Prediction of functional status in older adults: The ecological validity of four Delis–Kaplan Executive Function System tests

Conceptualization of the term "ecological validity" in neuropsychological research on executive function assessment: a systematic review and call to action

OBJECTIVE

"Ecological validity" (EV) is classically defined as test's ability to predict real-world functioning, either alone or together with test's similarity to real-world tasks. In neuropsychological literature on assessment of executive functions (EF), EV is conceptualized inconsistently, leading to misconceptions about the utility of tests. The goal of this systematic review was to examine how EV is conceptualized in studies of EF tests described as ecologically valid.

METHOD

MEDLINE and PsychINFO Databases were searched. PRISMA guidelines were observed. After applying inclusion and exclusion criteria, this search yielded 90 articles. Deductive content analysis was employed to determine how the term EV was used.

RESULTS

About 1/3 of the studies conceptualized EV as the test's ability to predict functional outcomes, 1/3 as both the ability to predict functional outcome and similarity to real-world tasks, and 1/3 were either unclear about the meaning of the term or relied on notions unrelated to classical definitions (e.g., similarity to real-world tasks alone, association with other tests, or the ability to discriminate between populations).

CONCLUSIONS

Conceptualizations of the term EV in literature on EF assessment vary grossly, subsuming the notions of criterion, construct, and face validity, as well as sensitivity/specificity. Such inconsistency makes it difficult to interpret clinical utility of tests that are described as ecologically valid. We call on the field to require that, at minimum, the term EV be clearly defined in all publications, or replaced with more concrete terminology (e.g., criterion validity).

Semantic fluency in 3-6 years old preschoolers: which executive functions?

Semantic Fluency (SF) increases with age, along with the lexicon and the strategies to access it. Among the cognitive processes involved in controlling lexical access, Executive Functions (EF) play an essential role. Nevertheless, which EF, namely inhibition, working memory, and cognitive flexibility, are specifically tapped by SF during preschool years, when these basic EF components are developing and differentiating, is still unknown. The study had a two-fold aim: 1. to analyze in preschoolers the role of EF basic components on SF; 2. to investigate if EF mediated the effect of age on SF. A total of 296 typically developing preschoolers (M age = 57.86; SD = 9.91; month range = 33-74) were assessed with an SF task and EF tasks measuring the main EF basic components. Results showed that during preschool, response inhibition, working memory, and cognitive flexibility were significant predictors of SF, explaining 27% of its variance. Moreover, the effect of age on the SF task performance correlated with the improvement of these EF components. This study supports the importance of considering cognitive control processes in 3-6 year-old preschoolers as they underline important competencies for the child's development, such as the ability to quickly access vocabulary.

Amplitude-determined seizure-threshold, electric field modeling, and electroconvulsive therapy antidepressant and cognitive outcomes

Electroconvulsive therapy (ECT) pulse amplitude, which dictates the induced electric field (E-field) magnitude in the brain, is presently fixed at 800 or 900 milliamperes (mA) without clinical or scientific rationale. We have previously demonstrated that increased E-field strength improves ECT's antidepressant effect but worsens cognitive outcomes. Amplitude-determined seizure titration may reduce the E-field variability relative to fixed amplitude ECT. In this investigation, we assessed the relationships among amplitude-determined seizure-threshold (STa), E-field magnitude, and clinical outcomes in older adults (age range 50 to 80 years) with depression. Subjects received brain imaging, depression assessment, and neuropsychological assessment pre-, mid-, and post-ECT. STa was determined during the first treatment with a Soterix Medical 4×1 High Definition ECT Multi-channel Stimulation Interface (Investigation Device Exemption: G200123). Subsequent treatments were completed with right unilateral electrode placement (RUL) and 800 mA. We calculated Ebrain defined as the 90th percentile of E-field magnitude in the whole brain for RUL electrode placement. Twenty-nine subjects were included in the final analyses. Ebrain per unit electrode current, Ebrain/I, was associated with STa. STa was associated with antidepressant outcomes at the mid-ECT assessment and bitemporal electrode placement switch. Ebrain/I was associated with changes in category fluency with a large effect size. The relationship between STa and Ebrain/I extends work from preclinical models and provides a validation step for ECT E-field modeling. ECT with individualized amplitude based on E-field modeling or STa has the potential to enhance neuroscience-based ECT parameter selection and improve clinical outcomes.

Ecological validity in neurocognitive assessment: Systematized review, content analysis, and proposal of an instrument

OBJECTIVES

The main objectives of this study are to identify the dimensions of Ecological Validity (EV) within the definitions of this concept, understand how they are operationalized in neurocognitive tests, and propose a checklist for EV attributes in neurocognitive tests.

METHOD

A systematized review was combined with content analysis of the selected papers, using the inductive method. We analyzed 82 studies on the EV of neurocognitive tests, 19 literature reviews and 63 empirical studies. Based on this review, we identified the relevant criteria for evaluating EV.

RESULTS

EV is a multidimensional concept with two main dimensions: representativeness and generalization. Representativeness involves the subdimensions simplicity-complexity and artificial-natural and several criteria organized on a continuum from low EV to high EV. Generalization is dependent on representativeness and is influenced by different cognitive and non-cognitive factors. We propose six stages for operationalizing EV, from defining the objectives of the neurocognitive assessment to the methodology for scoring and interpreting the results.

CONCLUSION

This systematized review helps to operationalize the concept of EV by providing a tool for evaluating and improving EV while developing new tests. Further studies with a longitudinal design can compare the predictive value of tests with higher versus lower EV-checklist scores.Key pointsQuestion: Understand the definition of EV, its dimensions and subdimensions, how EV is operationalized in neurocognitive tests and propose a checklist for the EV attributes of neurocognitive tests.Findings: The primary findings were that representativeness and generalization are the main dimensions of EV. Representativeness involves several subdimensions, whereas generalization is dependent on representativeness and is influenced by cognitive and non-cognitive factors. We provided an EV-checklist organized into six parts.Importance: The EV-checklist can be used to guide the development of ecologically valid neurocognitive tests and/or assess the EV of existing ones.Next steps: Examine the predictive value of tests that have higher EV-checklist scores.

