A meta-analytic review of the sensitivity of the Wisconsin Card Sorting Test to frontal and lateralized frontal brain damage

Post-stroke urinary incontinence is associated with behavior control deficits and overactive bladder

BACKGROUND

Although urinary incontinence in stroke survivors can substantially impact the patient's quality of life, the underlying neuropsychological mechanisms and its neural basis have not been adequately investigated. Therefore, we investigated this topic via neuropsychological assessment and neuroimaging in a cross-sectional study.

METHODS

We recruited 71 individuals with cerebrovascular disease. The relationship between urinary incontinence and neuropsychological indices was investigated using simple linear regression analysis or Mann-Whitney U test, along with other explanatory variables, e.g., severity of overactive bladder. Variables with a p-value of <0.1 in the simple regression analysis were entered in the final multiple linear regression model to control for potential confounding factors. To carry out an in-depth examination of the neuroanatomical substrate for urinary incontinence, voxel-based lesion-behavior mapping was performed using MRIcron software.

RESULTS

Behavioral control deficits and severity of overactive bladder were closely related to severity of urinary incontinence. The voxel-based lesion-behavior mapping suggests a potential role for ventromedial prefrontal cortex lesioning in the severity of urinary incontinence, although this association is not statistically significant.

CONCLUSIONS

Post-stroke urinary incontinence is closely related to two factors: neurogenic overactive bladder, a physiological disinhibition of micturition reflex, and cognitive dysfunction, characterized by behavior control deficits.

In relentless pursuit of the white whale: A role for the ventral midline thalamus in behavioral flexibility and adaption?

The reuniens (Re) nucleus is located in the ventral midline thalamus. It has fostered increasing interest, not only for its participation in a variety of cognitive functions (e.g., spatial working memory, systemic consolidation, reconsolidation, extinction of fear or generalization), but also for its neuroanatomical positioning as a bidirectional relay between the prefrontal cortex (PFC) and the hippocampus (HIP). In this review we compile and discuss recent studies having tackled a possible implication of the Re nucleus in behavioral flexibility, a major PFC-dependent executive function controlling goal-directed behaviors. Experiments considered explored a possible role for the Re nucleus in perseveration, reversal learning, fear extinction, and set-shifting. They point to a contribution of this nucleus to behavioral flexibility, mainly by its connections with the PFC, but possibly also by those with the hippocampus, and even with the amygdala, at least for fear-related behavior. As such, the Re nucleus could be a crucial crossroad supporting a PFC-orchestrated ability to cope with new, potentially unpredictable environmental contingencies, and thus behavioral flexibility and adaption.

The future of neuropsychology is digital, theory-driven, and Bayesian: a paradigmatic study of cognitive flexibility

Introduction

This study explores the transformative potential of digital, theory-driven, and Bayesian paradigms in neuropsychology by combining digital technologies, a commitment to evaluating theoretical frameworks, and Bayesian statistics. The study also examines theories of executive function and cognitive flexibility in a large sample of neurotypical individuals (N = 489).

Methods

We developed an internet-based Wisconsin Card-Sorting Task (iWCST) optimized for online assessment of perseveration errors (PE). Predictions of the percentage of PE, PE (%), in non-repetitive versus repetitive situations were derived from the established supervisory attention system (SAS) theory, non-repetitive PE (%) < repetitive PE (%), and the novel goal-directed instrumental control (GIC) theory, non-repetitive PE (%) > repetitive PE (%).

Results

Bayesian t-tests revealed the presence of a robust error suppression effect (ESE) indicating that PE are less likely in repetitive situations than in non-repetitive situations, contradicting SAS theory with posterior model probability p < 0.001 and confirming GIC theory with posterior model probability p > 0.999. We conclude that repetitive situations support cognitive set switching in the iWCST by facilitating the retrieval of goal-directed, instrumental memory that associates stimulus features, actions, and outcomes, thereby generating the ESE in neurotypical individuals. We also report exploratory data analyses, including a Bayesian network analysis of relationships between iWCST measures.

Discussion

Overall, this study serves as a paradigmatic model for combining digital technologies, theory-driven research, and Bayesian statistics in neuropsychology. It also provides insight into how this integrative, innovative approach can advance the understanding of executive function and cognitive flexibility and inform future research and clinical applications.

Exploring behavioural and cognitive dysexecutive syndrome in patients with focal prefrontal cortex damage

This study's objectives were to characterize the frequency and profile of behavioral and cognitive dysexecutive syndromes in patients with focal prefrontal cortex damage and how these syndromes overlap. We also examined the contribution of the prefrontal brain regions to these syndromes. Therefore, thirty patients with prefrontal cortex damage and thirty control subjects were compared on their performances using the GREFEX battery assessing the dysexecutive syndromes. The results showed that combined behavioral and cognitive dysexecutive syndrome was observed in 53.33%, while pure cognitive dysexecutive syndrome was observed in 20% and behavioral in 26.67%. Also, almost all behavioral and cognitive dysexecutive disorders discriminated frontal patients from controls. Moreover, correlations and regression analyses between task scores in both domains of dysexecutive syndromes showed that the spectrum of behavioral disorders was differentially associated with cognitive impairment of initiation, inhibition, generation, deduction, coordination, flexibility and the planning process. Furthermore, the patterns of cognitive and behavioral dysexecutive syndrome were both predictors of impairment in daily living activities and loss of autonomy. Finally, frontal regions contributing to different dysexecutive syndromes assessed by MRI voxel lesion symptom analysis indicate several overlapping regions centered on the ventromedial and dorsomedial prefrontal cortex for both domains of dysexecutive syndrome. This study concludes that damage to the frontal structures may lead to a diverse set of changes in both cognitive and behavioral domains which both contribute to loss of autonomy. The association of the ventromedial and dorsomedial prefrontal regions to both domains of dysexecutive syndrome suggests a higher integrative role of these regions in processing cognition and behavior.

Same, Same but Different? A Multi-Method Review of the Processes Underlying Executive Control

Attention, working memory, and executive control are commonly considered distinct cognitive functions with important reciprocal interactions. Yet, longstanding evidence from lesion studies has demonstrated both overlap and dissociation in their behavioural expression and anatomical underpinnings, suggesting that a lower dimensional framework could be employed to further identify processes supporting goal-directed behaviour. Here, we describe the anatomical and functional correspondence between attention, working memory, and executive control by providing an overview of cognitive models, as well as recent data from lesion studies, invasive and non-invasive multimodal neuroimaging and brain stimulation. We emphasize the benefits of considering converging evidence from multiple methodologies centred on the identification of brain mechanisms supporting goal-driven behaviour. We propose that expanding on this approach should enable the construction of a comprehensive anatomo-functional framework with testable new hypotheses, and aid clinical neuroscience to intervene on impairments of executive functions.

