Executive Function,Intellectual Decline and Daily Living Skills

ABSTRACT

Understanding the cognitive changes associated with compromised daily living skills in elderly individuals is important for making appropriate recommendations about the capacity for independent functioning. To this end, we retrospectively examined data from 92 elderly individuals presenting with cognitive decline who were administered measures of executive functioning, general intelligence, and daily living skills. Multiple regression analyses were used to examine the relationship between executive functioning and daily living skills, while controlling for age, depression, and either IQ decline or current IQ. Executive functioning accounted for additional variance in a broad range of daily living skills after controlling for IQ decline. When FSIQ was used in the regression model rather than IQ decline, executive functioning was no longer uniquely associated with daily living skills. Executive functions appear to be important for daily living skills until a critical threshold of low intellectual functioning is reached, reflecting the combined influence of premorbid ability and the extent of intellectual decline. Our results suggest that understanding the relative contribution of different cognitive domains to functional decline in elderly individuals should take into account general intellectual functioning and estimated decline, and that the initiation and/or persistence of self-directed cognitive processes may be important for adaptive daily functioning. These findings have implications for making more evidence-based recommendations about the capacity for independent living.     

Processing speed in normal aging: Effects of white matter hyperintensities and hippocampal volume loss

Changes in cognitive functioning are said to be part of normal aging. Quantitative MRI has made it possible to measure structural brain changes during aging which may underlie these decrements which include slowed information processing and memory loss. Much has been written on white matter hyperintensities (WMH), which are associated with cognitive deficits on tasks requiring processing speed and executive functioning, and hippocampal volume loss, which is associated with memory decline. Here we examine volumetric MRI measures of WMH and hippocampal volume loss together in relation to neuropsychological tests considered to be measures of executive functioning and processing speed in 81 non-demented elderly individuals, aged 75–90. Correlational analysis showed that when controlling for age, both greater WMH volume and smaller hippocampal volume were correlated with slower performances on most tests with the exception of a battery of continuous performance tests in which only WMH was correlated with slower reaction time (RT). We then performed a series of hierarchical multiple regression analyses to examine the independent contributions of greater WMH volume and reduced hippocampal volume to executive functioning and processing speed. The results showed that for the four measures requiring executive functioning and speed of processing, WMH volume and hippocampal volume combined predicted between 21.4% and 37% of the explained variance. These results suggest that WM integrity and hippocampal volume influence cognitive decline independently on tasks involving processing speed and executive function independent of age.     

Behavioral dysexecutive symptoms in normal aging

Executive deficits of normal aging such as deficits in planning, organization or decision making are likely to affect elderly individuals in their daily life functioning. Therefore, executive functioning in aging seems to be interesting to study not only in cognitive terms but also in relation to the behavioral area. This pilot study aimed to investigate the nature of behavioral dysexecutive problems in a sample of normal elderly adults as measured by the Dysexecutive Questionnaire. Factor analysis showed that five interpretable factors could be derived from the DEX: intentionality (factor 1), interference management (factor 2), inhibition (factor 3), planning (factor 4), and social regulation (factor 5), suggesting that different components may underlie the behavioral dysexecutive symptoms of normal aging. The relationship between these factors and neuropsychological measures of Executive Functions were also briefly explored.     

Neuropsychological executive functioning in children at elevated risk for alcoholism: findings in early adolescence

One component of individual risk for alcoholism may involve cognitive vulnerabilities prodromal to alcoholism onset. This prospective study of 198 boys followed between 3 and 14 years of age evaluated neurocognitive functioning across three groups who varied in familial risk for future alcoholism. Measures of intelligence, reward-response, and a battery of neuropsychological executive and cognitive inhibitory measures were used. Executive functioning weaknesses were greater in families with alcoholism but no antisocial comorbidity. IQ and reward-response weaknesses were associated with familial antisocial alcoholism. Executive function effects were clearest for response inhibition, response speed, and symbol-digit modalities. Results suggest that executive deficits are not part of the highest risk, antisocial pathway to alcoholism but that some executive function weaknesses may contribute to a secondary risk pathway.     

