Measures Of Executive Function Research Articles

An examination of executive functioning in adolescents with FASD in a self-regulation intervention

Adolescents with Fetal Alcohol Spectrum Disorder (FASD) often have challenges with executive functioning (EF), which impacts their ability to self-regulate. In this study, 23 adolescents with FASD completed a self-regulation intervention. The intervention was a manualized Teen Adaptation of the Alert Program®. A nonrandomized waitlist control design was used, and participants completed pre- and post-testing using performance-based measures of EF, and rating scales of EF were completed by caregivers. Results were analyzed three ways; 1) intervention and waitlist control group comparison, 2) whole sample pre-and post- test comparison, and 3) using Reliable Change Indexes to examine individual-level clinically relevant changes. No significant intervention effects were found when comparing the intervention and waitlist control groups. A significant difference was found on a measure of verbal inhibition when total sample pre-and post-test scores were compared. Using Reliable Change Index analysis, 30% participants showed reliable change in the direction of improvement on direct measures of EF, and 57% demonstrated reliable change in the direction of improvement on rating scales. This research study underscores the importance of investigating both individual and group level changes when analyzing data, as well as using reliable change to understand clinically meaningful effects that may be otherwise masked. These findings highlight the potential of the SR intervention to positively impact EF in adolescents with FASD. This study contributes to the growing literature that demonstrates the potential of individuals with FASD to benefit from direct intervention.

Cognition and Functional Capacity: An Initial Comparison of Veteran and Non-Veteran Older Adults.

The U.S. Military Veterans aged 65 and older comprise an estimated 43% of the 22 million living Veterans in the United States. Veterans have high rates of physical, psychiatric, and social challenges, but it is not known whether Veteran status confers additional risk for cognitive or functional impairments in later life. Thus, this investigation specifically compared older Veterans with their non-Veteran peers in cognitive functioning and performance-based functional capacity. Participants (N = 110; 29 Veterans and 81 non-Veterans) were part of a larger longitudinal study on biopsychosocial functioning in independently living older adult residents of a Continuing Care Senior Housing Community. The University of California San Diego Institutional Review Board approved the study and all participants provided written informed consent. Participants provided demographic and mental health information and were administered a comprehensive neuropsychological battery. Functional capacity was assessed using the UCSD Performance-Based Skills Assessment-Brief (UPSA-B), which uses financial and communication role-plays to assess everyday functioning skills. Neuropsychological scores were appropriately normed prior to analysis. Multivariate Analyses of Variances with post hoc t-tests and an Analysis of Covariance were used to examine neuropsychological and functional capacity differences, respectively, between Veterans and non-Veterans. Veterans did not differ from non-Veterans in educational attainment (16.4 years versus 15.5 years, P = 0.110), but they were significantly older (mean age 86.9 years ± 5.7, versus 81.74 years ± 6.53; P < 0.001) and were more likely to be male (X2 [1, N = 110] = 62.39, P < 0.001). Thus, though neuropsychological norms already accounted for demographic differences in our participants, age and sex were controlled in the Analysis of Covariance predicting UPSA-B score from Veteran status. Results suggested that, compared to non-Veterans, Veterans had significantly worse performance in the list learning portion of a test of verbal memory (Hopkins Verbal Learning Test-Revised, Total Recall; t = 2.56, P = 0.012, d = 0.56). Veterans and non-Veterans did not significantly differ in performance on the delayed recall portion of the verbal learning test and did not differ on a cognitive screening test (Montreal Cognitive Assessment) or on measures of premorbid intellectual functioning (Wide Range Achievement Test-4 Reading), language (Boston Naming Test, Verbal Fluency), visual memory (Brief Visuospatial Memory Test-Revised), attention/working memory (WAIS-IV Digit Span), processing speed (WAIS-IV Digit Symbol Coding), executive function (Delis-Kaplan Executive Function System Trails and Color-Word Test), or functional capacity (UPSA-B). Because our examination of multiple outcomes might have inflated Type I error, we performed a post hoc adjustment of P values using Benjamini-Hochberg procedures and the group difference in verbal learning remained significant. Despite largely similar function in most domains, Veterans performed significantly more poorly in verbal list learning than their non-Veteran peers. Additional attention should be given to the understanding, assessment, and possible treatment of learning and memory differences in older Veterans, as this may be an area in which Veteran status confers additional risk or vulnerability to decline. This is the first study to compare objective neuropsychological and functional performance between older (age 65+) US Veterans and non-Veterans.

