distress tolerance to NSSI frequency, and NSSI intrapersonal functions via experiential avoidance and rumination. Thus, it is important to address these transdiagnostic factors with particular emphasis on the sequential mediating role of experiential avoidance and rumination in conceptualisation and therapeutic interventions for NSSI.

Individual differences in attention control: A meta-analysis and re-analysis of latent variable studies

A meta-analysis and re-analysis of prior latent variable studies was conducted in order to assess whether there is evidence for individual differences in broad attention control abilities. Data from 90 independent samples and over 23,000 participants suggested that most (84.4%) prior studies find evidence for a coherent attention control factor with average factor loadings of .51. This latent attention control factor was related to other cognitive ability factors including working memory, shifting, fluid intelligence, long-term memory, reading comprehension, and processing speed, as well as to self-reports of task-unrelated thoughts and task specific motivation. Further re-analyses and meta-analyses suggest that the results remained largely unchanged when considering various possible measurement issues. Examining the factor structure of attention control suggested evidence for sub-components of attention control (restraining, constraining and sustaining attention) which could be accounted for a by a higher-order factor. Additional re-analyses suggested that attention control represents a broad ability within models of cognitive abilities. Overall, these results provide evidence for attention control abilities as an important individual differences construct.

Impulsivity and neural correlates of response inhibition in bipolar disorder and their unaffected relatives: A MEG study

BACKGROUND

Response inhibition is a core cognitive impairment in bipolar disorder (BD), leading to increased impulsivity in BD. However, the relationship between the neural mechanisms underlying impaired response inhibition and impulsivity in BD is not yet clear. Individuals who are genetically predisposed to BD give a way of identifying potential endophenotypes.

METHODS

A total of 97 participants, including 39 patients with BD, 22 unaffected relatives (UR) of patients with BD, and 36 healthy controls performed a Go/No-Go task during magnetoencephalography. We carried out time-frequency and connectivity analysis on MEG data.

RESULTS

Decreased beta power, prolonged latency and increased peak frequency in rIFG, decreased beta power in pre-SMA and reduced rIFG-to-pre-SMA connectivity were found in BD relative to healthy controls. In the UR group, we found a decrease in the beta power of pre-SMA and prolonged latency of rIFG. Furthermore, increased motor impulsiveness in BD was related to abnormal alterations in beta oscillatory activity of rIFG and functional connectivity between rIFG and pre-SMA.

CONCLUSIONS

Hypoactivity activity in rIFG and impaired dominant role of rIFG in the prefrontal control network may underlie the neuropathology of response inhibition dysfunction, resulting increased motor impulsivity in BD. Our findings point to measuring rIFG dysfunction as a potential means of identifying individuals at genetic high risk for transition to BD disease expression.

Associations between disordered eating, internalizing symptoms, and behavioral and neural correlates of response inhibition in preadolescence

Response inhibition difficulties are reported in individuals with eating disorders (EDs), anxiety, and depression. Although ED symptoms and internalizing symptoms co-occur in preadolescence, there is limited research examining associations between these symptoms and response inhibition in this age group. This study is the first to investigate the associations between behavioral and neural markers of response inhibition, disordered eating (DE), and internalizing symptoms in a community sample of preadolescents. Forty-eight children (M age = 10.95 years, 56.3% male) completed a Go/NoGo task, whereas electroencephalography was recorded. Self-report measures of DE and internalizing symptoms were collected. Higher levels of anxiety and depression were associated with neural markers of suboptimal response inhibition (attenuated P3NoGo amplitudes) in preadolescence. In contrast, higher levels of depression were associated with greater response inhibition at a behavioral level. These findings suggest internalizing symptoms in preadolescence are associated with P3-indexed difficulties in evaluation and monitoring, but these are not sufficient to disrupt behavioral performance on a response inhibition task. This pattern may reflect engagement of compensatory processes to support task performance. DE was not significantly associated with response inhibition, suggesting that difficulties in response inhibition may only be reliably observed in more chronic and severe DE and ED presentations.

Neural underpinnings of response inhibition in substance use disorders: weak meta-analytic evidence for a widely used construct

RATIONALE

Substance use disorders (SUDs) rank among the most severely debilitating psychiatric conditions. Among others, decreased response inhibition capacities could make it more difficult for patients to abstain from drug use and maintain abstinence. However, meta-analyses on the neural basis of response inhibition in SUDs yielded conflicting results.

OBJECTIVE

In this study, we revisited the neuroimaging research field and summarized the existing fMRI literature on overt response inhibition (Go/NoGo and stop-signal paradigms) across different SUDs.

METHODS

We performed a systematic literature review and an activation likelihood estimation (ALE) meta-analysis to investigate the actual convergence of functional deviations observed in SUD samples. Results were further supplied by consecutive robustness measures and a post-hoc random-effects meta-analysis of behavioural data.

RESULTS

We identified k = 21 eligible studies for our analysis. The ALE analysis indicated a significant cluster of convergence with its statistical peak in the right anterior insula. Consecutive analyses, however, indicated this result was not robust and susceptible towards publication bias. Additionally, a post-hoc random effects meta-analysis of the behavioural parameters of Go/NoGo and stop-signal paradigms reported by the included studies revealed no significant differences in task performance comparing SUD samples and controls.

CONCLUSION

We discuss that the role of task-based response inhibition may require some refinement as an overarching marker for SUD pathology. Finally, we give a few prospects for future research that should be further explored in this context.

Both reactive and proactive control are deficient in children with ADHD and predictive of clinical symptoms

Cognitive control deficits are a hallmark of attention deficit hyperactivity disorder (ADHD) in children. Theoretical models posit that cognitive control involves reactive and proactive control processes but their distinct roles and inter-relations in ADHD are not known, and the contributions of proactive control remain vastly understudied. Here, we investigate the dynamic dual cognitive control mechanisms associated with both proactive and reactive control in 50 children with ADHD (16F/34M) and 30 typically developing (TD) children (14F/16M) aged 9-12 years across two different cognitive controls tasks using a within-subject design. We found that while TD children were capable of proactively adapting their response strategies, children with ADHD demonstrated significant deficits in implementing proactive control strategies associated with error monitoring and trial history. Children with ADHD also showed weaker reactive control than TD children, and this finding was replicated across tasks. Furthermore, while proactive and reactive control functions were correlated in TD children, such coordination between the cognitive control mechanisms was not present in children with ADHD. Finally, both reactive and proactive control functions were associated with behavioral problems in ADHD, and multi-dimensional features derived from the dynamic dual cognitive control framework predicted inattention and hyperactivity/impulsivity clinical symptoms. Our findings demonstrate that ADHD in children is characterized by deficits in both proactive and reactive control, and suggest that multi-componential cognitive control measures can serve as robust predictors of clinical symptoms.

A proof-of-concept study exploring the effects of impulsivity on a gamified version of the stop-signal task in children

This proof-of-concept study provides an appraisal of a remotely administered gamified Stop-Signal Task (gSST) for future use in studies using child sample. Performance on the standard Stop-Signal (SST) task has been shown previously to differentiate attention-deficit-hyperactivity-disorder groups from controls. As is the case with the SST, it was envisaged that those with greater impulsivity would perform worse than those with lower levels of impulsivity in the gSST. The potential advantage of the gSST is that it could be perceived as less monotonous than the original SST and has the potential to provide higher data quality in child samples, however future research will need to be conducted to determine this. The gSST was administered remotely via video chat to 30 child participants within a community sample aged 8-12 to investigate the effect of ADHD symptoms and intrinsic motivation on gSST performance. Qualitative data was collected based on feedback from participants to gain insight into how the gSST was received by participants. A positive correlation was observed between impulsive/hyperactivity and gSST performance, however there was insufficient evidence to suggest that impulsivity predicted performance. With regards to accuracy, results suggested that impulsivity level significantly predicted the rate of go-omission errors. No relationships were observed between intrinsic motivation inventory (IMI) subscales and performance or IMI and impulsivity. Nevertheless, mean IMI scores were overarchingly high for each of the IMI subscales, suggesting that regardless of performance and/or level of impulsive behaviour, the child sample obtained in this study demonstrated high levels of intrinsic motivation, which was supported by the predominantly positive subjective feedback provided by the child participants. The present study provides some evidence based on quantitative and qualitative results for the efficacy of gSST for use with children. Future research with a larger sample of children is warranted to examine how performance on the SST and gSST compare/differ.

