Specific Executive Dysfunction Research Articles

Investigating the relationship between specific executive functions and functional decline among community-dwelling older adults: results from a prospective pilot study

BackgroundAs cognitive functions and, more specifically, executive functions (EF) seem to influence autonomy among the elderly, we investigated the role of each of the five EF sub-components (inhibition, spontaneous flexibility, reactive flexibility, planning, and updating in working memory) for the risk of functional decline.MethodA total of 137 community-dwelling participants over 75 years of age were included in a prospective cohort study and assigned to three groups: individuals with neuro-degenerative cognitive disorders, those having cognitive disorders with non-degenerative aetiology, and a control group without any cognitive problems. We measured each EF sub-component and assessed functional decline by evaluating basic (b-ADL) and instrumental activities of daily living (i-ADL) at baseline and 6 months later. We conducted three separate multiple logistic regression models to examine the extent to which the five EF facets predicted overall functional decline at the end of the follow-up period.ResultsWe found that people who exhibited a decline in b-ADLs or/and i-ADLs over 6 months had worse performance on inhibition and two flexibility tasks than those who did not experience a decline. The results suggest that decliners have more difficulties in managing unforeseen events. Inhibition and updating in working memory predicted a decline in b-ADL while spontaneous and reactive flexibilities predicted a decline in i-ADL.ConclusionIn our sample, specific executive dysfunctions were associated with a decline in functional status. With respect to the risk of decline in b-ADL, deficits in inhibition may represent a risk factor, as it regulates over-learned activities. Bothtypes of flexibility, which allow the shifting and generating of adaptive responses, predicted decline in i-ADL. In sum, paying more attention to particular EF profiles would help clinicians to anticipate some aspects of functional decline.

Severity of anabolic steroid dependence, executive function, and personality traits in substance use disorder patients in Norway

IntroductionAnabolic androgenic steroids (AAS), including testosterone and synthetic derivatives, are typically used to increase muscle mass. Many users develop a dependence on these substances, contributing to worsened physical and mental health outcomes. Aspects of personality and executive dysfunction may represent underlying vulnerabilities for developing dependence. ObjectiveTo identify levels of AAS dependence within substance use disorder (SUD) treatment patients and assess the relationship between dependence severity and personality traits and executive function (EF). MethodsData were collected from patients at 38 SUD treatment facilities in Norway. Questionnaires were completed for measures of personality and EF. Measures of symptoms of AAS dependence were used in latent class analysis to identify sub-groups of patients, which were evaluated for association with EF and personality traits, and compared with a group of non-AAS using SUD patients. ResultsThree classes were identified; largely reflecting low, moderate, and high symptoms of dependence. Multinomial regression analyses indicated that moderate and high symptoms were associated with several measures of EF and personality traits, particularly self-monitoring, antagonism, disinhibition, and rigid perfectionism while users with low symptoms exhibited higher capacities for emotional control and shift, and lower negative affectivity, relative to non-AAS using SUD patients. Backward stepwise regressions indicated antagonism, and decreased self-monitoring as key personality and cognitive characteristics of SUD patients with severe AAS dependence. ConclusionOur findings indicate that specific executive dysfunctions and personality features, particularly those associated with poor emotional control, reduced empathy, and impulsivity are associated with more severe AAS dependence in the SUD population.

Shared polygenic risk for ADHD, executive dysfunction and other psychiatric disorders