Early identification of subjective cognitive functional decline among patients with Parkinson's disease: a longitudinal pilot study

Practical methods for early identification of Parkinson's disease (PD) mild cognitive impairment (PD-MCI) through changes in real-life daily functioning are scarce. The aim of the study was to examine whether the cognitive functional (CF) feature, comprising of seven self-reported Movement Disorder Society's (MDS) Unified Parkinson's Disease Rating Scale (UPDRS) items, predicts PD patients' cognitive functional status after a year. We conducted a 1-year follow-up of 34 PD patients (50-78 year; 70.6% men) suspected of MCI using the following measures: the MDS-UPDRS, UPDRS-CF feature, Beck Depression Inventory (BDI), Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT), Parkinson's Disease Cognitive Functional Rating Scale (PD-CFRS), and Daily Living Questionnaire (DLQ). The first and second UPDRS-CF feature scores, and additional measures at the 1-year follow-up significantly correlated. Hierarchical regression revealed that the initial MoCA, TMT, and BDI scores predicted the second UPDRS-CF, and the first UPDRS-CF predicted 31% of the second PD-CFRS score variance. Depression moderated the relationship between the first UPDRS-CF score and the DLQ Part A. These results suggest practical, self-reported, daily functional markers for identifying gradual decline in PD patients. They consider the patients' heterogeneity, underlying cognitive pathology, and implications on daily functioning, health, and well-being.

Capturing daily-life executive impairments in adults: Does the choice of neuropsychological tests matter?

OBJECTIVE

Standardized executive functioning (EF) measures do not reliably capture EF-related difficulties reported in daily life. We aim to determine if an ecologically relevant neuropsychological battery is more strongly associated with self-reported everyday EF impairments than classically used tests.

METHOD

Fifty-nine adults aged 18-49 self-rated their EF abilities using the Barkley Deficits in EF Scale (BDEFS) and were randomly assigned to complete either a test battery composed of EF measures with hypothesized ecological relevance (Six Elements, Zoo Map, Hayling Sentence Completion, Iowa Gambling, and Auditory Startle Tasks) or one composed of traditional EF tasks (Card Sorting, Trail Making, Color-Word Interference, and Verbal Fluency). Associations were examined using linear regression.

RESULTS

There were no strong associations between BDEFS subscales and performance on either test battery. Only the regression model predicting Emotional Regulation from ecological tasks was significant. Iowa Gambling Task performance and corrugator muscle contraction in the Auditory Startle Task individually contributed significantly to the model, with small and moderate effect sizes respectively.

CONCLUSION

Results align with evidence that self-reported EF difficulties are not adequately captured by formal neuropsychological measures, even for performance-based measures which directly tap everyday constructs. Findings are interpreted cautiously in the context of a small, high-functioning sample.

Rates of Cognitive and Functional Impairments in Older Adults Residing in a Continuing Care Senior Housing Community

OBJECTIVE

The current cross-sectional study examined cognition and performance-based functional abilities in a continuing care senior housing community (CCSHC) that is comparable to other CCSHCs in the US with respect to residents' demographic characteristics.

METHOD

Participants were 110 older adult residents of the independent living unit. We assessed sociodemographics, mental health, neurocognitive functioning, and functional capacity.

RESULTS

Compared to normative samples, participants performed at or above expectations in terms of premorbid functioning, attention span and working memory, processing speed, timed set-shifting, inhibitory control, and confrontation naming. They performed below expectation in verbal fluency and verbal and visual learning and memory, with impairment rates [31.4% (>1 SD below the mean) and 18.49% (>1.5 SD below the mean)] well above the general population (16% and 7%, respectively). Within the cognitive test battery, two tests of delayed memory were most predictive of a global deficit score. Most cognitive test scores correlated with performance-based functional capacity.

CONCLUSIONS

Overall, results suggest that a subset of older adults in the independent living sector of CCSHCs are cognitively and functionally impaired and are at risk for future dementia. Results also argue for the inclusion of memory tests in abbreviated screening batteries in this population. We suggest that CCSHCs implement regular cognitive screening procedures to identify and triage those older adults who could benefit from interventions and, potentially, a transition to a higher level of care.

Physical activity moderates the association between executive function and functional connectivity in older adults

Recent evidence suggests that physical activity may influence the functional connectivity of the aging brain. The purpose of this study was to examine the influence of physical activity on the association between executive function and functional connectivity of key brain networks and graph theory metrics in community-dwelling older adults. Participants were 47 older adults (M = 73 years; SD = 5.92) who participated in neuropsychological testing, physical activity measurements, and magnetic resonance imaging (MRI). Seed-to-voxel moderation analyses and graph theory analyses were conducted. Physical activity was significantly positively associated with default mode network functional connectivity (DMN FC; Posterior Cingulate Gyrus, p-FDR = 0.005; Frontal Pole (L), p-FDR = 0.005; Posterior Cingulate Gyrus, p-FDR = 0.006; Superior Frontal Gyrus (L), p-FDR = 0.016) and dorsal attention network functional connectivity (DAN FC; Inferior Frontal Gyrus Pars Opercularis (R), p-FDR = 0.044). The interaction between physical activity and executive function on the DMN FC and DAN FC was analyzed. The interaction between executive function and physical activity was significantly associated with DMN FC. When this significant interaction was probed, the association between physical activity and DMN FC differed between levels of high and low executive function such that the association was only significant at levels of high executive function. These results suggest that greater physical activity in later life is associated with greater DMN and DAN FC and provides evidence for the importance of physical activity in cognitively healthy older adults.

Cognitive profiles in older males and females

Males and females are subject to differences in cognitive processing strategies, i.e. the way males and females solve cognitive tasks. So far primarily reported for younger adults, this seems to be especially important in older adults, who also show sex differences in cognitive impairments. Therefore, the aim of the current study was to examine the older adult population with respect to cognitive profiles derived from a large variety of cognitive functions. Using an exploratory component analysis with consecutive confirmatory factor analysis in a sample of 676 older adults, neuropsychological performance data in a variety of cognitive domains was decomposed into cognitive components. A general cognitive profile based on the whole group fits unequally well on the two sexes. Importantly, cognitive profiles based on either males or females differ in terms of their composition of cognitive components, i.e. three components in males versus four components in females, with a generally better model fit in females. Thus, related to the established differences in processing styles between males and females the current study found a rather decomposed (or local) cognitive profile in females while males seem to show a holistic (or global) cognitive profile, with more interrelations between different cognitive functions.

