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.     

Walking Speed and Global Cognition: Results from the OKLAHOMA Study

ABSTRACT

Executive functioning and processing speed have been related to physical functioning in non-demented, elderly samples; however, the relationship between walking speed and global cognition has not been examined. Six hundred and seventy-five community dwelling older adults were enrolled through their primary care physicians. Walking speed was assessed on a 50-foot course at usual pace. Global cognition was assessed with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Total Scale score. After adjusting for age, gender, and education, there was a strong inverse relationship between walking speed and global cognition, with slower walkers performing worse on the cognitive measures, faster walkers performing better on the cognitive measures, and the intermediate walkers performing in the middle. In these older adults, global cognition was related to walking speed.     

Executive function, intellectual decline and daily living skills

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.     

Neurobehavioural profile following cumulative mild traumatic brain injury in adolescent rugby players in South Africa

The study investigated the neurobehavioural components of executive dysfunction following sport-related Mild Traumatic Brain Injury (MTBI) in Grade 12 adolescent rugby players over a rugby season. In a non-equivalent quasi-experimental design, a rugby group (n?=?90) were compared with demographically equivalent noncontact sport controls (n?=?59). The Behaviour Rating Inventory of Executive Functions – Self Report (BRIEF-SR) was employed to assess the neurobehavioural component of executive functions. Independent and dependent t-test analyses were conducted to compare the groups at baseline and end-of-season intervals. The overall findings suggest more pronounced deleterious effects on executive functioning from exposure to the concussive and sub-concussive events among the rugby group. High school rugby players experience adverse neurobehavioural effects in executive dysfunction from contact rugby sport injuries.     

A developmental perspective on decision making in young soccer players: The role of executive functions

Lately, interest in both domain-specific and domain-general cognitive processes has increased as a means to explain soccer player expertise. While the two types of processes have mostly been studied separately, we sought to connect these lines of research by investigating the role of executive functions in soccer players’ decision making from a developmental perspective. As these cognitive processes as well as their relation might differ between age groups, we took a developmental perspective to better understand this link in a sample of N = 128 soccer players (M_age = 10.69 years, SD = 1.44). Two age groups (younger vs. older players) performed a video-based option-generation and decision-making task that used temporal occlusion. Additionally, executive functions were assessed with standardized computer-based tests. Results show a link between executive functions and sport-specific decision making, most prominent for working memory. Further, older players generated better options and showed better inhibition and cognitive flexibility than younger players. We suggest there is a crucial turning point in cognitive development around the age of 11 years.     

Parental educational level influence on memory and executive performance in children

IntroductionThe influence of Parental Educational Status (PES) on cognitive performance has been confirmed in several studies.ObjectiveThe aim of this study was to explore the relationship between PES and several domains of cognitive functioning and examine, through mediation analyses, the relationship between PES, language, and cognitive tasks.MethodWe first administered tasks measuring memory, executive and attentional abilities to 64 European native French speakers, divided into two groups of children according to parents’ educational status.ResultsThe results suggest that, on most tasks, the effect of socio-educational status is mediated by language abilities. However, because the results were less clear for executive functions, we carried out a second experiment in which we administered more specific executive measures (i.e. inhibition, cognitive flexibility, updating and reasoning) to 80 children.ConclusionThe results confirmed the influence of the parents’ educational status on the executive functioning and also that, contrary to other cognitive functions, this influence on executive tasks is not completely explained by language differences.     

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.     

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.     

Age differences in executive functioning across the lifespan: the role of verbalization in task preparation

Age-related changes in executive functioning across the lifespan were assessed in children (mean age=9.4 years), younger adults (mean age=21.5 years), and older adults (mean age=65.3 years). Executive functioning was investigated with a task-switching paradigm that permits the separation of two control components: to select and to switch between task sets. The specific aims of this study were (a) to determine developmental functions in both control components across the lifespan; and (b) to examine whether age-related changes in these components are influenced by verbal prompts during task preparation. The results revealed an inverted u-shaped developmental function for the ability to select between task sets but not for the ability to switch between task sets. In contrast to younger adults and children, older adults generally benefited from verbalizations during task preparation. Children, but not older adults, showed a facilitation of task execution when verbal prompts were task-compatible. Conversely, older adults, but not children, showed stronger interference when verbal prompts are task-incompatible. Our findings suggest that inner speech in an important modulator of developmental changes in executive functioning across the lifespan.     