ImGo: A Novel Tool for Behavioral Impulsivity Assessment Based on Go/NoGo Tasks

This manuscript aims to present a novel behavioral impulsivity test ImGo, which is suitable for impulsivity assessment in the general population. A series of three studies was conducted to validate its psychometric qualities. In Study 1 we describe the principles of ImGo and verify its test-retest and split-half reliability and its convergent validity with an impulsivity self-report scale and Stop Signal test. In Study 2 we re-analyze the convergent validity of ImGo with a Stop Signal test and examine the potential relationship between ImGo and oculomotor inhibition measured by an Anti-Saccades test. In Study 3 we present a robust research with a large sample size and investigate the discriminant validity of ImGo with tests of other related cognitive and executive processes. Backed by our findings from these studies we can safely claim ImGo is a powerful tool with a good level of reliability (both test-retest and split-half) and validity (convergent and discriminant). Its potential lies in its use in diagnostic and research practice of experts from various countries as the test has already been translated to 9 languages so far. The open-source Hypothesis platform, on which the ImGo test is running, provides the option of both individual and group testing in laboratory conditions as well as remotely through an internet browser.

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.

Neurobehavioral maturation of motor response inhibition in adolescence - A narrative review

Immature motor response inhibition in adolescence is considered contributory to adolescent risk-taking and externalizing behaviors. We review studies reporting age-related variations in motor response inhibition and MRI measurements from typically-developing adolescents. Reviewed studies measured response inhibition using one of three tasks-the Stop Signal Task, Go/No-Go, and Antisaccade Task. Task reliability appears to be particularly strong for the SST. Across tasks and study designs, results indicate that inhibitory control improves markedly through early adolescence. The trajectory of change in later adolescence and into young adulthood (i.e., linear or plateauing) varies depending on the task design. Neuroimaging studies identify adult-like response inhibition networks that are involved in behavioral development. The pros and cons of each task are discussed, including recommendations to guide future studies. Ongoing studies in large longitudinal datasets offer opportunities for further exploration of the shape of change in response inhibition, related neural regions, and associations with other affective and cognitive processes to identify potential impacts of motor response inhibition immaturities or individual differences on adolescent risk-taking behaviors.

Multimodal Virtual Reality-Based Assessment of Adult ADHD: A Feasibility Study in Healthy Subjects

Neuropsychological assessments are often surprisingly inaccurate in mapping clinically-reported attention-deficit hyperactivity disorder (ADHD) symptoms, presumably due to their low ecological validity. Virtual reality (VR) might offer a potential solution for this problem, given its capability to generate standardized and yet highly realistic virtual environments. As the first adaptation of existing virtual classroom scenarios to an adult population, we developed a Virtual Seminar Room (VSR) for multimodal characterization of ADHD symptoms. To test its feasibility, N = 35 healthy participants were immersed into the VSR via a head-mounted display and carried out a VR-embedded continuous performance task (CPT) under varying levels of distractions in two experimental blocks (24 min each). CPT performance, electroencephalography (EEG) measures, and head movements (actigraphy) were simultaneously recorded and analyzed offline. Although CPT performance remained constant throughout the task, head movements increased significantly from Block 1 to Block 2. In addition, EEG theta (4-7 Hz) and beta (13-30 Hz) power was higher during Block 1 than Block 2, and during distractor-present than distractor-absent phases. Moreover, P300 amplitudes were higher during Block 1 than Block 2, and P300 latencies were prolonged in distractor-absent compared with distractor-present phases. Although the paradigm awaits further improvements, this study confirms the general feasibility of the VSR and provides a first step toward a multimodal, ecologically valid, and reliable VR-based adult ADHD assessment.

Impulsive trait mediates the relationship between white matter integrity of prefrontal-striatal circuits and the severity of dependence in alcoholism

BACKGROUND

Alcohol dependence (AD) remains one of the major public health concerns. Impulsivity plays a central role in the transfer from recreational alcohol use to dependence and relapse. White matter dysfunction has been implicated in alcohol addiction behaviors and impulsivity. However, little is known about the role of systematic striatal structural connections underlying the mechanism of impulsive traits in AD.

METHODS

In our study, we used seed-based classification by probabilistic tractography with five target masks of striatal circuits to explore the differences in white matter integrity (fractional anisotropy, FA) in AD male patients (N = 51) and healthy controls (N = 27). We mainly explored the correlation between FA of the striatal circuits and impulsive traits (Barratt Impulsiveness Scale, BIS-11), and the mediation role of impulsivity in white matter integrity and the severity of alcohol dependence.

RESULTS

Compared with healthy controls, AD showed much lower FA in the left and right striatum-supplementary motor area (SMA) and left striatum-amygdala. We also found the decreased FA of right striatum-vlPFC was correlated with higher impulsivity. Besides, the relationship between reduced FA of right striatum-vlPFC and severity of dependence could be mediated by impulsivity.

CONCLUSION

In our study, we found disrupted white matter integrity in systematic striatal circuits in AD and the decreased FA of right striatum-vlPFC was correlated with higher impulsivity in AD. Our main findings provide evidence for reduced white matter integrity of systematic striatal circuits and the underlying mechanisms of impulsivity in male AD individuals.

Altered Neural Reactivity in Adolescents With Nonsuicidal Self-Injury During Exposure to Self-Injury Related Cues: Electrophysiological Evidence From a Two-Choice Oddball Paradigm

BACKGROUND

Nonsuicidal self-injury (NSSI) may be a type of addiction, that is characterized by cue reactivity. We aimed to explore the behavioral performance and neural reactivity during exposure to self-injury cues in adolescents with NSSI and major depressive disorder (MDD).

METHODS

Eighteen MDD patients, 18 MDD patients with NSSI, and 19 healthy controls (HC) were recruited to perform a two-choice oddball paradigm. All subjects were 12-18 years old. Neutral cues and self-injury related cues separately served as deviant stimuli. Difference waves in N2 and P3 (N2d and P3d) were derived from deviant waves minus standard waves. Accuracy cost and reaction time (RT) cost were used as behavioral indexes, while the N2d and P3d were used as electrophysiological indexes; the N2d reflects early conflict detection, and the P3d reflects the process of response inhibition.

RESULTS

No significant main effects of group or cue or an effect of their interaction were observed on accuracy cost and P3d latency. For RT cost, N2d amplitude, and N2d latency, there was a significant main effect of cue. For P3d amplitude, there was a significant main effect of cue and a significant group × cue interaction. In the NSSI group, the P3d amplitude with self-injury cues was significantly larger than that with neutral cues. However, there was no such effect in the MDD and HC groups.

CONCLUSIONS

Adolescents with NSSI showed altered neural reactivity during exposure to self-injury cue. Further studies with larger sample sizes are needed to confirm our results.