Many psychiatric disorders are associated with impaired executive functioning (EF). The associated EF component varies by psychiatric disorders, and this variation might be due to genetic liability. We explored the genetic association between five psychiatric disorders and EF in clinically-recruited attention deficit hyperactivity disorder (ADHD) children using polygenic risk score (PRS) methodology. Genome-wide association study (GWAS) summary data for ADHD, major depressive disorder (MDD), schizophrenia (SZ), bipolar disorder (BIP) and autism were used to calculate the PRSs. EF was evaluated by the Stroop test for inhibitory control, the trail-making test for cognitive flexibility, and the digital span test for working memory in a Chinese ADHD cohort (n = 1147). Exploratory factor analysis of the three measures identified one principal component for EF (EF-PC). Linear regression models were used to analyze the association between each PRS and the EF measures. The role of EF measures in mediating the effects of the PRSs on ADHD symptoms was also analyzed. The result showed the PRSs for MDD, ADHD and BIP were all significantly associated with the EF-PC. For each EF component, the association results were different for the PRSs of the five psychiatric disorders: the PRSs for ADHD and MDD were associated with inhibitory control (adjusted P = 0.0183 and 0.0313, respectively), the PRS for BIP was associated with working memory (adjusted P = 0.0416), and the PRS for SZ was associated with cognitive flexibility (adjusted P = 0.0335). All three EF measures were significantly correlated with ADHD symptoms. In mediation analyses, the ADHD and MDD PRSs, which were associated with inhibitory control, had significant indirect effects on ADHD symptoms through the mediation of inhibitory control. These findings indicate that the polygenic risks for several psychiatric disorders influence specific executive dysfunction in children with ADHD. The results helped to clarify the relationship between risk genes of each mental disorder and the intermediate cognitive domain, which may further help elucidate the risk genes and motivate efforts to develop EF measures as a diagnostic marker and future treatment target.

Executive Function as a Risk Factor for Incisor Trauma.

Executive function is the ability to guide behavior to achieve goals or complete tasks. This study explored the relationship between executive function, as assessed by the Behavior Rating Inventory of Executive Function Parent Form Questionnaire (BRIEF® ) and incisor trauma. This study included children in the mixed dentition with recent incisor trauma (n=28) and a control group (n=30) without recent incisor trauma. Subjects' parents completed the BRIEF® , while a clinical examination assessed subjects' occlusal relationships. Parents also completed a custom questionnaire that investigated their child's medical history and daily activities. Fisher Exact and unpaired t-tests compared BRIEF® scores, occlusal characteristics, medical history, and reported daily activities of the two groups. The trauma group had a greater percentage of participants with a Class II dental relationship (p=0.01). There was no significant difference between groups with respect to mean BRIEF® t-scores within the Global Executive Composite. There was a statistically significant difference between groups with respect to the percentage of subjects with clinically significant (≥65) BRIEF® t-scores within the Inhibit (p=0.05) and Emotional Control (p=0.02) subscales and Behavioral Regulation Index (p=0.02). There were no statistically significant differences between groups with respect to age, gender, overbite, overjet, medical history, body mass index, or daily activities. Children in the mixed dentition with a Class II dental relationship are at greater risk for incisor injury, as well as those involved in outdoor activities. Specific executive dysfunctions such as impulsivity and poor emotional control may increase the risk for incisor trauma. This article is protected by copyright. All rights reserved.

Neuropsychological Profile of Specific Executive Dysfunctions in Patients with Deficit and Non-deficit Schizophrenia.

Objectives: Although it has been shown that there are more profound deficits present in deficit schizophrenia (DS) patients than in non-deficit schizophrenia (NDS) patients, there still remain some matters requiring further investigation. In this context, we formulated three research aims: (1) to compare executive functions between the investigated groups, (2) to determine the relationship between particular aspects of executive functions within the groups, and (3) to draw up a neuropsychological profile for executive functions.Methods: The study involved 148 schizophrenia patients divided into two groups on the basis of the Schedule for the Deficit Syndrome: DS (n = 70) and NDS (n = 78). Patients were matched for sex, age, years of education, and overall cognitive functioning. For assessing executive functions we used the Wisconsin Card Sorting Test (WCST), the Trail Making Test (TMT), the Phonemic Verbal Fluency Test (VFT P), the Stroop Color and Word Test (SCWT), and the Go/No Go task (GNG).Results: Deficit schizophrenia patients scored lower on the WCST and TMT (relative flexibility) than did the NDS patients. There were no inter-group differences in the VFT P, SCWT (relative inhibition), or GNG. There were significant correlations between WCST and TMT scores in both groups. The general neuropsychological profiles were similar in both groups.Conclusion: Deficit schizophrenia patients exhibited slightly greater interference with concept formation and non-verbal cognitive flexibility. Therefore, such problems may be specific to this particular type of schizophrenia. These results may be useful for the development of neuropsychological diagnostic methods for patients with schizophrenia.