Interpreting executive and lower-order error scores on the timed subtests of the Delis-Kaplan Executive Function System (D-KEFS) battery: Error analysis across the adult lifespan

OBJECTIVE

The Delis-Kaplan Executive Function System (D-KEFS) is a battery of tests designed to measure executive functions (EF). Additionally, the D-KEFS contains lower-order tasks, designed to control for speed of visual scanning, sequencing, and verbal and graphomotor output. The construct and criterion validities of D-KEFS scores that are time-based are well established. However, the constructs measured by the D-KEFS error scores are poorly understood, making clinical interpretations of such scores difficult. This study examined the construct validity of D-KEFS errors committed on EF tasks and tasks designed to measure lower-order processes (i.e., non-EF tasks), across the adult lifespan.

METHOD

Participants were 427 adults (18-93 years) who completed the timed subtests of the D-KEFS. Four hundred two participants also completed the Push-Turn-Taptap (PTT; a separate measure of EF) to allow cross-validation.

RESULTS

General linear regressions showed that D-KEFS errors committed on the EF tests were associated with EF timed performance (assessed using the D-KEFS time-based scores and the PTT), but only among older adults. Importantly, errors committed on the D-KEFS tasks of lower-order processes were also associated with D-KEFS time-based EF performance, and this relationship held across the adult lifespan.

CONCLUSIONS

These findings suggest that among older adults EF errors on the D-KEFS can be interpreted as indices of EF, but such interpretations are not automatically warranted for younger adults. Additionally, errors committed on non-EF tasks contained within the D-KEFS battery can be interpreted as reflecting EF weaknesses across the adult lifespan.

CHA2DS2-VASc Stroke Risk Index and Executive Functioning in Older Adults

OBJECTIVE

CHA2DS2-VASc is a stroke risk classification system developed to improve the precision of stroke risk classification. The current study examined the validity of CHA2DS2-VASc in a sample of healthy older adults using executive function measures of processing speed, working memory, and cognitive flexibility that are sensitive to cerebrovascular risk factors.

METHODS

Participants included 51 community-dwelling, healthy older adults (ages 53-86) recruited from both the community and cardiology clinics. CHA2DS2-VASc was utilized as a measure of stroke risk. Measures of executive functioning and processing speed included the Paced Auditory Serial Addition Test (PASAT), Delis-Kaplan Executive Function System (DKEFS) Number-Letter Switching, and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Coding.

RESULTS

CHA2DS2-VASc scores significantly predicted scores on the PASAT, DKEFS Number-Letter Switching, and RBANS Coding, such that greater stroke risk was associated with poorer performances on tests of executive functioning and processing speed. These relationships were observed over and above the potential influence of educational attainment and symptoms of depression.

CONCLUSION

Significant relations between stroke risk classification and performance on several measures of executive functioning provide support for a wider and more generalized use of CHA2DS2-VASc with healthy older adults. These findings further highlight the importance of early identification and treatment of stroke risk factors associated with cognitive decline. Findings suggest that CHA2DS2-VASc is a practical and useful tool for patients and their providers in the early detection of stroke risk and development of individualized treatment plans.

Executive function moderates naltrexone effects on methamphetamine-induced craving and subjective responses

Background: Emerging evidence suggests that opioid receptor antagonists, such as naltrexone, are effective pharmacotherapies for alcohol, opioid, and possibly stimulant use disorders. It is posited that naltrexone exerts its effects, in part, by increasing functional connectivity between neural reward circuitry and frontal systems implicated in executive function. Yet no studies had examined whether executive function moderates these effects. Objectives: This study examined whether a composite measure of executive function (EF) moderates the effect of naltrexone on craving for methamphetamine and subjective responses following infusion of the drug. Methods: Individuals with methamphetamine use disorder (N = 30; 27% female) completed baseline neurocognitive assessments of premorbid and executive function, and an executive function factor was computed. Participants then underwent a randomized, double-blind, cross-over study of titration with naltrexone and placebo. Participants then received a 30-mg intravenous methamphetamine infusion and completed subjective response questionnaires at 8 times in the 120 minutes post-infusion. Results: Multilevel mixed models indicated a significant EF × medication interaction, reflecting greater effects of naltrexone to decrease "desire to access the drug", "want more of the drug", "crave the drug", "feel drug effects" and "feel high" in participants with low EF compared to those with high EF (Bs = .36-1.29, SEs = .14-.17, ps<0.01). These effects remained significant after controlling for premorbid cognitive functioning, baseline responses to methamphetamine, severity of methamphetamine use, and methamphetamine-related functional problems. Conclusion: Naltrexone may be especially effective in methamphetamine-dependent individuals with low EF. Neuropsychological assessments may also provide predictive clinical utility not captured by traditional measures of substance use severity.

Association between anti-inflammatory interleukin-10 and executive function in African American women at risk for Alzheimer's disease

INTRODUCTION

African-Americans (AAs) are 64% more likely to be diagnosed with AD than non-Hispanic Whites. AAs with elevated AD biomarkers exhibit greater neurodegeneration in AD signature regions compared to non-Hispanic Whites with elevated AD biomarkers. This pilot trial examined whether normal or elevated plasma levels of interleukin (IL)-10 are associated with changes in executive function and short-term memory in AA women at risk for developing AD due to parental history.

METHOD

Observational study comparing groups with elevated and normal plasma IL-10 levels. Study included 31 AA women (age=58.9±8 years) with parental history of AD. Measures included inflammatory blood biomarkers, executive function and visuospatial short-term memory tests. Multivariate linear regression with adjustment for comorbidities, and Bonferroni corrections for multiple comparisons were used to compare groups. Effect sizes (Cohen's d) were generated. Using endpoints with moderate-large effects between groups, Pearson correlations determined associations between biomarker levels and cognitive performance.

RESULTS

The elevated IL-10 group performed worse on the Trail-Making Test proportional score ((B-A)/A) (effect size (d =-0.87 (-1.6, -.1)). Moderate effects with large confident intervals were noted in inhibition, set-switching, and body position spatial memory. Significant differences between groups in levels of other inflammatory markers were noted, including IL-7 (p=0.002) and interferon γ (p=0.02). IL-7 remained significant after Bonferroni correction. Correlation matrices revealed moderate-large, significant correlations (yet with wide confidence intervals) between levels of IL-10 and IL-9 with BPST total correct trials, and between interferon γ and delayed recall.

CONCLUSIONS

Interleukins may incite inflammation, leading to impaired aspects of executive function and short-term memory in this sample of African American women at risk for developing AD. This research provides effect sizes that will be used to power future research that will further investigate the relationship between inflammation, AD biomarkers, and cognitive function in an understudied population.