Adaptation and validation of a German version of the Dickman impulsivity inventory for the assessment of functional and dysfunctional impulsivity

Impulsive behavior tends to have a negative connotation in the sense that it is usually associated with detrimental or dysfunctional outcomes. However, under certain circumstances, impulsive behaviors may also have beneficial or functional outcomes. Dickman's Impulsivity Inventory (DII) measures these two distinct aspects of impulsivity, namely, dysfunctional impulsivity (the tendency to act with less forethought than do most people which leads to difficulties) and functional impulsivity (the tendency to act with little forethought when the situation is optimal). In the present study, we translated the DII into German and validated the German version in a sample of 543 adults. The original 23-item model was considered unsuitable for the German version as suggested by fit indices of a confirmatory factor analysis. Exploratory factor analyses rather supported a 16-item version. Further psychometric analyses and inferential statistical analyses on the final German DII indicated its appropriateness for use in German-speaking populations and support a two-factor solution of the DII. Finally, exploratory analyses on the German DII suggest differential relationships between dysfunctional and functional impulsivity and self-reported lifestyle-related variables (smoking, alcohol usage, and sports behavior).

GABAergic modulation of performance in response inhibition and interference control tasks

BACKGROUND

Inhibitory control is a crucial executive function with high relevance to mental and physical well-being. However, there are still unanswered questions regarding its neural mechanisms, including the role of the major inhibitory neurotransmitter, γ-aminobutyric acid (GABA).

AIMS

This study examined the effects of lorazepam (0.5 mg and 1 mg), a positive allosteric modulator at the GABA_A receptor, on response inhibition and interference control. We also explored the heterogeneity of inhibitory control and calculated delta plots to explore whether lorazepam affects the gradual build-up of inhibition and activation over time.

METHODS

N = 50 healthy participants performed antisaccade, Eriksen flanker and Simon tasks in a within-subjects, placebo-controlled, double-blind randomized design.

RESULTS

Lorazepam increased reaction time (RT) and error rates dose dependently in all tasks (p ⩽ 0.005). In the antisaccade and Simon tasks, lorazepam increased congruency effects for error rate (p ⩽ 0.029) but not RT (p ⩾ 0.587). In the Eriksen flanker task, both congruency effects were increased by the drug (p ⩽ 0.031). Delta plots did not reflect drug-induced changes in inhibition and activation over time. Delta plots for RT in the Simon task were negative-going, as expected, whereas those for the antisaccade and flanker tasks were positive-going.

CONCLUSIONS

This study provides evidence for GABAergic involvement in performance on response inhibition and interference control tasks. Furthermore, our findings highlight the diversity of the broader construct of inhibitory control while also pointing out similarities between different inhibitory control tasks. In contrast to RT and error rates, the cognitive processes indexed by delta plots may not be sensitive to GABAergic modulation.

Impulsivity and Its Relationship With Lisdexamfetamine Dimesylate Treatment in Binge Eating Disorder

High trait impulsivity is thought to contribute to the sense of loss of control over eating and impulses to binge eat experienced by those with binge eating disorder (BED). Lisdexamfetamine dimesylate (LDX), a drug approved for treatment of moderate to severe BED, has been shown to decrease impulsive features of BED. However, the relationship between LDX-related reductions of binge eating (BE) episodes and impulsivity has not yet been explored. Forty-one adults aged 18-40years with moderate to severe BED completed questionnaires and tasks assessing impulsivity at baseline and after 8weeks of 50-70mg of LDX. Twenty age-matched healthy controls were also assessed at two timepoints for normative comparison. Data were analysed using linear mixed models. BED participants exhibited increased self-reported motor, non-planning, cognitive and food-related impulsivity relative to controls but no differences in objective task-based measures of impulsivity. Food-related and non-planning impulsivity was significantly reduced by LDX, but not to normative levels. Individuals with higher baseline levels of motor and non-planning impulsivity, and loss of control over eating scores experienced the greatest reduction in BE frequency after 8weeks of LDX. Further, there were significant associations between the degree to which subjective loss of control over eating, non-planning impulsivity and BE frequency reduced after 8weeks of LDX. These data suggest that specific subjective measures of impulsivity may be able to predict who will have the greatest benefit from LDX treatment and that reductions in BE frequency may be moderated by concurrent reductions in non-planning impulsivity.

Impaired impulse inhibition of emotional stimuli in patients with borderline personality disorder

This study was aimed to investigate whether BPD patients showed impaired impulse inhibition of emotional and non-emotional stimuli and to explore relevant neuroelectrophysiological mechanisms. A total of 32 BPD patients and 32 matched healthy controls were recruited. Self-reported scales were used to measure psychiatric symptoms. The event-related potentials (ERPs) were recorded when subjects were performing neutral and emotional Stop Signal Task (SST). Group differences in self-reported scores, behavioral variables and ERPs were compared. The BPD group scored significantly higher on impulsivity, severity of BPD symptoms, levels of depression and anxiety than the control group. In neutral SST, no significant group differences were detected in the amplitude and latency of ERPs components induced. In emotional SST, the P2 amplitude of negative emotion was significantly larger than that of neutral emotion in Go trials. In Stop trials, the P2 amplitude of BPD group was significantly smaller than that of control group, and the N2 amplitude of BPD group was significantly greater than that of control group. BPD patients showed impaired inhibition of emotional stimuli rather than non-emotional stimuli. The deficits of emotional impulse control mainly exhibit at the early attention, stimulus evaluation and conflict detection stages.

Reaching to inhibit a prepotent response: A wearable 3-axis accelerometer kinematic analysis

The present work explores the distinctive contribution of motor planning and control to human reaching movements. In particular, the movements were triggered by the selection of a prepotent response (Dominant) or, instead, by the inhibition of the prepotent response, which required the selection of an alternative one (Non-dominant). To this end, we adapted a Go/No-Go task to investigate both the dominant and non-dominant movements of a cohort of 19 adults, utilizing kinematic measures to discriminate between the planning and control components of the two actions. In this experiment, a low-cost, easy to use, 3-axis wrist-worn accelerometer was put to good use to obtain raw acceleration data and to compute and break down its velocity components. The values obtained with this task indicate that with the inhibition of a prepotent response, the selection and execution of the alternative one yields both a longer reaction time and movement duration. Moreover, the peak velocity occurred later in time in the non-dominant response with respect to the dominant response, revealing that participants tended to indulge more in motor planning than in adjusting their movement along the way. Finally, comparing such results to the findings obtained by other means in the literature, we discuss the feasibility of an accelerometer-based analysis to disentangle distinctive cognitive mechanisms of human movements.

Sedentary time is related to deficits in response inhibition among adults with overweight and obesity: An accelerometry and event-related brain potentials study

Excessive sedentariness has been related to poorer cognitive control in adults. Sedentariness may compound obesity-related impairments in response inhibition, but its relationship to response inhibition remains poorly understood. This study investigated the relationship between accelerometer-measured sedentary time (ST, min/day), performance on the Oddball and NoGo tasks, N2 and P3-ERP indices of response inhibition and attentional control in 80 adults with overweight and obesity (55 females, M_age  = 35.2 ± 5.8 years, BMI = 32.8 ± 5.3 kg/m² ). ST was not related to performance on the Oddball task. However, more sedentary adults had larger P3b amplitude to targets. Higher ST was also related to increased attentional resource allocation during NoGo target and nontarget trials as indicated by higher P3b amplitudes across centroparietal sites (C1, Cz, C2, CP1, CPz, CP2; ps ≤ .03). ST was negatively indirectly related to target accuracy on NoGo trials through its association with faster response times to nontargets (95% percentile bootstrap CI for a standardized effect: -0.182, -0.014). ST was not related to N2 amplitude on either Oddball or NoGo target trials. Adjustment for moderate-to-vigorous physical activity (MVPA; all models), age (models with P3b NoGo target amplitude, N2 NoGo target amplitude and latency), and % fat mass (models with target NoGo accuracy and N2 NoGo target amplitude) did not modulate behavioral findings. MVPA did not significantly predict P3b amplitude. Our results suggest suboptimal response inhibition due to trading accuracy for speed and despite the upregulation of attentional resources among more sedentary adults with overweight and obesity.