Performance on the dimensional change card sort and backward digit span by young children with autism without intellectual disability

The early development of executive function (EF) and its relation to autism symptom expression is of considerable theoretical interest, particularly in children without general cognitive delay. Executive function was tested in 23 children with autism spectrum disorders (ASD) without intellectual disability and 20 age- and IQ-matched typically developing children. Even though performance was equivalent between the two groups on tests of general intelligence, flexibility in card sorting was lower for children with ASD. Verbal working memory during the backward digit span did not differ between groups. Among children with ASD, poorer performance on card sorting distinguished a subgroup with worse social-communication functioning above and beyond IQ. Controlling for IQ social and repetitive symptoms of ASD did not differ based on card sorting ability.     

Higher functioning children with prenatal alcohol exposure: Is there a specific neurocognitive profile?

Recent attempts to identify a neurocognitive profile of children with prenatal alcohol exposure (PAE) have led to an emerging “generalized deficit” conceptualization marked by diffuse information processing and integration difficulties as opposed to a specific profile. This study examines whether this conceptualization can be extended to higher functioning children with PAE who are without intellectual disability and addresses several limitations of previous research. One hundred twenty-five children aged 6–12 years with social skills deficits, 97 of whom met diagnostic criteria for a Fetal Alcohol Spectrum Disorder (FASD), underwent a comprehensive, multi-informant assessment of neurocognitive, emotional, social, behavioral, and adaptive functioning. Multivariate analyses of variance examined differences in functioning between the PAE group and a nonexposed comparison group with and without controlling for child IQ. Results indicated that the PAE group returned significantly poorer scores than the nonexposed group on every construct assessed, including executive functioning, attention, working/visuospatial memory, linguistic abstraction, adaptive behavior, emotional/behavioral functioning, and social cognition. These differences largely maintained after controlling for IQ and were similar regardless of informant, although teachers reported somewhat fewer group differences. Within the PAE group, no differences were found across FASD subtypes. These results provide evidence extending the emerging generalized deficit conceptualization of children with PAE to those higher functioning individuals without global intellectual disability.     

Theory of mind in spina bifida: Relationship with intellectual and executive functioning

This article investigates emotion recognition ability, a central aspect of Theory of Mind (ToM), in a group of individuals with spina bifida myelomeningocele (SBM) experiencing executive function deficits, and examine associations between emotion recognition, and intellectual and executive functioning. A total of 38 adult subjects with SBM were included in this study, participating in a randomized controlled trial evaluating the effects of a cognitive rehabilitation intervention for executive dysfunction. Reading the Mind in the Eyes Test (RMET) was used as a measure of emotion recognition, and neuropsychological tests and questionnaires were utilized as executive function measures. One third of the participants performed poorer on the emotion recognition task compared to normative data. Emotion recognition may represent an area being affected in adults with SBM, and it is related to verbal IQ. Findings also suggest that executive functions and emotion recognition ability in adults with SBM are independent.     

Executive functions and social skills in survivors of pediatric brain tumor

Medical advances have resulted in increased survival rates for children with brain tumors. Consequently, issues related to survivorship have become more critical. The use of multimodal treatment, in particular cranial radiation therapy, has been associated with subsequent cognitive decline. Specifically, deficits in executive functions have been reported in survivors of various types of pediatric brain tumor. Survivors are left with difficulties, particularly in self-monitoring, initiation, inhibition, and planning, to name a few. Another domain in which survivors of pediatric brain tumor have been reported to show difficulty is that of social skills. Parents, teachers, and survivors themselves have reported decreased social functioning following treatment. Deficits in executive functions and social skills are likely interrelated in this population, as executive skills are needed to navigate various aspects of social interaction; however, this has yet to be studied empirically. Twenty-four survivors of pediatric brain tumor were assessed using a computerized task of executive functions, as well as paper-and-pencil measures of social skills and real-world executive skills. Social functioning was related to a specific aspect of executive functions, that is, the survivors' variability in response time, such that inconsistent responding was associated with better parent-reported and survivor-reported social skills, independent of intellectual abilities. Additionally, parent-reported real-world global executive abilities predicted parent-reported social skills. The implications of these findings for social skills interventions and future research are discussed.     