A Multi-method Investigation of the Personality Correlates of Functional Ability in Older Adults

OBJECTIVES

This study evaluated the role of personality in predicting functional ability (FA) in older adults using self-report, collateral report, and performance-based measures of FA.

METHODS

Participants included older adults (N = 131) who completed a personality measure (NEO-FFI), a self-report of FA (OARS ADL), and participated in a performance-based assessment of FA (DAFS-R). In addition, each participant had a collateral complete a collateral report of FA (OARS ADL). Bivariate correlations were computed to assess how Five Factor Model traits were related to self-report, collateral, and performance-based measures of FA.

RESULTS

Neuroticism was negatively related to self-reported FA (r = - .27) and collateral-reported FA (r = - .18) and Conscientiousness was positively related to self-reported FA (r = .25). None of the traits were significantly related to the performance-based measure of FA.

CONCLUSIONS

These results suggest that personality traits can impact self-reported FA in older adults and underscore the importance of assessing FA in older adults using multiple methods, particularly performance-based measures.

CLINICAL IMPLICATIONS

Clinicians should consider how personality may impact FA in older adults and multiple methods of FA performance should be examined to better tailor recommendations.

Predictors of instrumental activities of daily living in community-dwelling older adults

Psychiatric mental health clinicians often rely on proxy and self-report evaluations to determine the cognitive function of older adults however, performance measures have greater accuracy and predictive ability for everyday function. This study tested physical and cognitive predictors of functional abilities in fifty-one community residing older adults. We administered a computerized battery of executive function tasks, a performance-based measure of instrumental activities of daily living (IADL), and three physical function measures (grip strength, 30-second Chair Stand Test, and 8-foot Up and Go). Regression models assessed the associations of three components of executive function (updating, shifting, and inhibition) with IADLs and physical functions. Updating was a significant predictor of the Medications and Financial DAFS scores and of grip strength. Shifting also predicted grip strength. In conclusion, different executive functions predict different domains of IADL functioning. Working memory was a robust predictor of IADL functioning in older adults, especially medication management skills.

Naturally Occurring Expressive Suppression is Associated with Lapses in Instrumental Activities of Daily Living Among Community-Dwelling Older Adults

OBJECTIVES

Expressive suppression (i.e., effortful regulation of overt affect) has a deleterious impact on executive functioning (EF). This relationship has potential ramifications for daily functioning, especially among older adults, because a close relationship exists between EF and functional independence. However, past research has not directly examined whether expressive suppression impacts instrumental activities of daily living (IADL). The present study examined this association among older adults.

METHODS

One hundred ten community-dwelling older adults completed a self-report measure of acute (past 24 hr) and chronic (past 2 weeks) expressive suppression, a timed test of IADL, and the Behavioral Dyscontrol Scale as a measure of EF.

RESULTS

High chronic expressive suppression was related to slow IADL performance beyond covariates (age, IQ, depression), but only for individuals with low EF. High acute expressive suppression was associated with lower accuracy on IADL tasks beyond covariates (IQ, depression), but this association was fully explained by EF.

CONCLUSIONS

The current results suggest that expressive suppression is associated with less efficient and more error-prone IADL performance. EF fully accounted for the relationship between acute expressive suppression and IADL performance, showing that suppression is a risk factor for both poorer EF performance and functional lapses in daily life. Furthermore, individuals with weaker EF may be particularly vulnerable to the effect of chronic expressive suppression. (JINS, 2019, 25, 718-728).

A New Brief Measure of Executive Function: Adapting the Head-Toes-Knees-Shoulders Task to Older Adults

BACKGROUND AND OBJECTIVES

Executive function (EF) abilities are recognized as components of cognition most likely to show age-related declines. Measurement of EF in older adults is often computer-based, takes place in a laboratory setting, and thus lacks ecological validity. We sought to investigate a new way of measuring EF in older adults by adapting a brief, behavioral measure of EF in children, the Head-Toes-Knees-Shoulders task (HTKS).

RESEARCH DESIGN AND METHODS

A sample of 150 community-dwelling older adults (Mean age = 68.55, SD = 6.34) completed the HTKS, NIH Toolbox: Cognition Battery (NIHTB-CB) and Positive and Negative Affect Schedule.

RESULTS

The HTKS showed adequate internal consistency, α = .84. Significant associations between HTKS variables and measures of attention and inhibitory control were robust to the influences of age, processing speed, and subjective health ratings. HTKS completion time exhibited the strongest associations to NIHTB-CB measures, suggesting that the time it takes older adults to complete the HTKS may be a better measure of EF than the total score. Nonsignificant associations between HTKS variables and positive and negative affect demonstrated discriminant validity.

DISCUSSION AND IMPLICATIONS

These results provide initial evidence for use of the HTKS as a brief, low-cost, easy to administer measure of EF in older adults. Further research is needed to determine its potential to identify individuals at risk for poor cognitive outcomes. A brief, valid measure may allow for wider screenings aimed at early intervention, when cognitive interventions are most effective.

The weekly calendar planning activity in multiple sclerosis: A top-down assessment of executive functions

Deficits in executive functioning are detrimental to employment, daily functioning and quality of life, however their precise nature in multiple sclerosis (MS) remains underspecified. The aims of this study were to: (1) describe the executive processes affected in MS, using a top-down (Weekly Calendar Planning Activity; WCPA) and bottom-up (Delis-Kaplan Executive Function System; DKEFS) assessment tools; (2) explore relationships between performance on the WCPA and DKEFS with a test of everyday functional performance, Actual Reality^TM (AR). Methods: Sixty two participants with MS with and without cognitive impairments (n = 21 and 41, respectively) and 38 Healthy Controls (HC) completed the WCPA, two selected subtests of the DKEFS, and AR. Results: The MS group with cognitive impairments performed worse compared with the MS with no cognitive impairments and HC on both the WCPA and DKEFS. Better scores on the DKEFS were associated with better performance of the WCPA. WCPA was a significant predictor of three of the four AR variables. The DKEFS was a significant predictor of time to perform the AR. The results support the use of the WCPA as an assessment of executive functions in persons with MS. It embodies processes such as environmental monitoring, planning and problem solving, and self-regulation.