Individual Differences in Intertemporal Choice

Intertemporal choice involves deciding between smaller, sooner and larger, later rewards. People tend to prefer smaller rewards that are available earlier to larger rewards available later, a phenomenon referred to as temporal or delay discounting. Despite its ubiquity in human and non-human animals, temporal discounting is subject to considerable individual differences. Here, we provide a critical narrative review of this literature and make suggestions for future work. We conclude that temporal discounting is associated with key socio-economic and health-related variables. Regarding personality, large-scale studies have found steeper temporal discounting to be associated with higher levels of self-reported impulsivity and extraversion; however, effect sizes are small. Temporal discounting correlates negatively with future-oriented cognitive styles and inhibitory control, again with small effect sizes. There are consistent associations between steeper temporal discounting and lower intelligence, with effect sizes exceeding those of personality or cognitive variables, although socio-demographic moderator variables may play a role. Neuroimaging evidence of brain structural and functional correlates is not yet consistent, neither with regard to areas nor directions of effects. Finally, following early candidate gene studies, recent Genome Wide Association Study (GWAS) approaches have revealed the molecular genetic architecture of temporal discounting to be more complex than initially thought. Overall, the study of individual differences in temporal discounting is a maturing field that has produced some replicable findings. Effect sizes are small-to-medium, necessitating future hypothesis-driven work that prioritizes large samples with adequate power calculations. More research is also needed regarding the neural origins of individual differences in temporal discounting as well as the mediating neural mechanisms of associations of temporal discounting with personality and cognitive variables.

Individual Differences in Inhibitory Control: A latent Variable Analysis

Inhibitory control represents a central component of executive functions and focuses on the ability to actively inhibit or delay a dominant response to achieve a goal. Although various tasks exist to measure inhibitory control, correlations between these tasks are rather small, partly because of the task impurity problem. To alleviate this problem, a latent variable approach has been previously applied and two closely related yet separable functions have been identified: prepotent response inhibition and resistance to distractor interference. The goal of our study was a) to replicate the proposed structure of inhibitory control and b) to extend previous literature by additionally accounting for speed-accuracy trade-offs, thereby potentially increasing explained variance in the investigated latent factors. To this end, 190 participants completed six inhibitory control tasks (antisaccade task, Stroop task, stop-signal task, flanker task, shape-matching task, word-naming task). Analyses were conducted using standard scores as well as inverse efficiency scores (combining response times and error rates). In line with previous studies, we generally found low zero-order correlations between the six tasks. By applying confirmatory factor analysis using standard reaction time difference scores, we were not able to replicate a satisfactory model with good fit to the data. By using inverse efficiency scores, a two-related-factor and a one-factor model emerged that resembled previous literature, but only four out of six tasks demonstrated significant factor loadings. Our results highlight the difficulty in finding robust inter-correlations between commonly used inhibitory control tasks, even when applying a latent variable analysis and accounting for speed-accuracy trade-offs.

Drawing alcohol craving process: A systematic review of its association with thought suppression, inhibition and impulsivity

Alcohol Use Disorder (AUD) is a worldwide public health problem. In recent years, there has been growing evidence supporting craving, the irrepressible desire to drink, as a major mechanism implicated in AUD. Impulsivity is identified as playing a significant role in craving in many studies. However, relationships with inhibition and thought suppression remain unclear in the existing literature. A systematic review was conducted to evaluate their associations in order to better understand the cognitive processes involved in craving.

Studies were identified by searching PubMed, PsycINFO and Web of Science using PRISMA procedure and PICOTS framework. There were included if they assessed craving and thought suppression or inhibition or impulsivity, and sample was composed of AUD participants.

Thirteen studies were included and were categorized in accordance with the evaluated cognitive process. The first part dealt with thought suppression and the second with impulsivity and inhibition. Four studies showed a positive association between thought suppression and increased craving. Two studies showed that poorer inhibition was associated with increased craving and four studies showed that impulsivity was positively associated with craving. Three studies showed a negative association between impulsivity and inhibition and higher craving.

Our review highlights the association of alcohol craving with poorer inhibition and greater impulsivity. Further investigations are needed to give support to different theories and lead to propose an integrative model involving the cognitive process of inhibition in alcohol craving.

Altered Risk-Taking Behavior in Early-Stage Bipolar Disorder With a History of Psychosis

Altered risk-taking propensity is an important determinant of functional impairment in bipolar disorder. However, prior studies primarily assessed patients with chronic illness, and risk-taking has not been evaluated in the early illness course. This study investigated risk-taking behavior in 39 euthymic early-stage bipolar disorder patients aged 16-40 years who were treated within 3 years from their first-episode mania with psychotic features and 36 demographically-matched healthy controls using the Balloon Analog Risk Task (BART), a well-validated risk-taking performance-based paradigm requiring participants to make responses for cumulative gain at increasing risk of loss. Relationships of risk-taking indices with symptoms, self-reported impulsivity, cognitive functions, and treatment characteristics were also assessed. Our results showed that patients exhibited significantly lower adjusted scores (i.e., average balloon pumps in unexploded trials) (p = 0.001), lower explosion rate (p = 0.007) and lower cumulative scores (p = 0.003) than controls on BART, indicating their suboptimal risk-taking performance with increased propensity for risk aversion. Risk-taking indices were not correlated with any symptom dimensions, self-reported impulsivity, cognitive functions or antipsychotic dose. No significant difference was observed between patients with and without antipsychotic medications on self-reported impulsivity or any of the BART performance indices. This is the first study to examine risk-taking behavior in early-stage bipolar disorder with history of psychosis and indicates that patients displayed altered risk-taking with increased risk aversion compared with controls. Further research is needed to clarify longitudinal trajectory of risk-taking propensity and its relationships with psychosis and functional outcome in the early stage of bipolar disorder.

Volitional eye movement control and ADHD traits: a twin study

BACKGROUND

Top-down volitional command of eye movements may serve as a candidate endophenotype of ADHD, an important function underlying goal-directed action in everyday life. In this twin study, we examined the relation between performance on a response inhibition eye-tracking paradigm and parent-rated ADHD traits in a population-based twin sample. We hypothesized that altered eye movement control is associated with the severity of ADHD traits and that this association is attributable to genetic factors.

METHODS

A total of 640 twins (320 pairs, 50% monozygotic) aged 9-14 years) from the Child and Adolescent Twin Study in Sweden (CATSS) participated. Twins performed the antisaccade task indexing inhibitory alterations as either direction errors (following exogenous cues rather than instructions) or premature anticipatory eye movements (failure to wait for cues). We calculated the associations of eye movement control and ADHD traits using linear regression mixed-effects models and genetic and environmental influences with multivariate twin models.

RESULTS

Premature anticipatory eye movements were positively associated with inattentive traits (β = .17; 95% CI: 0.04, 0.31), while controlling for hyperactive behaviors and other covariates. Both premature anticipatory eye movements and inattention were heritable (h²  = 0.40, 95% CI: 0.22, 0.56; h²  = 0.55; 95% CI: 0.42, 0.65; respectively), and their genetic correlation was small but statistically significant (r = .19, 95% CI: 0.02, 0.36). However, the genetic correlation did not remain significant after adjusting for covariates (age, sex, hyperactivity traits, IQ). No link was found between direction errors and ADHD traits.