Episodic feeling-of-knowing accuracy and cued recall in the elderly: evidence for double dissociation involving executive functioning and processing speed

This research investigated adult age differences in a metamemory monitoring task-episodic feeling-of-knowing (FOK) and in an episodic memory task-cued recall. Executive functioning and processing speed were examined as mediators of these age differences. Young and elderly adults were administered an episodic FOK task, a cued recall task, executive tests and speed tests. Age-related decline was observed on all the measures. Correlation analyses revealed a pattern of double dissociation which indicates a specific relationship between executive score and FOK accuracy, and between speed score and cued recall. When executive functioning and processing speed were evaluated concurrently on FOK and cued recall variables, hierarchical regression analyses showed that executive score was a better mediator of age-related variance in FOK, and that speed score was the better mediator of age-related variance in cued recall.     

Exploitation in Older Adults: Personal Competence Correlates of Social Vulnerability

ABSTRACT

Clinical assessment of older people at heightened risk of financial exploitation (also termed social vulnerability) is a difficult task. There are a number of previously untested domains of personal competence which could influence social vulnerability in later life. In this study, intellectual, cognitive, and social-cognitive functioning was assessed in a combined sample of dementia patients (n = 31) and neurologically healthy individuals (n = 68) aged 50 years or over. Informants provided assessments of participants' social functioning, personality, and social vulnerability. In the combined sample, multiple regression analyses revealed significant relationships between each personal competence domain and (lower) social vulnerability, apart from personality which was non-significant. General cognitive functioning and, in particular, executive functioning showed significant overlap with social vulnerability after controlling for memory and age. Social measures were also important correlates of vulnerability, indicating that both neurocognitive and social cognitive deficits may contribute to financial exploitation in later life.     

Inferior Parietal Perfusion, Lateralization, and Neuropsychological Dysfunction in Alzheimer's Disease

The severity of inferior parietal perfusion deficits in Alzheimer's disease (AD) is strongly associated with global intellectual decline. The relationship to specific losses of neuropsychological functioning, however, is less clear, as is the relative importance of the side (left vs. right) of hemispheric deficit. In this study, 53 patients with probable AD and 35 elderly controls received both a resting¹³³Xe rCBF measurement and neuropsychological examination. AD patients demonstrated the expected bilateral deficits in inferior parietal perfusion, as well as impairment on measures of mental status, intelligence, verbal and visual memory, attention, language, and construction abilities. The severity of this bilateral parietal deficit, in turn, was associated with virtually all of these AD-related neuropsychological impairments, most strongly with declining Performance IQ. Left-sided deficits correlated better with overall declines in IQ, as well as with declining attention and language fluency. Right-sided deficits, on the other hand, correlated best with declines in mental status and—paradoxically—verbal memory and contributed independently to declines in Full Scale and Performance IQ. In terms of the number and strength of their association to neuropsychological measures, left-sided deficits appear much more predictive of cognitive decline in AD. Right-sided deficits, however, may be most important for predicting aspects of performance skill that are only indirectly assessed in standard paper-and-pencil format. Overall, it appears that both sides make significant, but independent contributions to general functional decline in AD, but that left-sided deficits are more closely associated with cognitive decline as measured by most standard neuropsychological measures.     