Executive dysfunction in neuro-oncology: Behavior Rating Inventory of Executive Function in adult primary brain tumor patients

Adult primary brain tumor (PBT) survivors report persistent cognitive difficulties before, during, and after treatment, which are problematic for everyday functioning. Cognitive domains often affected by cancer treatment appear to be attention and executive functioning (EF). One validated measure developed to assess an individual's EF within daily living is the Behavior Rating Inventory of Executive Function-Adult (BRIEF-A). To date, no published research has investigated the EF profile of PBT patients using the BRIEF-A. Seventy-four PBT patients completed the BRIEF-A. Descriptive analyses were conducted to determine the self-reported EF profile in PBT patients. T-tests preliminarily compared the performance of PBT patients to four other comparison groups: mild cognitive impairment (MCI; n = 23), attention-deficit/hyperactivity disorder-unmedicated (ADHD-U; n = 27), traumatic brain injury (TBI; n = 23), and healthy controls (HC; n = 26). PBT BRIEF-A group means were average across subscales and indexes, yet the prevalence of significant elevations ranged from 12 to 50%. The Metacognition Index demonstrated 38% elevation prevalence compared to 22% in Behavioral Regulation. Approximately 61% of the sample had at least one clinically elevated scaled score. PBT patients reported significantly more EF impairment than HC and significantly less than ADHD-U. No significant differences were found between the PBT and MCI groups or PBT and TBI groups. Despite group means not reaching clinical impairment, a substantial proportion of patients with PBTs endorse executive dysfunction. Elevations were most prominent in metacognitive abilities over behavioral dysregulation. Notably, the EF profile of PBT patients was remarkably similar to that of MCI and TBI, increased when compared to HC, and well below ADHD-U.

Parent depressive symptoms and offspring executive functioning

Introduction: Previous research has found mixed results when assessing the association between a parent's history of depressive symptoms and a child's abilities on measures of executive functioning. The purpose of this study was to replicate and expand upon these findings by evaluating the influence of a parent's depressive symptoms on a young person's executive functioning. Method: As part of a larger study, 135 children (54.8% female, aged 8-12) and one biological parent completed diagnostic screening interviews. Children then completed a brief executive functioning battery. Symptoms endorsed under the past major depressive episode module of the MINI International Neuropsychiatric Interview was used to measure depressive symptoms of parents. Results: While controlling for parent alcohol status and age, gender, intelligence, and current depressive symptoms of the child, linear regression models revealed that the parent's depressive symptoms significantly predicted deficits in Letter-Number Sequencing [b = -0.15 (0.07), p < .05] and Motor Speed [b = -0.17 (0.05), p < .005] on the Delis-Kaplan Executive Function System (D-KEFS) Trails Test. Parent depressive symptoms had no relationship with inhibition on the D-KEFS Color-Word Interference Test [b = -0.04 (0.14), p = .74] or the Verbal Working Memory subtest of the Stanford-Binet [b = 0.14 (0.12) p = .43]. Greater depressive symptoms in parents were associated with fewer perseverative errors on the Wisconsin Card Sorting Task (WCST) [b = 0.73 (0.32), p < .05]. Conclusion: In sum, a parent's depressive symptomatology was differentially associated with a young person's neurocognitive abilities. Clinical implications were discussed.

Item response theory analyses of the Delis-Kaplan Executive Function System card sorting subtest

In the current study, we examined the dimensionality of the 16-item Card Sorting subtest of the Delis-Kaplan Executive Functioning System assessment in a sample of 264 native English-speaking children between the ages of 9 and 15 years. We also tested for measurement invariance for these items across age and gender groups using item response theory (IRT). Results of the exploratory factor analysis indicated that a two-factor model that distinguished between verbal and perceptual items provided the best fit to the data. Although the items demonstrated measurement invariance across age groups, measurement invariance was violated for gender groups, with two items demonstrating differential item functioning for males and females. Multigroup analysis using all 16 items indicated that the items were more effective for individuals whose IRT scale scores were relatively high. A single-group explanatory IRT model using 14 non-differential item functioning items showed that for perceptual ability, females scored higher than males and that scores increased with age for both males and females; for verbal ability, the observed increase in scores across age differed for males and females. The implications of these findings are discussed.

Moderators of age effects on attention bias toward threat and its association with anxiety

OBJECTIVE

The current study used a research domain criteria (RDoC) approach to assess age differences in multiple indicators of attention bias and its ties to anxiety, examining stimulus domain and cognitive control as moderators of older adults' oft-cited positivity effect (bias towards positive and away from negative stimuli, when compared to younger adults).

METHOD

38 Younger adults and 38 older adults were administered a battery of cognitive control and trait and state anxiety measures, and completed a dot-probe task to assess attention bias, during which reaction time and fixation duration (using eye-tracking) were recorded for negative and neutral social (a salient threat domain for younger adults) and physical (a salient threat domain for older adults) stimuli.

RESULTS

Mixed-effects models demonstrated that older adults were faster to react to dot-probe trials when the probe appeared in the place of negative (vs. neutral) physical stimuli, but displayed no difference in reaction time for social stimuli. Also, older (vs. younger) adults with lower levels of cognitive control were less negatively biased in their visual fixation to social stimuli. A negative reaction time attention bias on the dot-probe task predicted greater trait anxiety among participants with low levels of cognitive control, with a more complex pattern predicting state anxiety.

CONCLUSION

Older adults do attend to social and physical stimuli differently. When stimuli concern a social threat, older adults do not preferentially attend to either neutral or negative stimuli. However, when stimuli concern physical threat, older adults preferentially attend to negative stimuli. Threat biases are associated with anxiety at all ages for those with low cognitive control.

Accuracy statistics in predicting Independent Activities of Daily Living (IADL) capacity with comprehensive and brief neuropsychological test batteries

This investigation was designed to determine the predictive accuracy of a comprehensive neuropsychological and brief neuropsychological test battery with regard to the capacity to perform instrumental activities of daily living (IADLs). Accuracy statistics that included measures of sensitivity, specificity, positive and negative predicted power and positive likelihood ratio were calculated for both types of batteries. The sample was drawn from a general neurological group of adults (n = 117) that included a number of older participants (age >55; n = 38). Standardized neuropsychological assessments were administered to all participants and were comprised of the Halstead Reitan Battery and portions of the Wechsler Adult Intelligence Scale-III. A comprehensive test battery yielded a moderate increase over base-rate in predictive accuracy that generalized to older individuals. There was only limited support for using a brief battery, for although sensitivity was high, specificity was low. We found that a comprehensive neuropsychological test battery provided good classification accuracy for predicting IADL capacity.