CONCLUSIONS

This study indicates that there is a specific, genetically influenced, relation between top-down eye movement control and the inattentive traits typical of ADHD.

Reward history impacts attentional orienting and inhibitory control on untrained tasks

It has been robustly shown that stimuli with reward history receive attentional priority. However, the majority of this research tests reward history effects on attentional bias using similar tasks for both the reward learning phase and the unrewarded testing phase, which limits our understanding of how the effects of reward history generalize beyond the trained tasks and mental sets. Across two new experiments, the current study addresses these issues by first associating reward with a stimulus in a visual search paradigm, and then testing value-driven effects of that stimulus in untrained and unrewarded tasks, including a cueing paradigm, a go/no-go task, and a delay discounting task. Results of Experiment 1 demonstrate that history of reward association in a visual search task generalizes to value-driven attentional bias in a different attention paradigm (i.e., cueing), indicating these effects are indeed attributable to imbued value that can transfer to other tasks beyond that in which the reward was trained. The results of Experiment 2 demonstrate that in addition to eliciting attentional orienting on untrained tasks, reward history can lead to better inhibitory control in the go/no-go task. We find no evidence for reward history effects in the delay discounting task. Together, these experiments demonstrate that when the reward association task is in the attention domain, reward history modulates attentional priority, and this effect generalizes to untrained and unrewarded tasks that utilize both spatial and nonspatial attention.

The role of inhibitory control and decision-making in the course of Internet gaming disorder

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is associated with impaired inhibitory control and more impulsive decision-making. However, it remains unclear whether these associations are cross-sectional or predictive. We aimed to test the hypotheses that lower inhibitory control and more impulsive decision-making correlate with, are predicted by and predict more time spent on gaming and higher IGD severity.

METHODS

A stratified convenience sample of 70 male participants (18-21 years) was recruited to achieve broad data variability for hours spent on gaming and IGD severity. In three annual assessments (T1, T2, T3), we measured gaming behaviour and IGD severity using the Video Game Dependency Scale (CSAS-II). Both gaming-related measures were correlates (T1), predictors (T2), or outcomes (T3) of inhibitory control and decision making, which were assessed at T2 using a go/no-go task and an intertemporal-choice task, respectively.

RESULTS

Higher IGD severity at T1 predicted more impulsive decision-making at T2 (β = 0.45, 95% CI = 0.14-0.76). Lower inhibitory control at T2 predicted more hours spent on gaming at T3 (β = -0.13, 95% CI = -0.25 to -0.02). We found weak or no evidence for the other associations.

DISCUSSION AND CONCLUSIONS

Lower inhibitory control predicts more time spent gaming, possibly due to insufficient top-down regulation of the behaviour. Impulsive decision-making is rather a consequence of IGD than a predictor, which may be due to altered reward learning. One-dimensional etiological assumptions about the relationship between neurocognitive impairments and IGD seem not to be appropriate for the complexity of the disorder.

Controlled sleep deprivation as an experimental medicine model of schizophrenia: An update

In recent years there has been a surge of interest and corresponding accumulation of knowledge about the role of sleep disturbance in schizophrenia. In this review, we provide an update on the current status of experimentally controlled sleep deprivation (SD) as an experimental medicine model of psychosis, and also consider, given the complexity and heterogeneity of schizophrenia, whether this (state) model can be usefully combined with other state or trait model systems to more powerfully model the pathophysiology of psychosis. We present evidence of dose-dependent aberrations that qualitatively resemble positive, negative and cognitive symptoms of schizophrenia as well as deficits in a range of translational biomarkers for schizophrenia, including prepulse inhibition, smooth pursuit and antisaccades, following experimentally controlled SD, relative to standard sleep, in healthy volunteers. Studies examining the combination of SD and schizotypy, a trait model of schizophrenia, revealed only occasional, task-dependent superiority of the combination model, relative to either of the two models alone. Overall, we argue that experimentally controlled SD is a valuable experimental medicine model of schizophrenia to advance our understanding of the pathophysiology of the clinical disorder and discovery of more effective or novel treatments. Future studies are needed to test its utility in combination with other, especially state, model systems of psychosis such as ketamine.

Threat-sensitivity in affective disorders: A case-control study

BACKGROUND

Anxiety disorders are highly comorbid with major depression but differ in their symptom profiles and pharmacological responses. Threat-sensitivity may explain such differences, yet research on its relationship to specific disorders is lacking.

METHODS

One-hundred patients (71 women) and 35 healthy controls (23 women) were recruited. Thirty-five had Panic Disorder (PD), 32 had Generalized Anxiety Disorder (GAD) and 33 Major Depressive Disorder (MDD). Threat-sensitivity was measured via behaviour (Joystick Operated Runway Task; JORT) and self-report (Fear Survey Schedule; FSS).

RESULTS

Behavioural sensitivity to simple threat was higher in females compared to males (p = .03). Self-reported sensitivity to simple threat (FSS Tissue Damage Fear) was higher in PD patients compared to other groups (p ≤ .007) and in GAD patients compared to controls (p = .02). Behavioural sensitivity to complex threat was higher in females than males (p = .03) and a group by sex interaction (p = .01) indicated that this difference was largest in PD patients. Self-reported sensitivity to complex threat (FSS Social Fear) was higher in all patients compared to controls (p ≤ .001). Females scored higher than males on FSS Tissue Damage Fear and FSS Social Fear).

CONCLUSIONS

Our findings oppose the simple/complex threat dichotomy, instead suggesting elevated sensitivity to physical threat differentiates anxiety disorders from MDD, whereas elevated sensitivity to social threat is associated with both anxiety disorders and MDD.

Interference scores have inadequate concurrent and convergent validity: Should we stop using the flanker, Simon, and spatial Stroop tasks?

BACKGROUND

Two-hundred one college undergraduates completed four nonverbal interference tasks (Simon, spatial Stroop, vertical Stroop, and flanker) and trait scales of self-control and impulsivity. Regression analyses tested 11 predictors of the composite interference scores derived from three of the four tasks and each task separately. The purpose of the study was to examine the relationships between laboratory measures of self-control, self-report measures, and the degree to which control might be related to extensive experience in activities that logically require self-control.

RESULTS

Fluid intelligence and sex were significant predictors of the composite measure, but bilingualism, music training, video gaming, mindfulness/meditation, self-control, impulsivity, SES, and physical exercise were not.

CONCLUSIONS

Common laboratory measures of inhibitory control do not correlate with self-reported measures of self-control or impulsivity and consequently appear to be measuring different constructs. Bilingualism, mindfulness/meditation, playing action video games, and music training or performance provide weak and inconsistent improvements to laboratory measures of interference control. Flanker, Simon, and spatial Stroop effects should not be used or interpreted as measures of domain-general inhibitory control.

Trait impulsiveness and response inhibition in young adults: Moderating role of resting respiratory sinus arrhythmia

Trait impulsiveness is a multifaceted construct that includes motor-, attention/cognitive- and non-planning facets, but how specific impulsiveness facets are associated with the deficit of response inhibition is not well understood. Resting respiratory sinus arrhythmia (RSA), which is considered as an index of cardiac vagal tone has been demonstrated to play a moderating role in the associations between many individual's variables. Whether resting RSA moderates the relationships between the facets of trait impulsiveness and response inhibition remains unknown. To examine these issues, data of self-reported trait impulsiveness, as assessed using the Barratt Impulsiveness Scale (BIS-II), 5-min resting RSA, and response accuracy (ACC) on a modified Go/NoGo task were collected from 132 college students. Results indicated that ACC of NoGo condition on the Go/NoGo task was negatively correlated with BIS motor and BIS total. Trait motor impulsiveness negatively predicted ACC of NoGo condition on the Go/NoGo task in the low resting RSA group but not in the high resting RSA group. This finding suggests that cardiac vagal tone could moderate the association between trait impulsiveness, especially motor impulsiveness, and deficits of response inhibition.