Impact of cognitive profile on social functioning in prepubescent females with Turner syndrome

Social deficits are prevalent in Turner syndrome (TS); however, the extent to which these difficulties are secondary to characteristic cognitive impairments is not well known. Here, we sought to establish the relative contribution of executive functions, visuospatial abilities, and IQ to social difficulties in young girls with TS. Forty TS girls and 19 typically developing (TD) children were assessed with the Social Responsiveness Scale (SRS), the Motor-Free Visual Spatial Test (MVPT-3), the Behavior Rating Inventory of Executive Function (BRIEF), and an IQ test. Hierarchical multiple regression analyses were conducted with the SRS subscales as outcome variables. In a first step, the cognitive factors were entered (verbal IQ, BRIEF global score, MVPT-3, and age), followed by the group variable in a second step. In comparison to TD, TS participants were significantly impaired on all main measures. All six regression models with the SRS subscales were significant and revealed that global executive functions explained the largest portion of the variance on all subscales and the total score. Even after controlling for cognitive elements, the group factor still explained a significant portion of the variance of the Social Cognition, Social Awareness, and Autistic Mannerisms subscales. In contrast, the group factor was not a significant predictor of Social Motivation and Social Communication scores. These results suggest that executive dysfunctions play a role in social impairments encountered in TS, but also that some specific aspects of social behavior are altered beyond what can be attributed to cognitive difficulties in this population.     

Unraveling the Aging Skein: Disentangling Sensory and Cognitive Predictors of Age‐related Differences in Decision Making

Age‐related differences in sensory functioning, processing speed, and working memory have been identified as three significant predictors of the age‐related performance decline observed in complex cognitive tasks. Yet, the assessment of their relative predictive capacity and interrelations is still an open issue in decision making and cognitive aging research. Indeed, no previous investigation has examined the relationships of all these three predictors with decision making. In an individual‐differences study, we therefore disentangled the relative contribution of sensory functioning, processing speed, and working memory to the prediction of the age‐related decline in cognitively demanding judgment and decision‐making tasks. Structural equation modeling showed that the age‐related decline in working memory plays an important predictive role, even when controlling for sensory functioning, processing speed, and education. Implications for research on decision making and cognitive aging are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Exploring Predictors of Outcome in the Psychosis Prodrome: Implications for Early Identification and Intervention

Functional disability is a key component of many psychiatric illnesses, particularly schizophrenia. Impairments in social and role functioning are linked to cognitive deficits, a core feature of psychosis. Retrospective analyses demonstrate that substantial functional decline precedes the onset of psychosis. Recent investigations reveal that individuals at clinical-high-risk (CHR) for psychosis show impairments in social relationships, work/school functioning and daily living skills. CHR youth also demonstrate a pattern of impairment across a range of cognitive domains, including social cognition, which is qualitatively similar to that of individuals with schizophrenia. While many studies have sought to elucidate predictors of clinical deterioration, specifically the development of schizophrenia, in such CHR samples, few have investigated factors relevant to psychosocial outcome. This review integrates recent findings regarding cognitive and social-cognitive predictors of outcome in CHR individuals, and proposes potential directions for future research that will contribute to targeted interventions and improved outcome for at-risk youth.     

Executive functions in children with Autism Spectrum Disorders

Executive dysfunction is a characteristic impairment of individuals with Autism Spectrum Disorders (ASD). However whether such deficits are related to autism per se, or to associated intellectual disability is unclear. This paper examines executive functions in a group of children with ASD (N = 54, all IQ⩾70) in relation to a typically developing control group individually matched on the basis of age, gender, IQ and vocabulary. Significant impairments in the inhibition of prepotent responses (Stroop, Junior Hayling Test) and planning (Tower of London) were reported for children with ASD, with preserved performance for mental flexibility (Wisconsin Card Sorting Task) and generativity (Verbal Fluency). Atypical age-related patterns of performance were reported on tasks tapping response inhibition and self-monitoring for children with ASD compared to controls. The disparity between these and previous research findings are discussed. A multidimensional notion of executive functions is proposed, with difficulties in planning, the inhibition of prepotent responses and self-monitoring reflecting characteristic features of ASD that are independent of IQ and verbal ability, and relatively stable across the childhood years.     