The Role of Neuropsychology in Traumatic Brain Injury: Comprehensive Literature Review

Traumatic brain injury (TBI) is a major public health concern, often leading to significant behavioral and cognitive changes with subsequent impairment in daily functioning and personal interactions. The management of TBI involves a multidisciplinary approach. Neuropsychology has emerged as a critical discipline in assessing, diagnosing, treating, and rehabilitating individuals with TBI. Successful management also requires careful consideration of the patient's cognitive status. Therefore, clinicians must have a comprehensive understanding of the overall clinical picture of the patient at the cognitive and physical level. The primary aim of this research is to explore the role of neuropsychology in TBI management and rehabilitation thoroughly while providing an updated review of the literature. Various neuropsychological assessment tools used to evaluate cognitive functioning in individuals with TBI will be discussed in addition to their validity, reliability, and usefulness in identifying cognitive deficits and developing individualized treatment plans. The findings in this article will have significant implications on the clinical practice of neuropsychology in TBI patients, highlighting the importance of neuropsychological assessment in optimizing the management of this population. The need for increased awareness of neuropsychology among health care professionals, especially in the acute hospital setting, is growing along with the increase in diagnosis of TBI and its complications. Adequate understanding of the complex interplay between cognitive, emotional, and behavioral factors in TBI can inform the development of new interventions and treatment strategies, making it equally as important for patients and their families.

Dopaminergic and norepinephrinergic modulation of endogenous event-related potentials: A systematic review and meta-analysis

Event-related potentials (ERPs) represent the cortical processing of sensory, motor or cognitive functions invoked by particular events or stimuli. A current theory posits that the catecholaminergic neurotransmitters dopamine (DA) and norepinephrine (NE) modulate a number of endogenous ERPs during various cognitive processes. This manuscript aims to evaluate a leading neurotransmitter hypothesis with a systematic overview and meta-analysis of pharmacologic DA and NE manipulation of specific ERPs in healthy subjects during executive function. Specifically, the frontally-distributed P3a, N2, and Ne/ERN (or error-related negativity) are supposedly modulated primarily by DA, whereas the parietally-distributed P3b is thought to be modulated by NE. Based on preceding research, we refer to this distinction between frontally-distributed DA-sensitive and parietally-distributed NE-sensitive ERP components as the Extended Neurobiological Polich (ENP) hypothesis. Our systematic review and meta-analysis indicate that this distinction is too simplistic and many factors interact with DA and NE to influence these specific ERPs. These may include genetic factors, the specific cognitive processes engaged, or elements of study design, i.e. session or sequence effects or data-analysis strategies.

Functional near-infrared spectroscopy is a sensitive marker of neurophysiological deficits on executive function tasks in young adults with a history of child abuse

Previous research has shown the utility of imaging measures of neural activity in identifying deficits in cognitive functioning in individuals with a history of child abuse. The purpose of the present study was to measure differences that may exist between individuals who reported physical, emotional, or sexual abuse as children (n = 37) vs. those who did not (n = 47) using Functional Near Infrared Spectroscopy (fNIRS) during the completion of cognitive tasks of executive function. The results showed a significantly higher rate and number of errors of commission on the Conners CPT test in the child abuse group compared to the control group. The analyses also showed a statistically significant decrease in oxyhemoglobin (oxy-Hb) concentration in the left rostral prefrontal cortex in the child abuse group compared to the no-abuse group during the Wisconsin Card Sorting Test (WCST). A similar, albeit non-significant, trend toward decreased oxy-Hb concentration was observed in the child abuse group in the right dorsolateral prefrontal cortex (dlPFC) on the OSPAN and Connors CPT. The results suggest that the latter group may show subtle neurological deficits that persist into adulthood that may not manifest on traditional measures of cognitive function. These findings have implications for the development of remediation and treatment strategies in this population.

Association of PPP1R1B polymorphisms with working memory in healthy Han Chinese adults

Aims

The dopamine- and cAMP-regulated phosphoprotein (DARPP-32), which is encoded by the PPP1R1B gene, plays a converging regulatory role in the central nervous system by mediating the actions of dopamine, serotonin, and glutamate. Previous studies have demonstrated that variations in genes related to the dopamine system influence working memory. The present study thus investigated whether polymorphisms in PPP1R1B gene were associated with working memory.

Materials and methods

A sample of 124 healthy Han Chinese were genotyped for three single nucleotide polymorphisms of PPP1R1B gene, namely rs12601930C/T, rs879606A/G, and rs3764352A/G, using polymerase chain reaction and restriction fragment length polymorphism analysis. Working memory performance was assessed using the Wisconsin Card Sorting Test (WCST).

Results

Significant differences were observed in the Total Correct (TC), Total Errors (TE), and Conceptual Level Responses (CLR) scores of the WCST among the three rs12601930C/T genotypes (p = 0.044, 0.044, and 0.047, respectively); in TC, TE, Non-Perseverative Errors (NPE), and CLR scores between participants with the CC and (CT + TT) rs12601930C/T polymorphism genotypes (p = 0.032, 0.032, 0.019, and 0.029, respectively); in TC, TE, Perseverative Errors (PE), NPE, and CLR scores between participants with the (CT + CC) and TT rs12601930C/T polymorphism genotypes (p = 0.001, 0.001, 0.011, 0.004, and 0.001, respectively); and in NPE and CLR scores between participants with the GG and (AG + AA) genotypes of the rs3764352A/G polymorphism (p = 0.011 and 0.010). Furthermore, for males only, there were significant differences in TC, TE, PE, NPE, and CLR scores among the rs12601930C/T genotypes (p = 0.020, 0.020, 0.037, 0.029, and 0.014, respectively) and NPE and CLR scores among the rs3764352 genotypes (p = 0.045 and 0.042).

Conclusion

PPP1R1B gene polymorphisms rs12601930C/T and rs3764352A/G might be associated with working memory assessed by the WCST in healthy Chinese adults, especially among males.

Cingulate transcranial direct current stimulation in adults with HIV

BACKGROUND

Neuronal dysfunction plays an important role in the high prevalence of HIV-associated neurocognitive disorders (HAND) in people with HIV (PWH). Transcranial direct current stimulation (tDCS)-with its capability to improve neuronal function-may have the potential to serve as an alternative therapeutic approach for HAND. Brain imaging and neurobehavioral studies provide converging evidence that injury to the anterior cingulate cortex (ACC) is highly prevalent and contributes to HAND in PWH, suggesting that ACC may serve as a potential neuromodulation target for HAND. Here we conducted a randomized, double-blind, placebo-controlled, partial crossover pilot study to test the safety, tolerability, and potential efficacy of anodal tDCS over cingulate cortex in adults with HIV, with a focus on the dorsal ACC (dACC).