Computerized assessment of executive functioning: Validation of the CNS Vital Signs executive functioning scores in a sample of community-dwelling older adults

Objective: Computerized assessment of cognitive functioning has gained significant popularity over recent years, yet options for clinical assessment of executive functioning (EF) are lacking. One computerized testing platform, CNS Vital Signs (CNS-VS), offers tests designed to measure EF but requires further validation. The goal of the present study was to validate CNS-VS executive scores against standard clinical measures of EF. We also sought to determine whether a modified CNS-VS composite score that included variables purported to measure inhibition, switching, and working memory would outperform the currently available CNS-VS Executive Function Index. Method: A sample of 73 cognitively healthy older adults completed four tests from the Delis-Kaplan Executive Function System, the Digit Span subtest from the Wechsler Adult Intelligence Scale-fourth edition, and three CNS-VS tasks purported to measure inhibition, switching, and working memory. Results: Performances on the CNS-VS tests were predicted by performances on standard paper-and-pencil measures. Although the currently available CNS-VS Executive Function Index predicted unique variance in a well-validated paper-and-pencil EF composite score, our Modified CNS-VS EF composite accounted for unique variance above and beyond the original CNS-VS Executive Function Index, while the reverse was not true. Conclusions: The present results support the construct validity of CNS-VS EF tests but also suggest that modifications to their current composite scores would improve the prediction of EF performance.

White Matter Hyperintensities and Microstructural Alterations in Contact Sport Athletes from Adolescence to Early Midlife.

Studies have demonstrated associations between cumulative concussion and repetitive head impact exposure (RHI) via contact sports with white matter (WM) alterations later in life. The course of WM changes associated with exposure earlier in the lifespan are unclear. This study investigated alterations in white matter (WM hyperintensity [WMH] volume and microstructural changes) associated with concussion and RHI exposure from adolescence to early midlife, as well as the interaction between exposure and age-cohort (i.e., adolescent/young adult compared to early midlife athlete cohorts) on WM outcomes. Participating football players included an adolescent/young adulthood cohort (n=82; Mage=18.41.7) and an early midlife cohort (37 former collegiate players approximately 15-years removed from sport; Mage=37.71.4). Years of football participation and number of prior concussions were exposures of interest. White matter outcomes included log-transformed manually segmented total WMH volume and neurite orientation dispersion and density imaging metrics of microstructure/organization (isotropic volume fraction[Viso], intra-cellular volume fraction[Vic], and orientation dispersion[OD]). Regression models were fit to test effects of concussion history, years of football participation, and age-cohort by years of football participation with WM outcomes. Spearman's correlations assessed associations between significant WM metrics and measures of cognitive and psychological function. A significant age-cohort by years of participation effect was observed for whole brain white matter OD, B=-0.002, SE=0.001, p=0.001. The interaction was driven by a negative association between years of participation and OD within the younger cohort, B=-0.001, SE=0.0004, p=0.008, whereas a positive association between participation and OD in the early midlife cohort, B=0.001, SE=0.0003, p=0.039, was observed. Follow-up ROI analyses showed significant interaction effects for OD in the body of the corpus callosum, genu of the corpus callosum, cingulum, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, posterior thalamic radiation (ps<0.05). Greater concussion history was significantly associated with greater Viso in the early midlife cohort, B=0.001, SE= 0.0002, p=0.010. Years of participation and concussion history were not associated with WMH volume, ps>0.05. Performance on a measure of executive function was significantly associated with years of participation, =.34, p=.04, and a trend was observed for OD, =.28, p=.09 in the early midlife cohort only. The global characterization of white matter changes associated with years of football participation were broadly similar and stable from adolescence through early midlife (i.e., microstructural alterations, but not macroscopic lesions). An inverse association between years of participation and orientation dispersion across age-cohorts may represent a process of initial recovery/reorganization proximal to sport, followed by later reduction of white matter coherence.