Executive functions in children with Autism Spectrum Disorders

Executive dysfunction is a characteristic impairment of individuals with Autism Spectrum Disorders (ASD). However whether such deficits are related to autism per se, or to associated intellectual disability is unclear. This paper examines executive functions in a group of children with ASD (N = 54, all IQ?70) in relation to a typically developing control group individually matched on the basis of age, gender, IQ and vocabulary. Significant impairments in the inhibition of prepotent responses (Stroop, Junior Hayling Test) and planning (Tower of London) were reported for children with ASD, with preserved performance for mental flexibility (Wisconsin Card Sorting Task) and generativity (Verbal Fluency). Atypical age-related patterns of performance were reported on tasks tapping response inhibition and self-monitoring for children with ASD compared to controls. The disparity between these and previous research findings are discussed. A multidimensional notion of executive functions is proposed, with difficulties in planning, the inhibition of prepotent responses and self-monitoring reflecting characteristic features of ASD that are independent of IQ and verbal ability, and relatively stable across the childhood years.     

Executive Functioning Predicts Social Skills Following Prenatal Alcohol Exposure

Adverse sequelae of prenatal alcohol exposure include executive function and social skills impairments, although these two domains have not been empirically linked in alcohol-exposed individuals. This study investigated this relationship using the BRIEF and the SSRS in 98 children aged 6 to 11 years. Executive functions explained a significant percentage of variance in parent and teacher rated social skills. No differences were found among children with diagnoses of FAS, partial FAS, or alcohol-related neurodevelopmental disorder. It may be helpful to consider executive functioning in designing social skills interventions for alcohol-exposed children whether or not they have full FAS.     

Executive functioning predicts social skills following prenatal alcohol exposure.

Adverse sequelae of prenatal alcohol exposure include executive function and social skills impairments, although these two domains have not been empirically linked in alcohol-exposed individuals. This study investigated this relationship using the BRIEF and the SSRS in 98 children aged 6 to 11 years. Executive functions explained a significant percentage of variance in parent and teacher rated social skills. No differences were found among children with diagnoses of FAS, partial FAS, or alcohol-related neurodevelopmental disorder. It may be helpful to consider executive functioning in designing social skills interventions for alcohol-exposed children whether or not they have full FAS.     

The influence of functional social support on executive functioning in middle-aged African Americans

Social support has a positive influence on cognitive functioning and buffers cognitive decline in older adults. This study examined the relations between social support and executive functioning in middle-aged adults. A community-based sample of African Americans completed the Interpersonal Support Evaluation List, a measure of functions of social support, and two measures of executive functioning, the Stroop Color and Word Test and the Wisconsin Card Sorting Test (WCST). Hierarchical regression analyses were used to explore the hypothesis that different facets of perceived social support influence performance on measures of executive functioning. After controlling for age, gender, and education, social support facets including belonging support, self-esteem support, appraisal support, and tangible support were significant predictors of Stroop performance. In addition, tangible support significantly predicted WCST performance. These findings add to previous literature on social support and cognition; however, findings for middle-aged adults are unique and suggest that social support has a positive influence on some executive functions in African Americans prior to old age.     

Auditory sensory gating and performance on the Delis–Kaplan Executive Function System

Sensory gating is a neurological mechanism that inhibits redundant sensory information. Impaired sensory gating is not uncommon in otherwise healthy individuals, but its relationship with higher level cognitive function is poorly understood. It is plausible that cognitive fragmentation associated with poor sensory gating may affect an individual's higher level executive functioning. Fifty-one participants (Mean age?=?22.02; 24 males) were administered an electroencephalogram with a paired-tone paradigm to measure sensory gating as well as a comprehensive executive functioning battery—the Delis–Kaplan Executive Function System. Overall, better performance on the D-KEFS was related to more effective sensory gating. Also, tasks that measured cognitive flexibility predicted P50 latency as well as P200 amplitude and sensory gating. Understanding the relationship between sensory gating and cognitive processing has implications for healthy individuals and clinical groups alike.