METHODS

Eleven PWH (47-69 years old, 2 females, 100% African Americans, disease duration 16-36 years) participated in the study, which had two phases, Phase 1 and Phase 2. During Phase 1, participants were randomized to receive ten sessions of sham (n = 4) or cingulate tDCS (n = 7) over the course of 2-3 weeks. Treatment assignments were unknown to the participants and the technicians. Neuropsychology and MRI data were collected from four additional study visits to assess treatment effects, including one baseline visit (BL, prior to treatment) and three follow-up visits (FU1, FU2, and FU3, approximately 1 week, 3 weeks, and 3 months after treatment, respectively). Treatment assignment was unblinded after FU3. Participants in the sham group repeated the study with open-label cingulate tDCS during Phase 2. Statistical analysis was limited to data from Phase 1.

RESULTS

Compared to sham tDCS, cingulate tDCS led to a decrease in Perseverative Errors in Wisconsin Card Sorting Test (WCST), but not Non-Perseverative Errors, as well as a decrease in the ratio score of Trail Making Test-Part B (TMT-B) to TMT-Part A (TMT-A). Seed-to-voxel analysis with resting state functional MRI data revealed an increase in functional connectivity between the bilateral dACC and a cluster in the right dorsal striatum after cingulate tDCS. There were no differences in self-reported discomfort ratings between sham and cingulate tDCS.

CONCLUSIONS

Cingulate tDCS is safe and well-tolerated in PWH, and may have the potential to improve cognitive performance and brain function. A future study with a larger sample is warranted.

Neuropsychological Profile of College Students Who Engage in Binge Drinking

This study investigated the neuropsychological profile of college students who engage in binge drinking (BD) using comprehensive neuropsychological tests evaluating verbal/non-verbal memory, executive functions, and attention. Groups were determined based on scores on the Korean version of the Alcohol Use Disorder Identification Test (AUDIT-K) and Alcohol Use Questionnaire (AUQ). There were 79 and 81 participants in the BD and non-BD groups, respectively. We administered the Korean version of the California Verbal Learning Test (K-CVLT) and Rey-Osterrieth Complex Figure Test (RCFT) to evaluate verbal and non-verbal memory, respectively, and measured executive functions using the Wisconsin Card Sorting Test (WCST), Trail-Making Test, Controlled Oral Word Association Test and Stroop Color-Word Test. We administered the d2 test to evaluate attention. Neuropsychological performance was analyzed by multivariate analysis of variance. The BD group showed significantly poorer performance in the long-term free recall condition of the K-CVLT and delayed recall condition of the RCFT and completed significantly fewer categories on the WCST than the non-BD group. In addition, there were significant negative associations among the AUDIT-K total score, AUQ binge score, and long-term free recall score of the K-CVLT. There were significant negative associations between the total AUDIT-K score and delayed recall RCFT score, and between the total AUDIT-K total score and numbers of completed categories on the WCST. These results indicate that college students who participate in BD have difficulties with verbal/non-verbal memory and executive functions, and further suggest that excessive alcohol use could have detrimental effects on the hippocampal-prefrontal circuit even with a relatively short period of alcohol use.

Improved Executive Functions and Reduced Craving in Youths with Methamphetamine Addiction: Evidence from Combined Transcranial Direct Current Stimulation with Mindfulness Treatment

OBJECTIVE

Transcranial direct current stimulation (tDCS) and mindfulness practices have been proposed as a potential approach to improve executive functions (EFs) and reduce craving in persons with substance use disorders. Based on the neural mechanisms of action of each of these interventions, the combination of both non-pharmacological interventions might have additive effects. In the current study, the effects of tDCS combined with mindfulness-based substance abuse treatment (MBSAT) to improve EFs and reduce craving were investigated in early abstinent methamphetamine abuse.

METHODS

Eighty (youths aged between 18 and 21) early-abstinent methamphetamine users were randomly assigned to the research groups (tDCS group [n = 20], mindfulness group [n = 20], combined mindfulness-tDCS group [n = 20], and sham group [n = 20]). Active tDCS (1.5 mA,20 min, 12 sessions) or sham tDCS was appliedover the left dorsolateral prefrontal cortex and the MBSAT protocol was used over twelve 50-min sessions.

RESULTS

Both in the post-test phase (immediately after the intervention) and follow-up phase (one month after the intervention), performance in most EFs tasks significantly improved in the combination group which received real tDCS ＋ MBSAT, as compared to baseline values and sham stimulation group. Similarly, a significant reduction in craving was observed after intervention inall treatment groups, but not the sham stimulation group. Interestingly, the increase in EFs and the reduction in craving post versus pre tDCS ＋ MBSAT intervention were correlated.

CONCLUSION

Findings from the current study provide initial support for the clinical effectiveness of combination tDCS ＋ MBSAT, possibly influencing cognitive/affective processes.

A network analysis and empirical validation of executive deficits in patients with psychosis and their healthy siblings

BACKGROUND

Psychopathological symptoms and cognitive impairment are core features of patients with psychotic disorders. Executive dysfunctions are commonly observed and typically assessed using tests like the Wisconsin Card Sorting Test (WCST). However, the structure of executive deficits remains unclear, and the underlying processes may be different. This study aimed to explore and compare the network structure of WCST measures in patients with psychosis and their unaffected siblings and to empirically validate the resulting network structure of the patients.

METHODS

The subjects were 298 patients with a DSM 5 diagnosis of a psychotic disorder and 89 of their healthy siblings. The dimensionality and network structure of the WCST were examined by means of exploratory graph analysis (EGA) and network centrality parameters.

RESULTS

The WCST network structure comprised 4 dimensions: perseveration (PER), inefficient sorting (IS), failure to maintain set (FMS) and learning (LNG). The patient and sibling groups showed a similar network structure, which was reliably estimated. PER and IS showed common and strong associations with antecedent, concurrent and outcome validators. The LNG dimension was also moderately associated with these validators, but FMS did not show significant associations.

CONCLUSIONS

Four cognitive processes underlying WCST performance were identified by the network analysis. PER, IS and LNG were associated with and shared common antecedent, concurrent and outcome validators, while FMS was not associated with external validators. These four underlying dysfunctions might help disentangle the neurofunctional basis of executive deficits in psychosis.