Validity of the brief executive-function assessment tool in an outpatient substance use disorder setting

The Brief Executive-function Assessment Tool (BEAT) was developed and validated for use in residential substance use disorder treatment settings, where participants are mostly abstinent. It is therefore unclear whether the BEAT is valid for use in outpatient settings, where participants may be actively using substances. The effects of acute intoxication and withdrawal have the potential to alter the results of the BEAT. The current study sought to establish construct and criterion validity of the BEAT in an outpatient substance use disorder sample and to detect its sensitivity to substance use over the previous 24 hours and also over the past month. A total of 74 clients of a New South Wales-based outpatient substance use disorder service participated in the current study. Construct validity was demonstrated by significant correlations between the BEAT and three performance-based tests of executive functioning. Criterion validity was established in that the BEAT discriminated between those deemed impaired or not on a criterion composite measure of executive functioning. Test operating characteristics (88% sensitivity, 69% specificity, 44% PPV, and 95% NPV) were also established relative to this composite measure as a reference standard. The BEAT was insensitive to use/abstinence over the previous 24 hours and the past month.

A brief mindfulness-based intervention for stress, pain, emotion and attention regulation in military service members with mild traumatic brain injury.

The primary aim of this study was to conduct an open pilot clinical trial of a brief mindfulness-based intervention for persistent postconcussion symptoms that occur after mild traumatic brain injury in military service members. For many service members, operational tempo and other time constraints may prevent them from completing a standard mindfulness-based stress reduction course. Thus, this study sought to examine the effectiveness of a five-session intervention called mindfulness-based stress, pain, emotion, and attention regulation (MSPEAR). Participants were active duty service members with a history of mild traumatic brain injury (TBI) and persisting postconcussion symptoms, all of whom were recruited from an outpatient TBI rehabilitation program at a military treatment facility. Of the 38 service members that were initially enrolled, 25 completed the 5-session MSPEAR intervention, and 20 returned for a 5-week follow-up evaluation. Questionnaires assessing perceived stress, positive affect, pain interference and catastrophizing, sleep disturbances, perceived behavioral and attention regulation, self-efficacy and satisfaction with life were administered at preintervention, postintervention, and at 5-week follow-up intervals. Neuropsychological testing at preintervention and 5-week follow-up included performance validity measures, attention, working memory, and executive function measures. T-tests were run to compare for questionnaire measures at preintervention (Time 1) to postintervention (Time 2). Repeated analysis of variances were conducted to compare questionnaire and neuropsychological measures at Time 1, Time 2, and at Time 3 which is the 5-week follow-up. Improvements in perceived stress, positive affect, behavioral regulation, metacognition, sleep disturbance, self-efficacy, and satisfaction with life were found immediately after the MSPEAR intervention and were maintained at the 5-week follow-up. Magnification and helplessness aspects of pain catastrophizing improved when comparing preintervention to the 5-week follow-up. Pain interference was not significantly different across study assessment times. Neuropsychological testing revealed improvements in sustained attention, working memory, cognitive flexibility, and inhibitory control when comparing preintervention to the 5-week follow-up assessment. The MSPEAR intervention appears to show promise as a brief and effective therapy for specific postconcussion symptoms after mild traumatic brain injury in military service members. Each of the components of MSPEAR including stress, pain catastrophizing, emotion and attention regulation showed improvements in this study, and bears further investigation in a larger scale, preferably randomized controlled trial in those active duty military service members who experience persisting symptoms after a mild traumatic brain injury.

Effect of digital natives on executive function: The mediating role of problematic Internet use

The ever-increasing use of digital technology is considered to be related to the individual’s executive function. However, the mechanisms underlying this relationship remain unclear. This questionnaire-based study explored the mediating effect of problematic Internet use (PIU) in the relationship between digital natives and executive function. A total of 572 college students were enrolled to complete the measures of digital natives, PIU, executive function, and demographic variables. Structural equation models were adopted to examine the potential mediating effect of PIU on the relationship between digital natives and executive function. The results revealed that PIU mediates the relationship between global digital natives and global executive function. Moreover, the separate mediation models indicated that PIU mediated the relationship between four dimensions of digital natives and three executive function components. This study advances our knowledge of how digital natives are related to executive function. Education professionals should focus on college students suffering from excessive digital technology, particularly those with PIU.

History of traumatic brain injury is associated with increased grey-matter loss in patients with mild cognitive impairment.