Executive dysfunction has common pathways in psychopathology in youth

Many children with psychiatric disorders also have deficits in executive function. However, it's not clear how specific executive dysfunction is to these disorders; there is also extensive comorbidity. So researchers used brain imaging during a task to find out what types of symptoms are associated with executive dysfunction.

The neural correlates of specific executive dysfunctions in Parkinson's disease.

Several functional neuroimaging studies in patients with Parkinson's disease (PD) have suggested that changes in the fronto-parietal-striatal networks are associated with deficits in executive functioning. However, executive functions (EF) are multifaceted and include three dissociable components: working memory, response inhibition, and task-switching. This study investigated which component of executive functioning is most strongly associated with fronto-parietal-striatal efficiency in PD. PD patients (with and without executive dysfunction), and age-matched healthy subjects, completed a battery of cognitive tests previously shown to discriminate among the three EF components. Principal component analysis conducted on the selected cognitive test variables yielded three expected EF components. The component scores were used in regression analysis to assess the relationship between the EF efficiency and blood oxygenation level-dependent (BOLD) signal related to performing the n-back, an experimental task that draws upon multiple components of executive functioning: working memory, response inhibition, and task-switching. We found distinct neural correlates of specific executive dysfunctions in patients with PD. However, all of them seem to be associated with fronto-parietal-striatal efficiency.

The neural correlates of specific executive dysfunctions in Parkinson's disease.

Several functional neuroimaging studies in patients with Parkinson's disease (PD) have suggested that changes in the fronto-parietal-striatal networks are associated with deficits in executive functioning. However, executive functions (EF) are multifaceted and include three dissociable components: working memory, response inhibition, and task-switching. This study investigated which component of executive functioning is most strongly associated with fronto-parietal-striatal efficiency in PD. PD patients (with and without executive dysfunction), and age-matched healthy subjects, completed a battery of cognitive tests previously shown to discriminate among the three EF components. Principal component analysis conducted on the selected cognitive test variables yielded three expected EF components. The component scores were used in regression analysis to assess the relationship between the EF efficiency and blood oxygenation level-dependent (BOLD) signal related to performing the n-back, an experimental task that draws upon multiple components of executive functioning: working memory, response inhibition, and task-switching. We found distinct neural correlates of specific executive dysfunctions in patients with PD. However, all of them seem to be associated with fronto-parietal-striatal efficiency.

Executive Functioning in People With Obsessive-Compulsive Personality Traits: Evidence of Modest Impairment

Investigations of executive dysfunctions among people with obsessive-compulsive personality disorders (OCPD) have yielded inconsistent results. The authors speculate that obsessive-compulsive personality traits (OCPT) from a nonclinical population may be associated with specific executive dysfunctions relative to working memory, attentional set-shifting, and planning. A sample consisting of 79 adults (39 females, 40 males) was divided into high and low scorers on the Personality Diagnostic Questionnaire-4 (PDQ-4; Hyler, 1994). In addition, these participants were interviewed using the SCID-II (First, Spitzer, Gibbon & Williams, 1997) to confirm the presence of symptoms of obsessive-compulsive personality. Participants completed a battery of executive tasks associated with the Cambridge Neuropsychological Test Automated Battery (CANTAB), including Spatial Working Memory, Intradimensional/Extradimensional (ID/ED), Attentional Set-Shifting, and Stockings of Cambridge. Also, self-report measures of executive functions as well as of anxiety and depressive symptoms were administered. The analysis of covariance revealed significant differences between participants with OCPT and controls on the Spatial Working Memory tasks, ID/ED tasks, Stockings of Cambridge, and the Dysexecutive Questionnaire (DEX). Nevertheless, there were no significant differences in the number of problems solved in minimum movements. These results suggest that executive dysfunctions are present in people with prominent OCPT and that there is a high convergence between clinical and ecological measures of executive functions in people with obsessive personality traits.