A Predictive Processing Account of Card Sorting: Fast Proactive and Reactive Frontoparietal Cortical Dynamics during Inference and Learning of Perceptual Categories

For decades, a common assumption in cognitive neuroscience has been that prefrontal executive control is mainly engaged during target detection [Posner, M. I., & Petersen, S. E. The attention system of the human brain. Annual Review of Neuroscience, 13, 25-42, 1990]. More recently, predictive processing theories of frontal function under the Bayesian brain hypothesis emphasize a key role of proactive control for anticipatory action selection (i.e., planning as active inference). Here, we review evidence of fast and widespread EEG and magnetoencephalographic fronto-temporo-parietal cortical activations elicited by feedback cues and target cards in the Wisconsin Card Sorting Test. This evidence is best interpreted when considering negative and positive feedback as predictive cues (i.e., sensory outcomes) for proactively updating beliefs about unknown perceptual categories. Such predictive cues inform posterior beliefs about high-level hidden categories governing subsequent response selection at target onset. Quite remarkably, these new views concur with Don Stuss' early findings concerning two broad classes of P300 cortical responses evoked by feedback cues and target cards in a computerized Wisconsin Card Sorting Test analogue. Stuss' discussion of those P300 responses-in terms of the resolution of uncertainty about response (policy) selection as well as the participants' expectancies for future perceptual or motor activities and their timing-was prescient of current predictive processing and active (Bayesian) inference theories. From these new premises, a domain-general frontoparietal cortical network is rapidly engaged during two temporarily distinct stages of inference and learning of perceptual categories that underwrite goal-directed card sorting behavior, and they each engage prefrontal executive functions in fundamentally distinct ways.

The effect of physical activity with and without cognitive demand on the improvement of executive functions and behavioral symptoms in children with ADHD

Background: Purposeful physical activities improve cognitive functions. Two possible mechanisms are available for this intervention including the impact of the physical component of exercise and goal-directedness as a cognitive component. In the present study, we aimed to compare the effect of physical activity with and without cognitive demand on executive functions and behavioral symptoms in children with ADHD.Methods: Thirty children with ADHD were randomly assigned to two equal groups of physical activity training with and without cognitive demand. Exercise for cognitive improvement and rehabilitation (EXCIR) or running, as an aerobic exercise, were used for intervention in two groups. Executive functions and ADHD symptoms were measured in three sessions including baseline, post-intervention, and follow-up assessments, using 1-back, Wisconsin Card Sorting, and Go/No-Go tests and Conner's Teacher and Parent Rating scales. Repeated measures ANOVAs were used for analysis.Results: The results showed physical activity with cognitive demand, compared to the physical activity without cognitive demand, has a better and longer impact on the improvement of executive functions and ADHD symptoms.Conclusions: Cognitive rehabilitation with combined physical and cognitive tasks has a beneficial and lasting impact on impaired executive functions and behavioral symptoms in children with ADHD.

Maternal adverse childhood experiences, executive function & emotional availability in mother-child dyads

BACKGROUND

Maternal adverse childhood experiences (ACEs) are associated with difficulties in parent-child relationships; however, current research has primarily used cross-sectional designs. Parent and child behavior may be differentially affected by ACEs as children develop and caregiving demands change. Furthermore, diminished executive function (EF) is associated with both ACEs and parenting difficulties and may be a mechanism underlying the intergenerational effects of ACEs.

OBJECTIVE

This study examined longitudinal associations between maternal ACEs, maternal EF, and patterns of change in maternal and child emotional availability (EA).

PARTICIPANTS

Mother-child dyads (N = 114) participated in five assessments over a 5-year period.

METHODS

Maternal ACEs were measured retrospectively at 3 months, maternal EF was assessed at 8 months, and mother-child interactions were videotaped at 18, 36 and 60 months postpartum. Multilevel modelling was used to model growth curves.

RESULTS

Maternal EA did not significantly change, while child EA increased from 18 to 60 months postpartum. Maternal ACEs were negatively associated with maternal and child EA at 18 months postpartum; this effect was not significant at 60 months postpartum. In contrast, there was a persistent, positive effect of maternal EF on EA trajectories. Maternal EF did not mediate the association between ACEs and EA. There were also significant within-dyad associations between maternal and child EA.

CONCLUSIONS

The effects of maternal ACEs on parenting are not necessarily persistent. Findings also support sustained relations between maternal EF and mother-child interactions across early childhood, suggesting the utility of EF as an intervention target.

The Reliability of the Wisconsin Card Sorting Test in Clinical Practice

The Wisconsin Card Sorting Test (WCST) represents the gold standard for the neuropsychological assessment of executive function. However, very little is known about its reliability. In the current study, 146 neurological inpatients received the Modified WCST (M-WCST). Four basic measures (number of correct sorts, categories, perseverative errors, set-loss errors) and their composites were evaluated for split-half reliability. The reliability estimates of the number of correct sorts, categories, and perseverative errors fell into the desirable range (rel ≥ .90). The study therefore disclosed sufficiently reliable M-WCST measures, fostering the application of this eminent psychological test to neuropsychological assessment. Our data also revealed that the M-WCST possesses substantially better psychometric properties than would be expected from previous studies of WCST test-retest reliabilities obtained from non-patient samples. Our study of split-half reliabilities from discretionary construed and from randomly built M-WCST splits exemplifies a novel approach to the psychometric foundation of neuropsychology.

Toward a Computational Neuropsychology of Cognitive Flexibility

Cognitive inflexibility is a well-documented, yet non-specific corollary of many neurological diseases. Computational modeling of covert cognitive processes supporting cognitive flexibility may provide progress toward nosologically specific aspects of cognitive inflexibility. We review computational models of the Wisconsin Card Sorting Test (WCST), which represents a gold standard for the clinical assessment of cognitive flexibility. A parallel reinforcement-learning (RL) model provides the best conceptualization of individual trial-by-trial WCST responses among all models considered. Clinical applications of the parallel RL model suggest that patients with Parkinson's disease (PD) and patients with amyotrophic lateral sclerosis (ALS) share a non-specific covert cognitive symptom: bradyphrenia. Impaired stimulus-response learning appears to occur specifically in patients with PD, whereas haphazard responding seems to occur specifically in patients with ALS. Computational modeling hence possesses the potential to reveal nosologically specific profiles of covert cognitive symptoms, which remain undetectable by traditionally applied behavioral methods. The present review exemplifies how computational neuropsychology may advance the assessment of cognitive flexibility. We discuss implications for neuropsychological assessment and directions for future research.