To investigate whether a history of traumatic brain injury (TBI) is associated with greater long-term grey-matter loss in patients with mild cognitive impairment(MCI). 85 patients with MCI were identified, including 26 with a previous history of traumatic brain injury (MCI[TBI-]) and 59 without (MCI[TBI+]). Cortical thickness was evaluated by segmenting T1-weighted MRI scans acquired longitudinally over a 2-year period. Bayesian multilevel modelling was used to evaluate group differences inbaseline cortical thickness and longitudinalchange, as well as group differences in neuropsychological measures of executive function. At baseline, theMCI[TBI+] group had less grey matter within right entorhinal, left medial orbitofrontal and inferior temporal cortexareas bilaterally. Longitudinally, theMCI[TBI+] group also exhibited greater longitudinal declines in left rostral middle frontal, the left caudal middle frontal and left lateral orbitofrontalareas sover the span of 2years (median = 1-2%, 90%HDI [-0.01%: -0.001%], probability of direction(PD) = 90-99%). The MCI[TBI+] group also displayedgreater longitudinal declines in Trail-Making-Test (TMT)-derived ratio (median: 0.737%, 90%HDI: [0.229%: 1.31%], PD = 98.8%) and differences scores (median: 20.6%, 90%HDI: [-5.17%: 43.2%], PD = 91.7%). Our findings support the notion that patients with MCI and a history of TBI are at risk of accelerated neurodegeneration, displayinggreatest evidence for cortical atrophy within the left middle frontal and lateral orbitofrontal frontal cortex. Importantly, these results suggest that long-term TBI-mediated atrophy is more pronounced in areas vulnerable to TBI-related mechanical injury, highlighting their potential relevance for diagnostic forms of intervention in TBI.

Clinical Utility of the Neuropsychological Assessment Battery Judgment Subtest in the Evaluation of Older Adults.

The purpose of this retrospective archival study was to explore the clinical utility of the Judgment subtest of the Neuropsychological Assessment Battery (NAB) in older adults who were referred because of cognitive concerns. Specifically, we were interested in how NAB Judgment covaried with other measures of executive functioning. 226 adults, aged 61-89years (48% dementia, 35% mild cognitive impairment, 18% cognitively intact) completed NAB Judgment. They also completed Trail Making Test (TMT) A and B. In addition, Behavior Rating Inventory of Executive Function (BRIEF-A) informant and self-reports were obtained to measure executive functioning in daily life. Scores on NAB Judgment did not correlate significantly with BRIEF-A informant ratings. However, there was a statistically significant correlation between BRIEF-A informant ratings and TMT B. Better performance on TMT B was associated with fewer informant concerns. Furthermore, subgroups with versus without informant BRIEF-A Metacognition indices in the range of impairment demonstrated a statistically significant difference on TMT B but not on Judgment. Executive functioning in older adults should not be assessed using NAB Judgment alone. Such an evaluation should be supplemented with other in-person tests as well as informant ratings of daily functioning.

Associations of prenatal stress with 5-year-old children's executive function in a low socioeconomic status population.

Prenatal stress has a significant, but small, negative effect on children's executive function (EF) in middle and high socioeconomic status (SES) households. Importantly, rates and severity of prenatal stress are higher and protective factors are reduced in lower SES households, suggesting prenatal stress may be particularly detrimental for children's EF in this population. This study examined whether prenatal stress was linked to 5-year-old's EF in a predominantly low SES sample and child sex moderated this association, as males may be more vulnerable to adverse prenatal experiences. Participants were 132 mother-child dyads drawn from a prospective prenatal cohort. Mothers reported on their depression symptoms, trait anxiety, perceived stress, everyday discrimination, and sleep quality at enrollment and once each trimester, to form a composite prenatal stress measure. Children's EF was assessed at age 5 years using the parent-report Behavior Rating Inventory of Executive Function - Preschool (BRIEF-P) Global Executive Composite subscale and neuropsychological tasks completed by the children. Mixed models revealed higher prenatal stress was associated with lower BRIEF-P scores, indicating better EF, for females only. Higher prenatal stress was associated with lower performance on neuropsychological EF measures for both males and females. Results add to the limited evidence about prenatal stress effects on children's EF in low SES households.

Longitudinal neurocognitive trajectories and risk factors in the first three months following pediatric concussion

ABSTRACT Objective To identify differential trajectories of neurocognitive outcomes following pediatric concussion and investigate predictors associated with patterns of recovery up to 3 months. Methods 74 participants aged 8–17 years completed attention/working memory, processing speed, and executive function measures at 2 weeks, 1 month, and 3 months post-injury. We used principal component analysis to generate a composite of information processing. Group-based trajectory modeling identified latent trajectories. Multinominal logistic regression was used to examine associations between risk factors and trajectory groups. Results We identified three trajectories of neurocognitive outcomes. The medium (54.6%) and high improving groups (35.8%) showed ongoing increase in information processing, while the low persistent group showed limited change 3 months post-injury. This group recorded below average scores on Digit Span Forward and Backward at 3 months. History of pre-injury headache was significantly associated with the persistent low scoring group, relative to the medium improving (p = 0.03) but not the high improving group (p = 0.09). Conclusions This study indicates variability in neurocognitive outcomes according to three differential trajectories, with groups partially distinguished by preexisting child factors (history of frequent headaches). Modelling that accounts for heterogeneity in individual outcomes is essential to identify clinically meaningful indices that are indicative of children requiring intervention.