Expressive Suppression Depletes Executive Functioning in Older Adulthood

OBJECTIVES

Accurate detection of executive dysfunction in neuropsychological assessments is complicated by the fact that executive functioning (EF) is vulnerable to temporary disruption (i.e., lapses), with more frequent lapses in older adulthood. Effortful regulation of affect (i.e., expressive suppression) is a well-known source of executive lapses in younger adults, but the generalizability of this depleting effect to older adults is unknown. The purpose of this study was to (1) determine whether EF is subject to depletion via expressive suppression and (2) to examine whether this effect is unique to EF, or whether it also applies to lower-order component processes in older adults.

METHODS

Ninety-seven non-demented, community-dwelling older adults were randomly assigned to either an expressive suppression group or control group. We compared performance of the groups on a battery of tests measuring EF and component processes both before and after exposure to emotionally evocative stimuli.

RESULTS

Consistent with the hypothesized depletion effect, suppressing participants showed an attenuated practice effect on post-manipulation EF relative to controls, while performance on lower-order component processes was unaffected by suppression.

CONCLUSIONS

These results suggest that depletion contributes to executive lapses in older adulthood. (JINS, 2017, 23, 341-351).

Phishing suspiciousness in older and younger adults: The role of executive functioning

Phishing is the spoofing of Internet websites or emails aimed at tricking users into entering sensitive information, with such goals as financial or identity theft. The current study sought to determine whether age is associated with increased susceptibility to phishing and whether tests of executive functioning can predict phishing susceptibility. A total of 193 cognitively intact participants, 91 younger adults and 102 older adults, were primarily recruited through a Psychology department undergraduate subject pool and a gerontology research registry, respectively. The Executive Functions Module from the Neuropsychological Assessment Battery and the Iowa Gambling Task were the primary cognitive predictors of reported phishing suspiciousness. Other predictors included age group (older vs. younger), sex, education, race, ethnicity, prior knowledge of phishing, prior susceptibility to phishing, and whether or not browsing behaviors were reportedly different in the laboratory setting versus at home. A logistic regression, which accounted for a 22.7% reduction in error variance compared to the null model and predicted phishing suspiciousness with 73.1% (95% CI [66.0, 80.3]) accuracy, revealed three statistically significant predictors: the main effect of education (b = 0.58, SE = 0.27) and the interactions of age group with prior awareness of phishing (b = 2.31, SE = 1.12) and performance on the Neuropsychological Assessment Battery Mazes test (b = 0.16, SE = 0.07). Whether or not older adults reported being suspicious of the phishing attacks used in this study was partially explained by educational history and prior phishing knowledge. This suggests that simple educational interventions may be effective in reducing phishing vulnerability. Although one test of executive functioning was found useful for identifying those at risk of phishing susceptibility, four tests were not found to be useful; these results speak to the need for more ecologically valid tools in clinical neuropsychology.

Assessment of Activities of Daily Living, Self-Care, and Independence

Activities of daily living (ADL) comprise the basic actions that involve caring for one's self and body, including personal care, mobility, and eating. In this review article, we (1) review useful clinical tools including a discussion on ways to approach ADL assessment across settings, (2) highlight relevant literature evaluating the relationship between cognitive functioning and ADLs, (3) discuss other biopsychosocial factors affecting ADL performance, (4) provide clinical recommendations for enhancing ADL capacity with an emphasis on self-care tasks (eating, grooming, dressing, bathing and toileting), and (5) identify interventions that treatment providers can implement to reduce the burden of ADL care.

Functional Disability in Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

Accumulating evidence suggests that the pre-dementia syndrome mild cognitive impairment (MCI) is characterized by decrements in instrumental activities of daily living (IADL). The current review was a quantitative synthesis of the available literature to objectively characterize IADL disability in MCI while clarifying inconsistencies in findings across studies. It was hypothesized that individuals with MCI would display significantly greater functional impairment relative to cognitively intact controls. Candidate moderators specified a priori included functional assessment approach, MCI subtype, depressive symptoms, and language conducted. Online databases (PubMed/MEDLINE and PsycINFO) and reference lists were searched to identify peer-reviewed publications assessing IADL in MCI compared to normal aging. A total of 151 effect sizes derived from 106 studies met inclusionary criteria (N = 62,260). Random effects models yielded a large overall summary effect size (Hedges' g = 0.76, 95 % confidence interval: 0.68 - 0.83, p < .001) confirmed in multi-level analyses adjusted for nesting of effect sizes within studies (g = 0.78, 95 % confidence interval: 0.69 - 0.87). Functional assessment strategy and MCI subtype were significant moderators of effect size, whereas depressive symptoms and language were not. Results convincingly demonstrate that MCI is associated with significant difficulties in the performance of complex everyday tasks. It appears that functional decline, like cognitive decline, exists on a continuum from healthy aging to dementia onset. Implications for clinical practice and research priorities are discussed.

The Effects of Preresponse Cues on Inhibitory Control and Response Time in Adults With ADHD

OBJECTIVE

The purpose of this study was to examine the effects of preresponse cues on behavioral control in adults with ADHD.

METHOD

Eighty-eight adults with ADHD and 67 adults with no history of ADHD completed a cued go/no-go task. This task requires participants to respond or inhibit a response to go and no-go targets, respectively, and preresponse cues provide participants with predictive information about the upcoming target.

RESULTS

Overall, participants with ADHD made more inhibitory failures and responded more slowly than controls. These group differences were only present in the valid-cue condition, and there were no significant group differences in the invalid-cue conditions.

CONCLUSION

These findings suggest that adults with ADHD are less able to utilize predictive environmental information to facilitate behavioral control.

Personality's association with IADLs in community dwelling older adults

OBJECTIVES

Extant research has established several predictors of functional ability (FA) in older adults (OAs); however, one factor that has been relatively ignored is personality. Preliminary evidence suggests that openness and agreeableness are associated with instrumental activities of daily living (IADLs). However, how personality is related to IADLs remains unclear. We aimed to determine how personality factors predict performance of IADLs, which we hypothesized, was because of executive functioning (EF).

METHODS

To best understand the relationship between personality and IADLs, we recruited and ran 65 independent community dwelling OAs. Bivariate correlations and hierarchical regressions were completed to determine the associations between openness and agreeableness with IADLs. Lastly, mediation analyses were completed to examine our hypothesis that EF would mediate this relationship

RESULTS

Correlation and regression findings support the relationship between openness and IADLs but not agreeableness and IADLs. As hypothesized, the relationship between openness and IADLs was mediated by EF.