Parallel model-based and model-free reinforcement learning for card sorting performance

The Wisconsin Card Sorting Test (WCST) is considered a gold standard for the assessment of cognitive flexibility. On the WCST, repeating a sorting category following negative feedback is typically treated as indicating reduced cognitive flexibility. Therefore such responses are referred to as 'perseveration' errors. Recent research suggests that the propensity for perseveration errors is modulated by response demands: They occur less frequently when their commitment repeats the previously executed response. Here, we propose parallel reinforcement-learning models of card sorting performance, which assume that card sorting performance can be conceptualized as resulting from model-free reinforcement learning at the level of responses that occurs in parallel with model-based reinforcement learning at the categorical level. We compared parallel reinforcement-learning models with purely model-based reinforcement learning, and with the state-of-the-art attentional-updating model. We analyzed data from 375 participants who completed a computerized WCST. Parallel reinforcement-learning models showed best predictive accuracies for the majority of participants. Only parallel reinforcement-learning models accounted for the modulation of perseveration propensity by response demands. In conclusion, parallel reinforcement-learning models provide a new theoretical perspective on card sorting and it offers a suitable framework for discerning individual differences in latent processes that subserve behavioral flexibility.

A Computational Study of Executive Dysfunction in Amyotrophic Lateral Sclerosis

Executive dysfunction is a well-documented, yet nonspecific corollary of various neurological diseases and psychiatric disorders. Here, we applied computational modeling of latent cognition for executive control in amyotrophic lateral sclerosis (ALS) patients. We utilized a parallel reinforcement learning model of trial-by-trial Wisconsin Card Sorting Test (WCST) behavior. Eighteen ALS patients and 21 matched healthy control participants were assessed on a computerized variant of the WCST (cWCST). ALS patients showed latent cognitive symptoms, which can be characterized as bradyphrenia and haphazard responding. A comparison with results from a recent computational Parkinson's disease (PD) study (Steinke et al., 2020, J Clin Med) suggests that bradyphrenia represents a disease-nonspecific latent cognitive symptom of ALS and PD patients alike. Haphazard responding seems to be a disease-specific latent cognitive symptom of ALS, whereas impaired stimulus-response learning seems to be a disease-specific latent cognitive symptom of PD. These data were obtained from the careful modeling of trial-by-trial behavior on the cWCST, and they suggest that computational cognitive neuropsychology provides nosologically specific indicators of latent facets of executive dysfunction in ALS (and PD) patients, which remain undiscoverable for traditional behavioral cognitive neuropsychology. We discuss implications for neuropsychological assessment, and we discuss opportunities for confirmatory computational brain imaging studies.

Rethinking Executive Function and Its Development

Research on executive function in early childhood has flourished in recent years. Much of this work is premised on a view of development of executive function as the emergence of a set of domain-general component processes (e.g., working memory updating, inhibitory control, shifting). This view has shaped how we think about relations between executive function and other aspects of development, the role of the environment in executive-function development, and how best to improve executive function in children who struggle with it. However, there are conceptual and empirical reasons to doubt that executive function should be defined in this way. I argue that the development of executive function is better understood as the emergence of skills in using control in the service of specific goals. Such goals activate and are influenced by mental content such as knowledge, beliefs, norms, values, and preferences that are acquired with development and are important to consider in understanding children’s performance on measures of executive function. This account better explains empirical findings than the component-process view; leads to specific, testable hypotheses; and has implications for theory, measurement, and interventions.

Computational Modeling for Neuropsychological Assessment of Bradyphrenia in Parkinson's Disease

The neural mechanisms of cognitive dysfunctions in neurological diseases remain poorly understood. Here, we conjecture that this unsatisfying state-of-the-art is in part due to the non-specificity of the typical behavioral indicators for cognitive dysfunctions. Our study addresses the topic by advancing the assessment of cognitive dysfunctions through computational modeling. We investigate bradyphrenia in Parkinson's disease (PD) as an exemplary case of cognitive dysfunctions in neurological diseases. Our computational model conceptualizes trial-by-trial behavioral data as resulting from parallel cognitive and sensorimotor reinforcement learning. We assessed PD patients 'on' and 'off' their dopaminergic medication and matched healthy control (HC) participants on a computerized version of the Wisconsin Card Sorting Test. PD patients showed increased retention of learned cognitive information and decreased retention of learned sensorimotor information from previous trials in comparison to HC participants. Systemic dopamine replacement therapy did not remedy these cognitive dysfunctions in PD patients but incurred non-desirable side effects such as decreasing cognitive learning from positive feedback. Our results reveal novel insights into facets of bradyphrenia that are indiscernible by observable behavioral indicators of cognitive dysfunctions. We discuss how computational modeling may contribute to the advancement of future research on brain-behavior relationships and neuropsychological assessment.

Risky decision making and cognitive flexibility among online sports bettors in Nigeria

Online sports betting is a popular recreational activity in Nigeria. Like other forms of gambling, risk of pathological progression exists for gamblers who continue betting despite severe financial and psychosocial consequences. In the present study, we examined whether this population of gamblers shows deficits in decision making and cognitive flexibility that have been documented in Western gambling populations. Thirty‐six online sports bettors and 42 non‐gambling participants completed a version of the Iowa gambling task (IGT) and an established set‐shifting task for the assessment of cognitive flexibility. The two groups did not differ significantly in the selection of disadvantageous decks on the IGT. In contrast, sports bettors committed significantly more errors on the set‐shifting task than non‐gambling control participants. As this performance deficit was not specific to trials requiring a set shift, it most likely resulted from gambling‐related changes in general cognitive or motivational abilities that are required to successfully complete challenging mental tasks. While our results illustrate that findings from Western populations cannot automatically be generalised to other contexts, it should be noted that we focused on only one particular type of gambling and included mostly participants with mild gambling‐related problems.

The medial prefrontal cortex is needed for resolving interference even when there are no changes in task rules and strategies

The prefrontal cortex (PFC) plays a key role in behavioral flexibility, and the ability to resolve conflict from shifting strategies, task rules or attentional demands seems to be a hallmark of PFC function. Conflict also occurs in the domain of memory and the PFC plays an important role in the ability to cope with interference between competing retrieval targets. Previous studies often involved both interference and changes in task demands, which makes it difficult to determine the degree to which mnemonic interference per se engages PFC processing. We trained rats on a continuous matching to sample task in two conditions that varied in terms of the amount of interference present but not the task demands and found that temporary inactivation of the medial PFC caused a greater impairment in the high-interference condition. This result suggests that the PFC plays an important role in resolving interference which can be distinguished from its role in shifting task demands. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Are Difficult-To-Study Populations too Difficult to Study in a Reliable Way?