The Role of Everyday Executive Function in Observed Social Symptoms of Autism Spectrum Disorder.

Recent research suggests there may be differences in the social presentations of autistic males and females. Camouflaging is believed to account for some of these differences and executive function (EF) may support compensatory social behaviors. As few studies have explored the role of sex and everyday EF when evaluating specific social difficulties among autistic youth, the present study seeks to address this. The Social Responsiveness Scale-2 (SRS-2) was used to measure types of social difficulties and the Behavioral Rating Inventory of Executive Function-2 (BRIEF-2) served as a measure of everyday EF. Four three-step hierarchical multiple regressions were conducted with SRS-2 social subscales as dependent variables. Autism symptom severity, BRIEF-2 EF Indices (i.e., behavioral, emotional, and cognitive regulation), and sex served as independent variables. Types of EF impairment significantly predicted social symptoms of autism. Behavioral dysregulation predicted all social symptoms assessed, cognitive dysregulation predicted social awareness and communication challenges, and emotion dysregulation predicted social motivation and communication difficulties. Sex significantly predicted social communication and cognition challenges, beyond the contributions of age, IQ, autism severity, and EF impairment. Findings from this study provide evidence for the contribution of EF to observed social symptoms of autism. Results suggest there may be sex-based differences in the relationship between EF and social problems for autistic youth. Implications and future directions are discussed.

Association between Flavonoid Intake and Cognitive Executive Function among African American and White Adults in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) Study.

Healthy dietary patterns rich in flavonoids may benefit cognitive performance over time. Among socioeconomically disadvantaged groups, the association between flavonoid intake and measures of cognition is unclear. This study sought to identify associations between flavonoid intake and cognitive performance among Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study participants (n = 1947) across three study visits. Flavonoid intakes were assessed via two 24-h dietary recalls. Cognitive performance was assessed via the Trail Making Test (TMT)-A and TMT-B, which provide measures of attention and executive function, respectively. Mixed effects linear regression was used to model TMT scores over three study visits against visit 1 (v1) flavonoid intake, time (years from v1), and the interaction between v1 flavonoid intake and time, capturing both the cross-sectional association between flavonoid intake and time at v1 as well as the longitudinal association between v1 flavonoid intake and the change in TMT scores over time. Prior to adjustment, inverse cross-sectional associations at v1 were observed between (1) anthocyanidin intake and TMT-A scores for the overall sample and (2) total flavonoid, anthocyanidin, flavan-3-ol, flavone, and flavonol intake and TMT-B scores for the overall sample and among White adults. Only the association between anthocyanidin intake and TMT-B at v1 among White adults persisted after adjustment (for demographic characteristics such as age). One possible explanation for the few significant associations is universally low flavonoid intakes resulting from the consumption of an unhealthy dietary pattern.

The relationships between motor skills and executive functions in children with and without autism spectrum disorder.

To date, information on associations between motor skills and executive functions (EF) in autistic children is limited. The purpose of this study was to compare motor skills and EF performance between autistic children and typically developing (TD) children and to examine the relationships between motor skills and EF in these two groups. Forty-eight autistic children and 48 TD children aged 6 to 12 years were recruited for this study. Motor skills were measured with the Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2). EF was assessed with the Stroop Color and Word Test, the Wisconsin Card Sorting Task (WCST), and the Test of Attentional Performance: Go/No-go test. Independent sample t-tests were used to compare the BOT-2 scores and EF measures between autistic children and TD children. Pearson product-moment correlation and regressions were conducted to assess the relationships between the BOT-2 scores and the EF measures for each group. Results showed that autistic children scored significantly lower than TD children on all four BOT-2 composite scores and a total motor composite. Autistic children also demonstrated significantly lower levels of performance on all EF measures than TD children. Further, autistic children showed more significant associations between motor skills and EF than TD children, particularly pronounced in the domains of fine manual control and manual coordination to cognitive flexibility, as well as manual coordination and inhibitory control. Continued development of motor skills and EF in autistic children is important. The relationships between motor skills and EF were significant among autistic children, suggesting future research on promoting EF through motor skill interventions in autistic children is required.