CONCLUSIONS

We replicated the relationship between openness and IADLs and extend the literature by showing the mechanism of action for this relationship is EF. While our mediation results support this perspective, future research should determine if interventions that increase OAs' EF, in turn, increase or attenuate decline in IADLs over time.

Telephone-based goal management training for adults with mild traumatic brain injury: study protocol for a randomized controlled trial

BACKGROUND

Approximately 1 million individuals experience a mild traumatic brain injury (TBI) and cost the United States nearly $17 billion each year. Many trauma survivors with mild TBI have debilitating and long-term physical, emotional, and cognitive impairments that are unrecognized at trauma centers. Early intervention studies are needed to address these impairments, especially cognitive deficits in executive functioning. Goal management training (GMT) is a structured cognitive rehabilitation program that has been found to improve executive functioning in patients with moderate to severe TBI. The current study adapted the GMT program for telephone delivery in order to improve the accessibility of rehabilitation services in a patient population with multiple barriers to care and significant yet unrecognized cognitive impairment. The primary objective of this study is to examine the efficacy of telephone-based GMT for improving executive functioning, functional status, and psychological health in trauma survivors with mild TBI.

METHODS/DESIGN

This study is a three-group randomized controlled trial being conducted at a Level I trauma center. Ninety trauma survivors with mild TBI and cognitive deficits in executive functioning will be randomized to receive telephone-based GMT, telephone-based education, or usual care. GMT and education programs will be delivered by a physical therapist. The first in-person session is 1 h and the remaining six telephone sessions are 30 min. A battery of well-established cognitive tests will be conducted and validated questionnaires will be collected that measure executive functioning, functional status, and depressive and posttraumatic stress disorder symptoms at 6 weeks, 4 months, and 7 months following hospital discharge.

DISCUSSION

This study supports a telephone-delivery approach to rehabilitation services in order to broaden the availability of evidence-based cognitive strategies.

TRIAL REGISTRATION

This trial was registered with Clinicaltrials.gov on 10 October 2012, registration number: NCT01714531.

The relationship between cognitive reserve and functional ability is mediated by executive functioning in older adults

It has been noted in the literature that cognitive reserve (CR) predicts future functional ability (FA), but the association between CR and current FA is rather limited. This investigation aimed to explicate this relationship, and hypothesized it would be mediated by executive functioning (EF). To best understand the relationship between CR and FA, we recruited and tested independent community-dwelling older adults (OAs). Bivariate correlations and hierarchical regressions were completed to determine the association between CR and FA. Both individual CR measures and a composite CR score were used. Mediation analyses were completed to examine our hypothesis that EF would mediate the CR and FA relationship. All measures of CR were positively related to and predictive of FA. Although the highest zero-order correlation across the independent CR proxies was between income and FA (r = .417), education accounted for the greatest amount of variance in FA, 8.3% after controlling for age and Mini-Mental State Examination performance. Furthermore, the CR composite had a higher correlation (r = .447) and accounted for more variance than any of the independent proxies. Complete mediation was found between a CR composite and FA via an internally consistent D-KEFS composite score (Cronbach's α = .795). This suggests that as CR increases so does EF, which in turn improves FA. Thus, future investigations could determine the effect on FA in OAs by improving EF.

Functional impairment in mild cognitive impairment evidenced using performance-based measurement

Older adults (OAs) with mild cognitive impairment (MCI) are traditionally thought to have preservation of activities of daily living (ADLs). However, recent evidence suggests OAs with MCI may have difficulty completing ADLs and specifically instrumental ADLs (IADLs). The ADLs are frequently evaluated through self- or collateral report questionnaires, while performance-based measures are infrequently utilized, despite the decreased bias and increased accuracy and sensitivity associated with these instruments. This investigation compared ADLs between community-dwelling OAs with (n = 20) and without MCI (n = 30) using a self-report questionnaire (Older American Resources and Services Activities of Daily Living Scale; OARS), a collateral report questionnaire (OARS), and a performance-based measure (the Direct Assessment of Functional Status-Revised). Consistent with our hypothesis, OAs with MCI had decreased ADLs and IADLs on the performance-based measure compared to cognitively intact OAs, while there were no differences in ADLs or IADLs on self-report questionnaires or collateral report questionnaires. Our results suggest OAs with MCI have decreased ability to complete IADLs. However, this investigation suggests these deficits may not be detected by questionnaires and are more likely to be found with performance-based testing.

Reliability and validity of the Executive Interview (EXIT) and Quick EXIT among community dwelling older adults

OBJECTIVES

To investigate the psychometric properties of the Executive Interview (EXIT) and Quick EXIT in community dwelling older adults.

DESIGN

Secondary analysis of data obtained as part of a longitudinal study of cognitive function in late-life depression.

SETTING

A university hospital.

PARTICIPANTS

Community-dwelling adults (N = 422), aged 59 years and older, with current or recent history of non-psychotic unipolar major depression, and never-depressed comparison subjects.

MEASUREMENTS

The EXIT and other measures of executive control functions (ECF), non-executive cognitive domains, and global cognitive function. We calculated Quick EXIT scores from the EXIT.

RESULTS

The EXIT demonstrated high inter-rater reliability (Intraclass correlation coefficient = 0.978, F(7, 21) = 174.85, p <0.001), and both the EXIT and Quick EXIT demonstrated moderate internal consistency (α = 0.66 and α = 0.68, respectively). Both tests also demonstrated acceptable convergent validity against several standard tests of ECF (rs -0.399 to 0.322, except for the Trail Making Test B, where rs was 0.057 to 0.063) as well as against measures of multifactorial cognitive function (rs -0.432 to 0.491). Both tests, however, demonstrated inconsistent discriminant validity against a variety of standard non-ECF tests (rs -0.013 to 0.376).

CONCLUSIONS

Both the EXIT and the Quick EXIT have adequate reliability and appear to require ECF in this population. However, both the EXIT and the Quick EXIT also reflect non-ECF domains. The EXIT and Quick EXIT should be considered to be measures of global cognitive function rather than pure ECF measures. Given similar reliability and validity, the Quick EXIT is recommended clinically as it is briefer and less burdensome than the full EXIT.

Ten-year longitudinal trajectories of older adults' basic and everyday cognitive abilities

OBJECTIVE

To examine the longitudinal trajectories of everyday cognition and longitudinal associations with basic (i.e., laboratory and experimentally measured) cognitive abilities, including verbal memory, inductive reasoning, visual processing speed, and vocabulary.