Abstract. Replication studies, pre-registration, and increases in statistical power will likely improve the reliability of scientific evidence. However, these measures face critical limitations in populations that are inherently difficult to study. Members of difficult-to-study populations (e.g., patients, children, non-human animals) are less accessible to researchers, which typically results in small-sample studies that are infeasible to replicate. Nevertheless, meta-analyses on clinical neuropsychological data suggest that difficult-to-study populations can be studied in a reliable way. These analyses often produce unbiased effect-size estimates despite aggregating across severely underpowered original studies. This finding can be attributed to a neuropsychological research culture involving the non-selective reporting of results from standardized and validated test procedures. Consensus guidelines, test manuals, and psychometric evidence constrain the methodological choices made by neuropsychologists, who regularly report the results from neuropsychological test batteries irrespective of their statistical significance or novelty. Comparable shifts toward more standardization and validation, complete result reports, and between-lab collaborations can allow for a meaningful and reliable study of psychological phenomena in other difficult-to-study populations.

A Meta-Analysis of Relationships between Measures of Wisconsin Card Sorting and Intelligence

The Wisconsin Card Sorting Test (WCST) represents a widely utilized neuropsychological assessment technique for executive function. This meta-analysis examined the discriminant validity of the WCST for the assessment of mental shifting, considered as an essential subcomponent of executive functioning, against traditional psychometric intelligence tests. A systematic search was conducted, resulting in 72 neuropsychological samples for the meta-analysis of relationships between WCST scores and a variety of intelligence quotient (IQ) domains. The study revealed low to medium-sized correlations with IQ domains across all WCST scores that could be investigated. Verbal/crystallized IQ and performance/fluid IQ were indistinguishably associated with WCST scores. To conclude, the WCST assesses cognitive functions that might be partially separable from common conceptualizations of intelligence. More vigorous initiatives to validate putative indicators of executive function against intelligence are required.

A Dynamic Framework for Modelling Set-Shifting Performances

Higher-order cognitive functions can be seen as a class of cognitive processes which are crucial in situations requiring a flexible adjustment of behaviour in response to changing demands of the environment. The cognitive assessment of these functions often relies on tasks which admit a dynamic, or longitudinal, component requiring participants to flexibly adapt their behaviour during the unfolding of the task. An intriguing feature of such experimental protocols is that they allow the performance of an individual to change as the task unfolds. In this work, we propose a Latent Markov Model approach to capture some dynamic aspects of observed response patterns of both healthy and substance dependent individuals in a set-shifting task. In particular, data from a Wisconsin Card Sorting Test were analysed in order to represent performance trends in terms of latent cognitive states dynamics. The results highlighted how a dynamic modelling approach can considerably improve the amount of information a researcher, or a clinician, can obtain from the analysis of a set-shifting task.

Depression, apathy and impaired self-awareness following severe traumatic brain injury: a preliminary investigation

Primary Objective: The primary aim of this study was to determine the frequency of severe impaired self-awareness (ISA) in patients with severe traumatic brain injury (TBI) and the correlates of selected clinical, neuropsychiatric and cognitive variables. The secondary aim of the study was to assess depression and apathy on the basis of their level of self-awareness. Methods: Thirty patients with severe TBI and 30 demographically matched healthy control subjects (HCs) were compared on measures of ISA, depression, anxiety, alexithymia, neuropsychiatric symptoms and cognitive flexibility. Results: Twenty percent of the patients demonstrated severe ISA. Severe post-acute ISA was associated with more severe cognitive inflexibility, despite the absence of differences in TBI severity, as evidenced by a Glasgow Coma Scale (GCS) score lower than 9 in all cases in the acute phase. Patients with severe ISA showed lower levels of depression and anxiety but tended to show more apathy and to have greater difficulty describing their emotional state than patients with severe TBI who showed minimal or no disturbance in self-awareness. Conclusion: These findings support the general hypothesis that severe ISA following severe TBI is typically not associated with depression and anxiety, but rather with apathy and cognitive inflexibility.

Multiple Levels of Control Processes for Wisconsin Card Sorts: An Observational Study

We explored short-term behavioral plasticity on the Modified Wisconsin Card Sorting Test (M-WCST) by deriving novel error metrics by stratifying traditional set loss and perseverative errors. Separating the rule set and the response set allowed for the measurement of performance across four trial types, crossing rule set (i.e., maintain vs. switch) and response demand (i.e., repeat vs. alternate). Critically, these four trial types can be grouped based on trial-wise feedback on t − 1 trials. Rewarded (correct) maintain t − 1 trials should lead to error enhancement when the response demands shift from repeat to alternate. In contrast, punished (incorrect) t − 1 trials should lead to error suppression when the response demands shift from repeat to alternate. The results supported the error suppression prediction: An error suppression effect (ESE) was observed across numerous patient samples. Exploratory analyses show that the ESE did not share substantial portions of variance with traditional neuropsychological measures of executive functioning. They further point into the direction that striatal or limbic circuit neuropathology may be associated with enhanced ESE. These data suggest that punishment of the recently executed response induces behavioral avoidance, which is detectable as the ESE on the WCST. The assessment of the ESE might provide an index of response-related avoidance learning on the WCST.

Validity of the Verbal Concept Attainment Test in multiple sclerosis

OBJECTIVE

As many as 70% of people with multiple sclerosis (MS) have clinically significant cognitive impairment, and most of these individuals exhibit executive dysfunction. Most research concerning executive dysfunction in MS has focused upon nonverbal measures. The Verbal Concept Attainment Test (VCAT) has demonstrated construct validity as an executive function measure in people infected with HIV and in people with focal brain lesions, but its validity among people with MS is unknown. The current study evaluated the VCAT's criterion, diagnostic, and ecological validity in people with MS.

METHOD

A comprehensive neuropsychological battery was administered to 44 healthy individuals and 97 people with MS. Based on existing norms, they were classified as impaired or unimpaired, resulting in 65 people with MS categorized as unimpaired and 32 as impaired. They were administered a battery assessing neuropsychological impairment and disability status.

RESULTS

The VCAT correlated with most measures of neuropsychological function, but its largest correlations occurred with measures of executive function, working memory, and verbal memory. Regarding classification accuracy, the VCAT achieved satisfactory sensitivity and specificity in identifying neuropsychological impairment in people with MS. The VCAT achieved moderate correlations with measures of disability status.

CONCLUSIONS

The data provide evidence for an optimal VCAT cutoff score for establishing neuropsychological impairment in people with MS, and they demonstrate that the VCAT possesses acceptable criterion, diagnostic, and ecological validity. As such, these data support the inclusion of the VCAT in research and clinical practice involving people with MS.

The Causal Role of Right Frontopolar Cortex in Moral Judgment, Negative Emotion Induction, and Executive Control

Introduction:

Converging evidence suggests that both emotional and cognitive processes are critically involved in moral judgment, and may be mediated by discrete parts of the prefrontal cortex. The current study aimed at investigating the mediatory effect of right Frontopolar Cortex (rFPC) on the way that emotions affect moral judgments.