Evidence for subtle verbal fluency deficits in occasional stimulant users: Quick to play loose with verbal rules

Psychostimulants like cocaine and amphetamine are commonly abused by young adults who often state that they take these drugs to increase social or cognitive performance. The current study tested the hypothesis that individuals at early stages of occasional stimulant use show subtle executive dysfunctions such as verbal fluency deficits. 155 young (age 18–25), non-dependent occasional users of stimulants and 49 stimulant naïve comparison subjects performed the Delis-Kaplan Verbal Fluency test. Correlation and median split analyses were conducted to account for stimulant history and co-drug use. Compared to stimulant naïve subjects, occasional stimulant users generated significantly more responses on an over-learned verbal fluency task (Category Fluency), but at the expense of increased error rates (Set Loss and Repetition Errors). These performance differences were not related to lifetime uses of stimulants or marijuana. Taken together, these results support the hypothesis that individuals who are using stimulants occasionally exhibit subtle executive dysfunctions when required to generate verbal sets under time pressure. In particular, occasional stimulant users apply quickly but inaccurately verbal rules, which may represent a mix of diminished cognitive flexibility along with increased rigidity and impulsivity. This specific executive dysfunction may help to identify individuals at risk for stimulant use or dependence.

Specific executive dysfunction in patients with first-episode medication-naïve schizophrenia

Many studies have shown that schizophrenia is associated with a wide range of cognitive impairments. Empirical findings suggest that patients with schizophrenia suffer from a “dysexecutive syndrome”. However, the extent to which a general decline in neuropsychological function accounts for symptoms of executive dysfunction in schizophrenia is not clear. In this study, we examined further the nature and pattern of executive function in a sample of medication-naïve patients experiencing a first-episode of schizophrenia with a set of tests capturing the specific components of executive function. We also compared the performance of this clinical group with healthy controls. A total of 78 medication-naïve patients with first episode schizophrenia were recruited from the Early Assessment Service for Young People with Psychosis (EASY). Another 60 healthy controls were recruited for comparison. All subjects participated in a comprehensive set of executive function tests assessing initiation, sustained attention, online updating, switching, attention allocation, inhibition, and non-executive function. The executive function of patients with first-episode schizophrenia was found to be compromised relative to healthy controls. However, unlike patients with established schizophrenia, first episode patients exhibited only a limited deficit in sustained attention. Moreover, the majority of executive function deficits did not correlate with intellectual functioning and memory impairment in a sub-group of first episode patients without intellectual impairment. These findings suggest that first-episode patients exhibit a specific pattern of executive dysfunction compared to healthy controls and patients with an established illness. This differential breakdown of executive function components is unlikely to be an artefact of general intellectual decline or memory impairment in schizophrenia.

Maladaptive conflict monitoring as evidence for executive dysfunction in children with chromosome 22q11.2 deletion syndrome

Using an adaptation of the Attentional Networks Test, we investigated aspects of executive control in children with chromosome 22q11.2 deletion syndrome (DS22q11.2), a common but not well understood disorder that produces non-verbal cognitive deficits and a marked incidence of psychopathology. The data revealed that children with DS22q11.2 demonstrated greater difficulty than controls in locating and processing target items in the presence of distracters. Importantly, children with DS22q11.2 showed a deficit in the ability to monitor and adapt to stimulus conflict. These data provide evidence of inadequate conflict adaptation in children with DS22q11.2, a problem that is also present in schizophrenia. The findings of specific executive dysfunction in this group may provide a linkage between particular genetic abnormalities and the development of psychopathology.