Cognitive Profiles in Preschool Children at Risk for Co-Occurring Dyslexia and ADHD

Developmental dyslexia and attention-deficit/hyperactivity disorder (ADHD) co-occur in 15–40% of individuals diagnosed with one disorder. Despite substantial research on the cognitive profiles of preschoolers at risk for either dyslexia or ADHD, studies have neglected children at risk for co-occurring dyslexia and ADHD. Thus, our study compared the cognitive profile of preschoolers at risk for dyslexia with the profile of children at risk for co-occurring dyslexia and ADHD. We assessed 50 preschoolers at dyslexia risk (DR), 50 at dyslexia + ADHD risk (DAR), and 48 without risk (NR) (Mage = 67 months). Our assessment encompassed phonological processing, executive functioning (EF), receptive vocabulary, and processing speed. Principal component analysis revealed two distinct components within the measures of EF, a verbal short-term memory and an EF component. ANOVA revealed that the NR group outperformed risk groups across measures, except for cognitive flexibility and delay of gratification. Notably, the DR and DAR groups did not differ in most measures but showed near-significant differences on the EF component, with the DR group having higher composite scores than the DAR group. In conclusion, ADHD risk did not impact the cognitive performance of children at risk for dyslexia but might amplify EF problems that at-risk preschoolers encounter.

Comparative efficacy of different interventions on executive function in adolescents with internet use disorder

BackgroundThe formation and relapse of Internet use disorder (IUD) are related to the decline in executive function. Previous studies have indicated that exercise intervention and high-definition transcranial direct current stimulation (HD-tDCS) can improve the cognitive abilities of adolescents with IUD. However, the combined intervention's impact on executive function in these adolescents remains unclear. Therefore, this study aims to explore the effects and differences of multimodal exercise, HD-tDCS intervention, and combined intervention on the executive function of adolescents with IUD. MethodsForty-eight adolescents with IUD were randomly assigned to the multimodal exercise group, HD-tDCS intervention group, combined intervention group, and control group. The intervention groups received 4 weeks of moderate-intensity multimodal exercise, HD-tDCS intervention (2 mA, 20min/session, 3 times/week), or combined multimodal exercise with HD-tDCS intervention. The control group received conventional educational learning. Executive function measurements were taken before intervention, after intervention, and 2 weeks post-intervention. ResultsCompared to pre-intervention, different interventions effectively improved the behavioral performance of adolescents with IUD in executive function tasks. In comparison to single interventions, the combined intervention significantly outperformed multimodal exercise and HD-tDCS intervention in influencing the executive function (especially inhibitory control and working memory) in adolescents with IUD. ConclusionCombined multimodal exercise with HD-tDCS intervention proves to be an effective means of enhancing executive function in adolescents with IUD, particularly contributing to the improvement of explicit behavioral performance related to executive function.

A preliminary study on the neurocognitive deficits associated with loneliness in young adults.

The experience of loneliness is universal and may have an adverse effect on neurocognitive functioning even at a younger age. Using a comprehensive neurocognitive functioning test (NCFT) battery, we examined the possible negative effects of loneliness on neurocognitive functioning in young adults. The high-loneliness and low-loneliness groups were screened using the UCLA Loneliness Scale v. 3, and measures pertaining to the domains of intelligence, attention, memory, executive function, and psychomotor functioning were tested and compared. As depression and anxiety were significantly higher in the high-loneliness group, an analysis of covariance was conducted. As a result, the high-loneliness group showed significantly poor performance on measures of executive function and attention prior to controlling for depression and anxiety, and executive function retained its significance even after controlling for these variables. Additional analysis showed that depression and anxiety did not significantly mediate the relationship between loneliness and neurocognitive functioning. Such results suggest that loneliness is likely to negatively affect executive functioning and attention in early adulthood and then progressively spread to other domains of cognitive functioning, as reported in the older adult population. The limitations and implications of the present study were considered and addressed.