Methods:

Six adult patients affected by rFPC and 10 healthy controls were included in the study. Participants made judgements on moral dilemmas after being shown either neutral or emotional pictures. The role of rFPC in executive control and emotional experience was also examined.

Results:

The study results showed that inducing an emotional state increased the number of utilitarian responses both in the patients and controls. However, no significant differences were observed between the patients and controls in response time or the number of utilitarian responses. Also, no significant differences were observed in personal and impersonal dilemmas before and after the emotion induction in intergroup comparisons. Results of the executive control tasks showed reduced performance in patients affected by rFPC compared with the controls.

Conclusion:

The results of the current study suggested that rFPC might not have a direct role in mediating emotional processes during moral judgments, but possibly this region is important in a network supporting executive control functions.

Differential executive functioning in young adulthood as a function of experienced child abuse

INTRODUCTION

Previous research has shown cognitive dysfunction in adults with a history of child abuse. The purpose of the present study was to measure differences that exist in executive functioning skills between individuals who have been abused as children versus those without the history of childhood abuse.

METHODS

The present study recruited 43 students from the University of North Dakota (33 women) between ages 18 and 23 years of age. The participants were administered several prescreening measures, including a measure of physical child abuse, emotional child abuse, and sexual child abuse. Based on responses to these measures, participants were grouped into a no-child-abuse group, a mild-child-abuse group, or a moderate-to-severe child abuse group. All participants were administered measures of executive functioning that included the Wisconsin Card Sorting Task, the Operation Span Task, and the Connors Continuous Performance Task with a simultaneous recording of electroencephalographic activity using a wireless 9 channel EEG system.

RESULTS

There was a statistically significant main effect of child abuse group (no child abuse vs. moderate-to-high child abuse) for the EEG-derived probability of cognitive workload during the OSPAN. Beta bandwidths for individuals in the drug abuse group, which served as a covariate, were also found to be significantly attenuated during the Connors CPT.

CONCLUSION

Individuals that have been abused as children must use significantly more mental effort to complete executive functioning tasks as compared to their non-abused counterparts. Increased neurological effort could be used to explain poor decision-making skills that are common within the population.

Stimulus- and response-based interference contributes to the costs of switching between cognitive tasks

Little is known about how stimulus- and response-based interference might interact to contribute to the costs of switching between cognitive tasks. We analyzed switch costs in a novel cued task-switching/card-matching paradigm in a large study (N = 95). We reasoned that interference from previously active task sets may be contingent upon the retrieval of these task sets via stimulus processing, or alternatively, via response processing. We examined the efficacy of these two factors through eligibility manipulations. That is, stimulus/response features that were capable of retrieving task sets from the previous trial remained eligible (or not) on the current trial. We report three main findings: first, no switch costs were found when neither stimulus features, nor response features, were adequate for the retrieval of the previously executed task sets. Second, we found substantial switch costs when, on switch trials, stimulus features kept the previously executed task eligible, and we found roughly equivalent switch costs when the previously executed response remained eligible. Third, evidence for stimulus-induced switch costs was exclusively observed when previously executed responses remained ineligible. These data indicate that stimulus-based interference, and of importance, response-based interference, contribute comparably to switch costs. Possible interpretations of non-additive switch costs are discussed.

Effects of rule uncertainty on cognitive flexibility in a card-sorting paradigm

Cognitive flexibility has been studied in two separate research traditions. Neuropsychologists typically rely on rather complex assessment tools such as the Wisconsin Card Sorting Test (WCST). In contrast, task-switching paradigms are used in experimental psychology to obtain more specific measures of cognitive flexibility. We aim to contribute to the integration of these research traditions by examining the role of the key factor that differs between the WCST and experimental task-switching paradigms: rule uncertainty. In two experimental studies, we manipulated the degree of rule uncertainty after rule switches in a computerized version of the WCST. Across a variety of task parameters, reducing rule uncertainty consistently impaired the speed and accuracy of responses when the rule designated to be more likely turned out to be incorrect. Other performance measures such as the number of perseverative errors were not significantly affected by rule uncertainty. We conclude that a fine-grained analysis of WCST performance can dissociate behavioural indicators that are affected vs. unaffected by rule uncertainty. By this means, it is possible to integrate WCST results and findings obtained from task-switching paradigms that do not involve rule uncertainty.

Cognitive and behavioural dispositions in offspring at high risk for alcoholism

OBJECTIVES

Offspring with family history of alcoholism are considered to be at high risk for alcoholism. The present study sought to expand our understanding of cognitive and behavioural dispositions associated with executive control and self-regulation in alcohol naïve offspring with and without family history of alcoholism.

METHODS

Sample comprised of alcohol naive offspring in two groups: (i) at high risk (n = 34) and (ii) at low risk for alcoholism (n = 34). Both groups were matched on age (+/-1 year), education (+/-1 year) and gender. Measures used were: Mini-International Neuropsychiatric Interview, Family Interview for Genetic Studies, Socio-demographic Data Sheet, Annett's Handedness Questionnaire, Barratt's Impulsiveness Scale-version 11, Digit Span Test, Spatial Span Test, Tower of London, Wisconsin Card Sorting Test, Iowa Gambling Task (IGT) and Game of Dice Task (GDT).

RESULTS

Results showed that alcohol naive offspring at high risk for alcoholism reported significantly high impulsivity and demonstrated significant differences on executive functions and decision making tasks. Correlation analysis revealed that high impulsivity was significantly associated with poor performance on explicit decision making task (GDT) and executive function task (WCST). There was no significant correlation between two decision making tasks (IGT and GDT) in both groups and performance on IGT was not significantly associated with impulsivity and executive functions.

CONCLUSIONS

The present study indicates cognitive and behavioural dispositions in alcohol naive offspring at high risk for alcoholism and support the sub-optimal balance between reflective and impulsive system responsible for addiction. Furthermore, present study supports separability between two different types of decision making tasks.

Cognitive Function and Serum Hormone Levels Are Associated with Gray Matter Volume Decline in Female Patients with Prolactinomas

Background and objective

Cognitive impairments have been reported in patients with hyperprolactinemia; however, there is a lack of knowledge of brain structure alterations relevant to hyperprolactinemia in prolactinomas. Thus, we aimed to identify changes in brain structure in prolactinomas and to determine whether these changes are related to cognitive performance and clinical characteristics.

Methods

Participants were 32 female patients with prolactinomas and 26 healthy controls (HC) matched for age, sex, education, and handedness. All participants underwent magnetic resonance imaging brain scans, neuropsychological assessments, and clinical evaluations. Voxel-based morphometry analysis was used to identify changes in gray matter volume (GMV). Partial correlation analysis and multiple linear regression were performed to determine the relationship between GMV, cognition, and clinical characteristics.