Genetic Influences on Social Relationships: Sex Differences in the Mediating Role of Personality and Social Cognition

Objectives

In humans (and primates more generally), evolutionary fitness arises by two separate routes: conventional reproduction build around dyadic relationships and, reflecting the processes of group augmentation selection, how well individuals are embedded in their community. These processes are facilitated by a suite of genetically inherited neuroendocrines and neurotransmitters. It is not, however, known whether these effects are directly due to genetic factors or are mediated by aspects of personality, or whether there are sex differences in the way this is organised.

Methods

We examine whether dispositional factors related to the processing of social information, such as personality (Big 5 and Impulsivity), attachment style (Anxious and Avoidant dimensions) and sociocognitive capacity (emotion recognition) mediate associations between variation in receptor genes for oxytocin, vasopressin, beta-endorphin, dopamine, serotonin, testosterone and two core social relationship indices (the Sociosexual Orientation Index [SOI] and Support Network size).

Results

In men, variation in dopamine genes indirectly influences SOI through its effect on Impulsivity. In contrast, in women, variation in endorphin and vasopressin genes independently affect Openness to Experience, which mediates indirect effects of these genes on SOI. Moreover, endorphin gene variation also impacts on Network Size in women (but not men), via Extraversion.

Conclusions

These findings reveal that dispositional aspects of personality mediate some genetic effects on behaviour, thereby extending our understanding of how genetic and dispositional variation interact to determine individual differences in human sexual and social cognition and behaviour. The differences between the sexes seem to reflect differences in the two sexes’ social strategies.

A fractionated analysis of hot and cool self-regulation in cigarette smokers from different socioeconomic backgrounds

Smoking cigarettes and low socioeconomic status (SES) are both related to impaired cognition. However, it is unknown whether people of lower SES, who comprise most tobacco smokers worldwide, are more susceptible to cognitive impairment associated with smoking. In this non-randomized, cross-sectional study we investigated the effects of cigarette smoking, SES and their interaction on dissociable executive or “cool” and “hot” measures of behavioural self-regulation. Participants (n = 80) were selected among young physically and mentally healthy smokers and non-smokers who had graduated high school and were from different SES backgrounds. Cool self-regulation was measured by executive function tasks that tap inhibition, updating, shifting, dual tasking, planning, access to long-term memory (semantic fluency), and working memory capacity. Hot measures assessed self-reported impulsivity, delay discounting and risk taking. Exposure to tobacco (cotinine, exhaled carbon monoxide, tobacco dependence, cigarette consumption) was assessed to determine to what extent it mediated the cognitive effects of smoking. Nicotine abstinence and its acute effects were controlled, as were sex, age, schooling, and psychiatric symptoms despite the fact that smokers and non-smokers were selected as being as similar as possible in these demographic characteristics. Lower SES (less years of parental schooling) was associated with worse performance on tasks that measured all cool domains except dual tasking and fluency, while smoking status was related to impaired delayed discounting and impulsivity (hot domains), effects that were not mediated by tobacco exposure. Smoking and SES, however, did not interact. In short, impaired performance in measures of most cool skills was associated with SES irrespective of smoking status; in contrast, regardless of SES, smokers showed specific impairment in hot self-regulation domains (more difficulty resisting immediate temptations and weighing future consequences of actions). Possible explanations for the lack of mediation of tobacco exposure on hot skills of smokers are discussed.

Associations Between Neuroticism and Executive Function Outcomes: Response Inhibition and Sustained Attention on a Continuous Performance Test

There are known relationships between psychopathology, personality, and executive function (EF), though the association between personality and EF, independent of psychopathology, remains understudied. The present study investigated relationships between Five Factor Model personality traits and indices of response inhibition, sustained attention, and response variability on a continuous performance test (CPT) among 50 healthy adults (male = 27, female = 23; Mage = 19.9 years, range 18–24 years) of primarily Caucasian descent (58.0%). Participants performed an open-source CPT, the Psychology Experiment Building Language Battery Test of Attentional Vigilance (TOAV), and completed self-ratings of conscientiousness, extraversion, and neuroticism on an inventory developed from the public-domain International Personality Item Pool. After controlling for the influences of age, gender, and other personality traits, neuroticism was significantly associated with faster error reaction time and a higher frequency of multiple responses. Neuroticism was also nominally predictive of more frequent commission errors and faster correct and mean reaction time. The present findings indicate that neuroticism is associated with error-prone behavioral performance on a CPT, suggesting that a propensity to experience negative emotions may manifest as impulsivity and hyperactivity on performance-based measures of EF.

The Urge to Decide and Act: Implications for Brain Function and Dysfunction

Humans and other animals are motivated to act so as to maximize their subjective reward rate. Here, we propose that reward rate maximization is accomplished by adjusting a context-dependent “urgency signal,” which influences both the commitment to a developing action choice and the vigor with which the ensuing action is performed. We review behavioral and neurophysiological data suggesting that urgency is controlled by projections from the basal ganglia to cerebral cortical regions, influencing neural activity related to decision making as well as activity related to action execution. We also review evidence suggesting that different individuals possess specific policies for adjusting their urgency signal to particular contextual variables, such that urgency constitutes an individual trait which jointly influences a wide range of behavioral measures commonly related to the overall quality and hastiness of one’s decisions and actions. Consequently, we argue that a central mechanism for reward rate maximization provides a potential link between personality traits such as impulsivity, as well as some of the motivation-related symptomology of clinical disorders such as depression and Parkinson’s disease.

Inhibitory control and emotion dysregulation: A framework for research on anxiety

While emotional dysregulation is a broad construct, the current paper adopts a narrow approach to facilitate translational neuroscience research on pediatric anxiety. The paper first presents data on an adapted version of the antisaccade task and then integrates these data into a research framework. Data on an adapted version of the antisaccade task were collected in 57 youth, including 35 seeking treatment for an anxiety disorder. Associations were examined between performance on the antisaccade task and (a) age, (b) performance on other cognitive-control tasks (i.e., the stop-signal delay and flanker tasks), and (c) level of anxiety symptoms. Better performance on the antisaccade task occurred in older relative to younger subjects and correlated with better performance on the flanker task. Across the 57 youth, higher levels of anxiety correlated with shorter latency for correct antisaccades. These data can be placed within a three-step framework for translational neuroscience research. In the first step, a narrow index of emotion dysregulation is targeted. In the second step, this narrow index is linked to other correlated indicators of the same underlying narrow latent construct. In the third and final step, associations are examined with clinical outcomes and response to treatment.

Individual Differences in Sensitivity to Visuomotor Discrepancies

This study explored whether sensitivity to visuomotor discrepancies, specifically the ability to detect and respond to loss of control over a moving object, is associated with other psychological traits and abilities. College-aged adults performed a computerized tracking task which involved keeping a cursor centered on a moving target using keyboard controls. On some trials, the cursor became unresponsive to participants' keypresses. Participants were instructed to immediately press the space bar if they noticed a loss of control. Response times (RTs) were measured. Additionally, participants completed a battery of behavioral and questionnaire-based tests with hypothesized relationships to the phenomenology of control, including measures of constructs such as locus of control, impulsiveness, need for cognition (NFC), and non-clinical schizotypy. Bivariate correlations between RTs to loss of control and high order cognitive and personality traits were not significant. However, a step-wise regression showed that better performance on the pursuit rotor task predicted faster RTs to loss of control while controlling for age, signal detection, and NFC. Results are discussed in relation to multifactorial models of the sense of agency.