Evidence for a competitive relationship between executive functions and statistical learning

The ability of the brain to extract patterns from the environment and predict future events, known as statistical learning, has been proposed to interact in a competitive manner with prefrontal lobe-related networks and their characteristic cognitive or executive functions. However, it remains unclear whether these cognitive functions also possess a competitive relationship with implicit statistical learning across individuals and at the level of latent executive function components. In order to address this currently unknown aspect, we investigated, in two independent experiments (NStudy1 = 186, NStudy2 = 157), the relationship between implicit statistical learning, measured by the Alternating Serial Reaction Time task, and executive functions, measured by multiple neuropsychological tests. In both studies, a modest, but consistent negative correlation between implicit statistical learning and most executive function measures was observed. Factor analysis further revealed that a factor representing verbal fluency and complex working memory seemed to drive these negative correlations. Thus, the antagonistic relationship between implicit statistical learning and executive functions might specifically be mediated by the updating component of executive functions or/and long-term memory access.

Linking the neural signature of response time variability to Alzheimer’s disease pathology and cognitive functioning

Abstract Promising evidence has suggested potential links between mind-wandering and Alzheimer’s disease (AD). Yet, older adults with diagnosable neurocognitive disorders show reduced meta-awareness, thus questioning the validity of probe-assessed mind-wandering in older adults. In prior work, we employed response time variability as an objective, albeit indirect, marker of mind-wandering to identify patterns of functional connectivity that predicted mind-wandering. In the current study, we evaluated the association of this connectome-based, mind-wandering model with CSF p-tau/Aβ42 ratio in 289 older adults from the Alzheimer’s Disease NeuroImaging Initiative (ADNI). Moreover, we examined if this model was similarly associated with individual differences in composite measures of global cognition, episodic memory, and executive functioning. Edges from the high response time variability model were significantly associated with CSF p-tau/Aβ ratio. Furthermore, connectivity strength within edges associated with high response time variability was negatively associated with global cognition and episodic memory functioning. This study provides the first empirical support for a link between an objective neuromarker of mind-wandering and AD pathophysiology. Given the observed association between mind-wandering and cognitive functioning in older adults, interventions targeted at reducing mind-wandering, particularly before the onset of AD pathogenesis, may make a significant contribution to the prevention of AD-related cognitive decline.

The association of chemotherapy-induced peripheral neuropathy with reduced executive function in chemotherapy-treated cancer survivors: A cross-sectional study

IntroductionChemotherapy-induced peripheral neuropathy (CIPN) is common and disabling among cancer survivors. Little is known about the association of CIPN with other measures of the nervous system's integrity, such as executive dysfunction. We compared measures of executive function in older chemotherapy-treated cancer survivors with and without CIPN. Materials and MethodsThis cross-sectional study enrolled 50 chemotherapy-treated cancer survivors (65.6 ± 11.5 years, 88% female) post-chemotherapy treatment who were previously referred for outpatient rehabilitation at the request of the cancer survivor or a medical provider. Twenty-two participants (44%) had CIPN defined by patient-reported distal paresthesia or numbness, which began with chemotherapy and continued to the time of cognitive testing. Measures of executive function included Trails-B, Stroop, and rapid reaction accuracy (RRA) and were evaluated between cancer survivors with and without CIPN using t-tests. Multivariable models were then used to determine whether CIPN was an independent determinant of the measures of executive function (Trails-B, Stroop Incongruent, and RRA). Models were adjusted for age, sex, history of anxiety, and benzodiazepine use due to their known associations with CIPN and executive function. ResultsCancer survivors with CIPN (CIPN+) had reduced executive function compared to survivors without CIPN (CIPN-) on Trails-B (CIPN+: 84.9 s ± 44.1 s, CIPN-: 59.1 s ± 22.5 s, p = 0.01), Stroop (CIPN+: 100.6 s ± 38.2 s, CIPN-: 82.1 s ± 17.3 s, p = 0.03), and RRA (CIPN+: 60.3% ± 12.9%, CIPN-: 70.6% ± 15.7%, p = 0.01). There were no differences in cancer stage severity or functional status by patient report or sit-to-stand function. The association between CIPN and reduced executive function was found in multivariable models after adjusting for age, sex, anxiety, and benzodiazepine use for Trails-B (ß:17.9, p = 0.046), Stroop (ß:16.9, p = 0.02), and RRA (ß:-0.072, p = 0.03). DiscussionIn this population, CIPN is associated with reduced executive function in older cancer survivors treated with chemotherapy. Future research is required to further understand this preliminary association, the causality, and the potential risk factors.