Results

Compared to HC, patients with prolactinomas demonstrated a decrease in GMV in the left hippocampus, left orbitofrontal cortex, right middle frontal cortex (MFC), and right inferior frontal cortex (IFC). In addition, patients performed worse than controls on tests for verbal memory and executive function, and this was significantly related to the GMV of the left hippocampus and right MFC, respectively. Moreover, in the patients, we found a negative relationship between serum prolactin levels and the GMV of the left hippocampus and right IFC, whereas a positive relationship was found between the GMV of the left hippocampus and serum levels of estradiol and luteinizing hormone.

Conclusion

In patients with prolactinomas, specific brain structure abnormalities have been identified and are associated with cognitive impairments and dysfunctional hormones. This study enhances our understanding of brain structure changes that may occur with prolactinomas and provides novel and fundamental evidence for previous behavioral findings relevant to hyperprolactinemia.

Executive control network connectivity strength protects against relapse to cocaine use

Cocaine addiction is characterized by notoriously high relapse rates following treatment. Recent efforts to address poor treatment outcomes have turned to potential neural markers of relapse risk. Accordingly, the present study examined resting state functional connectivity (rsFC) within and between three large-scale cortical networks: the default mode network (DMN), salience network (SN) and executive control network (ECN). All three have been implicated in relapse-related phenomena including craving, withdrawal and executive control deficits. Forty-five cocaine-dependent individuals and 22 healthy controls completed 6-min resting fMRI scans, The Wisconsin Card Sorting Task, Continuous Performance Test and Cocaine Craving Questionnaire. Cocaine-dependent individuals completed all measures in the final week of a residential treatment episode. Ten control and 9 abstinent cocaine-dependent individuals returned for 3-6 month follow-up scan visits. A group-level independent component analysis was employed to generate ECN, DMN and SN components. For individuals abstinent up to day 30 post-treatment (n = 21), we found enhanced pre-discharge rsFC between the left ECN and both the right ECN and SN as well as between the right ECN and left ECN. Left ECN rsFC effects remained elevated 3-6 months later among abstinent cocaine-dependent individuals. Relapse was related to fewer years of education and more years smoking but no other demographic, clinical, treatment and neurocognitive characteristics. Findings suggest that interhemispheric ECN and ECN-SN connectivity strength may protect against relapse to cocaine use following treatment. These patterns of enhanced interhemispheric network connectivity may reflect a greater capacity to engage executive control processes when faced with opportunities to use cocaine post-treatment.

Cognitive flexibility in neurological disorders: Cognitive components and event-related potentials

Performance deficits on the Wisconsin Card Sorting Test (WCST) in patients with prefrontal cortex (PFC) lesions are traditionally interpreted as evidence for a role of the PFC in cognitive flexibility. However, WCST deficits do not occur exclusively after PFC lesions, but also in various neurological and psychiatric disorders. We propose a multi-component approach that can accommodate this pattern of omnipresent WCST deficits: the WCST is not a pure test of cognitive flexibility, but relies on the effective functioning of multiple dissociable cognitive components. Our review of recent efforts to decompose WCST performance deficits supports this view by revealing that WCST deficits in different neurological disorders can be attributed to alterations in different components. Frontoparietal changes underlying impaired set shifting seem to give rise to WCST deficits in patients with amyotrophic lateral sclerosis, whereas the WCST deficits associated with primary dystonia and Parkinson's disease are rather related to frontostriatal changes underlying deficient rule inference. Clinical implications of these findings and of a multi-component view of WCST performance are discussed.

Cognitive flexibility and its electrophysiological correlates in Gilles de la Tourette syndrome

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Gilles de la Tourette syndrome (GTS) may involve cognitive inflexibility.

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A meta-analysis reveals GTS-related deficits on the Wisconsin Card Sorting Test.

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Card-sorting deficits are larger in children than in adults with GTS.

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Adults with GTS show electrophysiological signs of enhanced cognitive control.

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This change may underlie the normalization of cognitive flexibility in adult GTS.

Motor symptoms in Gilles de la Tourette syndrome (GTS) have been related to changes in frontostriatal brain networks. These changes may also give rise to alterations in cognitive flexibility. However, conclusive evidence for altered cognitive flexibility in patients with GTS is still lacking. Here, we meta-analyzed data from 20 neuropsychological studies that investigated cognitive flexibility in GTS using the Wisconsin Card Sorting Test (WCST). Results revealed medium-sized GTS-related performance deficits, which were significantly modulated by age: Whilst being substantial in children and adolescents with GTS, WCST deficits seem to dissolve in adult patients with GTS. This age-related normalization of WCST performance might result from the compensatory recruitment of cognitive control in adult patients with GTS. We addressed this possibility by examining neural correlates of proactive and reactive cognitive control in an event-related potential (ERP) study. We analyzed cue- and target-locked ERPs from 23 adult patients with GTS and 26 matched controls who completed a computerized version of the WCST. Compared to controls, patients with GTS showed a marked increase in parietal cue-locked P3 activity, indicating enhanced proactive cognitive control. We conclude that the additional recruitment of proactive cognitive control might ensure flexible cognitive functioning in adult patients with GTS.

Neurocognitive dysfunction in addiction: Testing hypotheses of diffuse versus selective phenotypic dysfunction with a classification-based approach

Neurocognitive dysfunctions are frequently identified in the addictions. These dysfunctions may indicate either diffuse dysfunction or may represent separate facets that have differential importance to the addiction phenotype. In a sample (n = 260) of alcohol and/or stimulant users and controls we measured responses across 7 diverse neurocognitive measures. These measures were Continuous Performance, Delay Discounting, Iowa Gambling, Stroop, Tower, Wisconsin Card Sorting, and Letter Number Sequencing. Comparisons were then made between the drug-dependent groups and controls using analysis of variance and also using a machine learning approach to classify participants based on task performance as substance-dependent or controls in 1 tree and as alcohol and/or stimulant users or controls in a second tree. The analysis of variance showed significant differences between groups on the Delay Discounting (p < .001), Iowa Gambling (p < .001), Letter Number Sequencing (p < .001), and Wisconsin Card Sorting (p < .05) tasks. The first classification tree correctly classified between substance-dependent or controls for 88.3% of participants and classified between alcohol and/or stimulant users or controls for 63.9% of participants. Delay discounting was the first split in both trees and in the substance-dependent and control tree. The analysis of variance results largely replicate previous findings. The machine learning classification tree analysis provides evidence to support the hypothesis that different measures of neurocognitive dysfunction represent different processes. Among them, delay discounting was the most robust in categorizing drug dependence. (PsycINFO Database Record