Aging and time-sharing aspects of executive control

A particularly important aspect of executive functioning involves the ability to coordinate two simultaneous activities. The role of this aspect of executive functioning in adult-age differences in cognitive performance was examined in a study involving 150 adults between 20 and 91 years of age who performed the same visual-motor tracking task with three different primary tasks. The participants also performed several additional cognitive tasks that allowed examination of the relation of time-sharing efficiency to other types of cognitive functioning The results were consistent with the existence of a distinct time-sharing ability because the time-sharing costs in the three dual-task combinations were significantly correlated with one another but only weakly correlated with other cognitive variables. Increased age was associated with reductions in time-sharing ability, and greater efficiency in performing two tasks at once was associated with better performance on tasks assessing spatial, reasoning, and memory abilities. Although this pattern is what one would expect if executive processes contribute to age differences in cognitive functioning, the effects were smaller than those associated with a perceptual speed construct.     

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

ABSTRACT

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, selfesteem 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.     

Association between biological markers of sickle cell disease and cognitive functioning amongst Cameroonian children

Background: Some of the major complications of sickle cell disease (SCD) occur in the brain and apart from overt stroke, patients also present with cognitive impairments. We sought to evaluate the prevalence of cognitive deficits as well as their biological predicting factors in young SCD patients in Cameroon.

Methods: The cognitive performances of Cameroonian SCD young patients were evaluated using a neuropsychological test battery assessing four domains of cognitive functioning (executive functions, attention, memory, and sensory-motor skills) previously adapted and normalized on healthy subjects in Yaoundé.

Findings: Up to 37.5% of the 96 SCD patients aged 6 to 24 years (M?=?13.5, SD?=?4.9) had mild-to-severe cognitive deficits. The cognitive deficits tend to increase with age. There was a significant effect of SCD on executive functions and attention, whereas SCD patients performed as well as controls on memory and sensory-motor skills tests. Structural equation models showed a significant association between (a) severe anemia and lower executive functioning, (b) low fetal hemoglobin levels and lower executive functioning and attention, (c) history of cerebrovascular accidents and lower performances in executive functioning, sensory-motor skills, and memory, (d) pathological electroencephalogram and lower attention, and (e) abnormal Transcranial Doppler and lower memory.

Conclusion: SCD patients in Cameroon presented a very high prevalence of cognitive deficits, with a specific impairment of executive functions and attention. Routine neuropsychological evaluation for early detection of cognitive deficits in SCD patients could represent a cost-effective tool to implement in resource-limited contexts such as in sub-Saharan Africa.     

Walking speed and global cognition: results from the OKLAHOMA Study

Executive functioning and processing speed have been related to physical functioning in non-demented, elderly samples; however, the relationship between walking speed and global cognition has not been examined. Six hundred and seventy-five community dwelling older adults were enrolled through their primary care physicians. Walking speed was assessed on a 50-foot course at usual pace. Global cognition was assessed with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Total Scale score. After adjusting for age, gender, and education, there was a strong inverse relationship between walking speed and global cognition, with slower walkers performing worse on the cognitive measures, faster walkers performing better on the cognitive measures, and the intermediate walkers performing in the middle. In these older adults, global cognition was related to walking speed.     

Differences in the neurocognitive profiles of professional and semi-professional male South African rugby union players

This study investigated possible cognitive functioning profile differences between professional and semi-professional rugby players. Seventy-nine male rugby union players (professional = 55, semi-professional = 24; age range = 19–37 years) participated in the study. The players completed a battery of neuropsychological functioning tests covering the following domains: memory tasks, attention and behavioural tasks, sensory-motor tasks, executive functioning tasks, verbal tasks, and emotion identification tasks. Results following Fisher’s exact test comparisons revealed no significant group differences in the cognitive functioning profiles.     