Cognitive Measures and Performance on the Antisaccade Eye Movement Task

The antisaccade (AS) task is considered a prominent measure of inhibitory control, but it is still unclear which cognitive processes are used for successful performance of the task. Previous results have provided evidence for the involvement of several processes, including working memory (WM), inhibition and attention. Thus, the aim of this study was to explore, using a range of neuropsychological tests, which cognitive factors predict individual differences in AS performance. To do so, 143 healthy participants underwent a battery including tests measuring inhibition, working memory, cognitive flexibility, sustained attention, IQ and fluency. Hierarchical stepwise regression analyses were conducted to assess the association with AS performance. Performance on the Trail-Making-Test, version B (TMT-B), a test measuring flexibility, divided attention and WM, was found to significantly predict AS latency. Rapid Visual Information Processing (RVIP), used to assess sustained attention and WM, significantly predicted AS error rate. Other cognitive measures, however, did not significantly predict AS performance. Bayesian Model Averaging supported these conclusions and showed that non-significant predictors are unlikely to be associated with AS outcomes. Several explanations are provided for the associations of TMT-B and RVIP with AS performance; as the tests measure a range of different cognitive processes, interpretation of these results remains less clear. For a better understanding of the cognitive mechanisms underlying AS performance, future research should make use of a wider range of attention and WM tests.

Examining the link between reward and response inhibition in individuals with substance abuse tendencies

BACKGROUND

Substance use problems are often characterized by dysregulation in reward sensitivity and inhibitory control. In line with this representation, the goal of this investigation was to determine how substance abuse tendencies among university students affect incentivized response inhibition. Additionally, this study examined whether striatal dopamine moderates the impact of substance use on response inhibition performance.

METHODS

The sample included ninety-eight university students. Participants completed this prospective experimental study at an on-campus laboratory. All participants completed substance abuse and disinhibition subscales of the Externalizing Spectrum Inventory-Brief Form. Using a within-subjects design, participants then performed the Stop Signal Task under both neutral (unrewarded) and reward conditions, in which correct response cancellations resulted in a monetary reward. Striatal tonic dopamine levels were operationalized using spontaneous eyeblink rate.

RESULTS

The outcome measures were Stop Signal Reaction Time (SSRT) performance in the unrewarded and rewarded phases of the task. A hierarchical linear regression analysis, controlling for trait disinhibition, age, gender, and cigarette smoking status, identified an interactive effect of substance use and striatal dopamine levels on incentivized SSRT. Substance abuse tendencies were associated with slower SSRT and thus poorer inhibitory control under reward conditions among individuals with low levels of striatal dopamine (F = 7.613, p = .007).

CONCLUSIONS

This work has implications for research examining advanced drug use trajectories. In situations in which rewards are at stake, drug users with low tonic dopamine may be more motivated to seek those rewards at the expense of regulating inhibitory control.

Reliability of triggering inhibitory process is a better predictor of impulsivity than SSRT

The ability to control behaviour is thought to rely at least partly on adequately suppressing impulsive responses to external stimuli. However, the evidence for a relationship between response inhibition ability and impulse control is weak and inconsistent. This study investigates the relationship between response inhibition and both self-report and behavioural measures of impulsivity as well as engagement in risky behaviours in a large community sample (N = 174) of healthy adolescents and young adults (15-35 years). Using a stop-signal paradigm with a number parity go task, we implemented a novel hierarchical Bayesian model of response inhibition that estimates stop-signal reaction time (SSRT) as a distribution and also accounts for failures to react to the stop-signal (i.e., "trigger failure"), and failure to react to the choice stimulus (i.e., "go failure" or omission errors). In line with previous studies, the model reduced estimates of SSRT by approximately 100 ms compared with traditional non-parametric SSRT estimation techniques. We found significant relationships between behavioural and self-report measures of impulsivity and traditionally estimated SSRT, that did not hold for the model-based SSRT estimates. Instead, behavioural impulsivity measures were correlated with rate of trigger failure. The relationship between trigger failure and impulsivity suggests that the former may index a higher order inhibition process, whereas SSRT may index a more automatic inhibition process. We suggest that the existence of distinct response inhibition processes that may be associated with different levels of cognitive control.

Effects of ketamine on brain function during response inhibition

INTRODUCTION

The uncompetitive N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonist ketamine has been proposed to model symptoms of psychosis. Inhibitory deficits in the schizophrenia spectrum have been reliably reported using the antisaccade task. Interestingly, although similar antisaccade deficits have been reported following ketamine in non-human primates, ketamine-induced deficits have not been observed in healthy human volunteers.

METHODS

To investigate the effects of ketamine on brain function during an antisaccade task, we conducted a double-blind, placebo-controlled, within-subjects study on n = 15 healthy males. We measured the blood oxygen level dependent (BOLD) response and eye movements during a mixed antisaccade/prosaccade task while participants received a subanesthetic dose of intravenous ketamine (target plasma level 100 ng/ml) on one occasion and placebo on the other occasion.

RESULTS

While ketamine significantly increased self-ratings of psychosis-like experiences, it did not induce antisaccade or prosaccade performance deficits. At the level of BOLD, we observed an interaction between treatment and task condition in somatosensory cortex, suggesting recruitment of additional neural resources in the antisaccade condition under NMDAR blockage.

DISCUSSION

Given the robust evidence of antisaccade deficits in schizophrenia spectrum populations, the current findings suggest that ketamine may not mimic all features of psychosis at the dose used in this study. Our findings underline the importance of a more detailed research to further understand and define effects of NMDAR hypofunction on human brain function and behavior, with a view to applying ketamine administration as a model system of psychosis. Future studies with varying doses will be of importance in this context.

Linking Cognitive Measures of Response Inhibition and Reward Sensitivity to Trait Impulsivity

Impulsivity is regarded as a multifaceted construct that comprises two dimensions: rapid-response impulsivity and reward-delay impulsivity. It is unclear, however, which aspects of trait impulsivity, as assessed by self-report measures are related to rapid-response impulsivity and/or to reward-delay impulsivity, as different results have been reported in studies using both self-report and cognitive measures. This study aimed to directly relate self-report measures of impulsivity to cognitive measures of impulsivity in individuals at low- or high-levels on two impulsivity dimensions, specifically rapid-response impulsivity and reward-delay impulsivity. Participants were classified into high- or low-impulsivity groups based on (1) level of rapid-response impulsivity (determined by BIS-11 Motor subscale scores); (2) level of reward-delay impulsivity (determined by BIS/BAS subscale scores); and (3) a combination of rapid-response impulsivity and reward-delay impulsivity levels. Impulsivity was assessed using Go/No-Go, Stop-Signal and Delay-Discounting tasks and self-report measures. The high rapid-response impulsivity group showed significantly higher reward-delay impulsivity on both, the Delay-Discounting tasks and on self-report measures assessing reward-delay impulsivity, than the low-risk group. Based on the level of reward-delay impulsivity, the high reward-delay impulsivity group scored significantly higher on task-based (cognitive) and self-report measures assessing rapid-response inhibition than the low reward-delay impulsivity group. Combining both dimensions of impulsivity showed that the high-impulsivity group performed significantly worse in rapid-response paradigms and temporally discounted significantly more impulsively than the low-impulsivity group. Thus, combined impulsivity factors provide better assessment of impulsivity than each dimension alone. In conclusion, robust differences in impulsivity can be identified in non-clinical young adults.