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.     

Executive performance on the preschool executive task assessment in children with sickle cell anemia and matched controls

Executive deficits are commonly reported in children with sickle cell anemia. Earlier identification of executive deficits would give more scope for intervention, but this cognitive domain has not been routinely investigated due to a lack of age-appropriate tasks normed for preschool children. In particular, information relating to patient performance on an executive task that reflects an everyday activity in the classroom could provide important insight and practical recommendations for the classroom teacher at this key developmental juncture as they enter the academic domain. The performance of 22 children with sickle cell anemia was compared to 24 matched control children on the Preschool Executive Task Assessment. Findings reveal that children with sickle cell anemia are performing poorer than their matched peers on this multi-step assessment. In particular, children with sickle cell anemia required more structured support to shift focus after a completed step, as reflected by poorer scores in the quantitative Sequencing and Completion domains. They also required more support to stay on task, as seen by poorer ratings in the qualitative Distractibility domain.

Abbreviations:PETA: Preschool Executive Task Assessment; SCA: Sickle Cell Anemia; EF: Executive Functioning.     

Correlations among measures of executive function and positive psychological attributes in college students

Executive functions are cognitive abilities that allow for more goal-oriented and autonomous behavior. The authors examined the relationship between self-rated executive functions and 3 positive personality attributes (satisfaction with life, gratitude, and forgiveness) in a nonclinical community sample. The authors used self-report scales (Executive Function Index, Heartland Forgiveness Scale "other" subscale, Satisfaction With Life Scale, and the Gratitude Questionnaire) to examine how executive functions related to the positive psychology attributes. After controlling for age, sex, and formal education, positive relationships emerged among gratitude, satisfaction, and executive function scales of motivational drive, empathy, and strategic planning. However, an inverse relationship emerged between impulse control and forgiveness, perhaps relating to cautiousness and suggesting finer distinctions between adaptive and maladaptive forms of forgiveness. These findings suggest common psychological and neurobiological substrates for executive functions and positive psychology attributes, warranting further, more direct biobehavioral research.     

认知年老化与执行衰退假说

在认知年老化领域,执行衰退假说是近年来新兴的一种理论。执行衰退假说在理论上具有很强的吸引力,但在实证研究中却存在很多困难,如执行功能的可分离性问题,执行功能测量的信度和效度问题,以及执行功能与加工速度的关系问题。目前,该领域研究的焦点是：在行为学水平上,控制一般性因素（加工速度）后,执行功能是否仍对认知年老化起重要的中介作用;在神经水平上,执行（额叶）功能随龄的变化情况,以及在认知年老化过程中,额叶在大脑功能重组中扮演的角色。最终实现对认知年老化的理解,需要将认知功能与大脑结构联系起来;既看到广泛存在的共同的基本机制,又不能忽略不同认知结构的选择性变化。     

Sense of Time and Executive Functioning in Children and Adults

A number of patient studies suggest that impairments in frontal lobe functions are associated with disorders in temporal information processing. One implication of these findings is that subjective experience of time should be related to executive functions regardless of etiology. In two experiments, we examined sense of time in relation to components of executive functioning in healthy children and adults. In Experiment 1, children between 8 to 12 years completed six experimental tasks that tapped three components of executive functioning: inhibition, updating, and mental shifting. Sense of time was examined in a duration judgment task in which participants reproduced stimulus durations between 4 to 32 s. In Experiment 2, adult participants completed the time reproduction task under varying concurrent task demands. Both experiments showed selective effects in that time reproduction errors were related to the inhibition and updating, but not to the shifting, components of executive functioning. However, the observed effects were modulated by task demands and age-related differences in cognitive competence. We conclude that individual differences in executive functioning are only weakly related to time reproduction performance in healthy children and adults.