Cerebral blood flow modulations during antisaccade preparation in chronic hypotension

In addition to symptoms including fatigue, dizziness, reduced drive, or mood disturbance, individuals with chronic low blood pressure (hypotension) frequently report cognitive complaints. While attentional deficits have been empirically confirmed, it is still unknown whether the impairments also encompass executive functions. This study investigated cerebral blood flow modulations in hypotension during a precued antisaccade/prosaccade task requiring the executive function of proactive inhibition in addition to preparatory attention. Using functional transcranial Doppler sonography, bilateral blood flow velocities in the middle cerebral arteries (MCA) were recorded in 39 hypotensive and 40 normotensive participants. In the task, a stimulus appeared left or right of a fixation point 5 s after a cuing stimulus; subjects had to move their gaze to the mirror image position of the stimulus (antisaccade) or toward it (prosaccade control condition). Video-based eye tracking was used for ocular recording. A right dominant MCA blood flow increase arose during task preparation, which was smaller in hypotensive than normotensive participants. In addition, hypotensive participants exhibited lower peak velocity of the saccadic response. The extent of the reductions in blood flow and task performance in hypotension did not differ between antisaccade and prosaccade conditions. The smaller MCA flow increase may reflect reduced activity in the dorsolateral prefrontal and inferior parietal cortices during proactive inhibition and preparatory attention in hypotension. Given that group differences in blood flow and performance arose independent of task complexity and executive function load, hypotension may be characterized by basic attentional impairments rather than particular executive function deficits.

Low and variable correlation between reaction time costs and accuracy costs explained by accumulation models: Meta-analysis and simulations

The underpinning assumption of much research on cognitive individual differences (or group differences) is that task performance indexes cognitive ability in that domain. In many tasks performance is measured by differences (costs) between conditions, which are widely assumed to index a psychological process of interest rather than extraneous factors such as speed-accuracy trade-offs (e.g., Stroop, implicit association task, lexical decision, antisaccade, Simon, Navon, flanker, and task switching). Relatedly, reaction time (RT) costs or error costs are interpreted similarly and used interchangeably in the literature. All of this assumes a strong correlation between RT-costs and error-costs from the same psychological effect. We conducted a meta-analysis to test this, with 114 effects across a range of well-known tasks. Counterintuitively, we found a general pattern of weak, and often no, association between RT and error costs (mean r = .17, range -.45 to .78). This general problem is accounted for by the theoretical framework of evidence accumulation models, which capture individual differences in (at least) 2 distinct ways. Differences affecting accumulation rate produce positive correlation. But this is cancelled out if individuals also differ in response threshold, which produces negative correlations. In the models, subtractions between conditions do not isolate processing costs from caution. To demonstrate the explanatory power of synthesizing the traditional subtraction method within a broader decision model framework, we confirm 2 predictions with new data. Thus, using error costs or RT costs is more than a pragmatic choice; the decision carries theoretical consequence that can be understood through the accumulation model framework. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Neural correlates of proactive and reactive inhibition of saccadic eye movements

Although research on goal-directed, proactive inhibitory control (IC) and stimulus-driven, reactive IC is growing, no previous study has compared proactive IC in conditions of uncertainty with regard to upcoming inhibition to conditions of certain upcoming IC. Therefore, we investigated effects of certainty and uncertainty on behavior and blood oxygen level dependent (BOLD) signal in proactive and reactive IC. In two studies, healthy adults performed saccadic go/no-go and prosaccade/antisaccade tasks. The certainty manipulation had a highly significant behavioral effect in both studies, with inhibitory control being more successful under certain than uncertain conditions on both tasks (p ≤ 0.001). Saccadic go responses were significantly less efficient under conditions of uncertainty than certain responding (p < 0.001). Event-related functional magnetic resonance imaging (fMRI) (one study) revealed a dissociation of certainty- and uncertainty-related proactive inhibitory neural correlates in the go/no-go task, with lateral and medial prefrontal and occipital cortex showing stronger deactivations during uncertainty than during certain upcoming inhibition, and lateral parietal cortex being activated more strongly during certain upcoming inhibition than uncertainty or certain upcoming responding. In the antisaccade task, proactive BOLD effects arose due to stronger deactivations in uncertain response conditions of both tasks and before certain prosaccades than antisaccades. Reactive inhibition-related BOLD increases occurred in inferior parietal cortex and supramarginal gyrus (SMG) in the go/no-go task only. Proactive IC may imply focusing attention on the external environment for encoding salient or alerting events as well as inhibitory mechanisms that reduce potentially distracting neural processes. SMG and inferior parietal cortex may play an important role in both proactive and reactive IC of saccades.

Is experience in multi-genre video game playing accompanied by impulsivity?

Developing impulsivity has been one of the main concerns thought to arise from the increasing popularity of video gaming. Most of the relevant literature has treated gamers as pure-genre players (i.e. those who play only a specific genre of game). However, it is not clear how impulsivity is associated with different genres of games in multi-genre gamers, given that there is increasing diversity in the games played by individuals. In this study, we compared 33 gamers to 23 non-gamers in a go/no-go task: the Continuous Performance Test (CPT). To evaluate whether or not impulsivity occurs as a trade-off between speed and accuracy, we emphasised fast performance to all participants. Then, to examine the ability to predict impulsivity from game genre-hours, we fitted separate multiple regression models to several dependent variables. As an additional measure, we also compared groups in an antisaccade task. In the CPT, gamers showed a trend towards significantly faster reaction time (RT), accompanied by higher false alarm rate (FAR) and more risk-taking response bias (β), suggesting impulsive responses. Interestingly, there was a significant negative correlation between RT and FAR across all participants, suggesting an overall speed-accuracy trade-off strategy, perhaps driven by the emphasis on speed during task instruction. Moreover, time spent on role playing games (RPG) and real-time strategy (RTS) games better predicted FAR and β than did time spent on action and puzzle games. In the antisaccade task; however, gamers showed a shorter antisaccade latency but a comparable error rate in comparison with non-gamers. There was no specific game genre which could predict performance in the antisaccade task. Altogether, there was no evidence of oculomotor impulsivity in gamers; however, the CPT results suggested the presence of impulsive responses in gamers, which might be the result of a speed-accuracy trade-off. Furthermore, there was a difference in game genres, with time spent on RPG and RTS games being accompanied by greater probability of impulsive responses. Training studies are required to investigate the causality of different video game genres on the development of impulsivity.

Association of Schizotypy With Dimensions of Cognitive Control: A Meta-Analysis

Schizotypy is defined as a time-stable multidimensional personality trait consisting of positive, negative, and disorganized facets. Schizotypy is considered as a model system of psychosis, as there is considerable overlap between the 2 constructs. High schizotypy is associated with subtle but fairly widespread cognitive alterations, which include poorer performance in tasks measuring cognitive control. Similar but more pronounced impairments in cognitive control have been described extensively in psychosis. We here sought to provide a quantitative estimation of the effect size of impairments in schizotypy in the updating, shifting, and inhibition dimensions of cognitive control. We included studies of healthy adults from both general population and college samples, which used either categorical or correlative designs. Negative schizotypy was associated with significantly poorer performance on shifting (g = 0.32) and updating (g = 0.11). Positive schizotypy was associated with significantly poorer performance on shifting (g = 0.18). There were no significant associations between schizotypy and inhibition. The divergence in results for positive, negative, and disorganized schizotypy emphasizes the importance of examining relationships between cognition and the facets of schizotypy rather than using the overall score. Our findings also underline the importance of more detailed research to further understand and define this complex personality construct, which will also be of importance when applying schizotypy as a model system for psychosis.