METHOD

Participants were healthy older adults drawn from the no-treatment control group (N = 698) of the Advanced Cognitive Training for the Independent and Vital Elderly (Willis et al., 2006) randomized trial and were assessed at baseline and 1, 2, 3, 5, and 10 years later. Analyses were conducted using latent growth models.

RESULTS

Modeling revealed an overall inverted-U shape (quadratic) trajectory across cognitive domains. Among basic cognitive predictors, level and slope in reasoning demonstrated the closest association to level and slope of everyday cognition, and accounted for most of the individual differences in linear gain in everyday cognition.

CONCLUSION

Everyday cognition is not buffered against decline, and is most closely related to inductive reasoning in healthy older adults. To establish the clinical utility of everyday cognitive measures, future research should examine these associations in samples with more cognitive impairment.

Cognitive reserve moderates relation between global cognition and functional status in older adults

The ability to perform instrumental activities of daily living (IADLs) is necessary for independent living. Research suggests that community-dwelling older adults are at risk for experiencing subtle decrements in the performance of IADLs. Neuropsychological tests have been used to account for differences in IADL status. Studies of the relationship between cognitive ability and functional status have produced variable results, however, and cognitive ability appears to be only a moderate predictor. Several studies of normal aging have revealed cognitive and functional benefits of higher cognitive reserve (CR) in healthy, nondemented older adults. The purposes of the present study were to: (a) examine the relationship between global cognitive ability and IADL performance among 53 community-dwelling older adults, and (b) determine whether formal education, as a proxy of CR, significantly moderates this relationship. Consistent with previous findings, global cognitive ability accounted for a considerable portion of variance in IADL performance [ΔR(2) = .54; ΔF(2, 53) = 67.96; p < .001]. Additionally, CR modestly but significantly attenuated this relationship [ΔR(2) = .044; ΔF(4, 53) = 5.98; p = .018; total R(2) = .65]. This finding suggests that community-dwelling older adults with lower levels of formal education may be at greater risk for functional decrements associated with age-related cognitive decline.

New approaches to understand cognitive changes associated with chemotherapy for non-central nervous system tumors

CONTEXT

Researchers have described a constellation of cognitive deficits (e.g., impairments in executive functions, working memory, attention, and information-processing speed) associated with cancer treatment, and specifically chemotherapy, for non-central nervous system tumors. However, findings have been inconsistent, largely because of measurement and study design issues.

OBJECTIVES

To propose ways for researchers to more clearly delineate and characterize the mild cognitive deficits and related outcomes that appear to affect a subset of cancer patients and suggest methods to make more effective use of the existing data to understand risk factors for impaired neuropsychological functioning.

METHODS

We examined the literature on the relationship between chemotherapy and cognitive impairment, as well as related literature on neuropsychological measurement, structural and functional neuroimaging, alternative measures of health outcomes, and integrative data analysis.

RESULTS

A more comprehensive picture of cognitive functioning might be obtained by incorporating nontraditional ecological measures, self-reports, computational modeling, new neuroimaging methods, and markers of occupational functioning. Case-control and integrative data analytic techniques potentially could leverage existing data to identify risk factors for cognitive dysfunction and test hypotheses about the etiology of these effects.

CONCLUSION

There is a need to apply new research approaches to understand the real-world functional implications of the cognitive side effects of chemotherapy to develop and implement strategies to minimize and remediate these effects before, during, and after cancer treatment.

Neurobehavioral profiles in individuals with hyperimmunoglobulin E Syndrome (HIES) and brain white matter hyperintensities

PURPOSE

Individuals with hyperimmunoglobulin E Syndrome (HIES) have central nervous system abnormalities, including focal white matter hyperintensities (WMH), or unidentified bright objects. This cross-sectional study aimed to describe the cognitive and emotional functioning and quality of life of people with HIES. We also sought to explore the relationship between cognitive functioning and WMHs in this population.

METHODS

Twenty-nine individuals (13 males) with autosomal-dominant HIES (mean age = 35.1 years, range 16-55) were administered a comprehensive psychological assessment as part of a natural history protocol. The assessment included measures of global cognitive functioning (Wechsler Adult Intelligence Scale-III), memory (California Verbal Learning Test-II, Wechsler Memory Scale-III), executive skills (Delis Kaplan Executive Function System), and attention (Test of Everyday Attention). Emotional symptoms and quality of life also were assessed.

RESULTS

All mean cognitive scores were within normal limits. Mean scores on memory and executive functioning measures were significantly lower than Full Scale IQ scores (ps < .05). Substantial percentages of patients self-reported executive skills to be in the clinical range. Patients with fewer (1-20) versus more (21+) WMHs scored significantly better on measures of global cognitive skills, visual-perceptual skills, and working memory. Mean scores on emotional symptom and quality of life measures were in the average range and unrelated to WMHs.

CONCLUSIONS

Global cognitive functioning was average to high average in our sample of individuals with HIES. However, focal brain lesions were associated with lower scores in specific domains. Emotional functioning and quality of life are within normal limits in this sample.

Executive functioning in schizophrenia: the result of impairments in lower order cognitive skills?

Executive functioning (EF) impairments are common in schizophrenia. There are two propositions regarding the causes of these impairments: (1) executive impairments are the result of the compounding effects of deficits in lower order cognitive skills (e.g. processing speed, attention) or (2) EF impairments exist in their own right regardless of lower order skills. It is difficult to examine the separable effects of lower order cognitive skills on EF given the overlap required to complete most neuropsychological measures. One battery designed to parcel out the contributions of lower order skills from EF is the Delis-Kaplan Executive Function System (D-KEFS). Inhibition and switching specifically were examined using the D-KEFS versions of the Stroop and Trails task. No group differences in task performance after controlling for lower level skills would provide evidence for a generalised cognitive deficit. Group differences remaining after controlling for these influences would suggest a disproportionate deficit. Results supported both propositions. On both tasks, group differences reflecting slowed reaction time in the schizophrenia group disappeared when lower order skills were controlled for. Differences between groups performance in errors were only evident on the most complex versions of each task with more errors made by the schizophrenia group. These results suggest that (1) both RT and error data are needed to provide a full picture of performance and (2) the relationship between lower order and EF is too complex to provide support for one or the other proposal.

Aspects of Attention Predict Real-World Task Performance in Alzheimer's Disease

More research is needed to examine the relationship between specific neuropsychological functions and observation-based daily activity tests in patients with Alzheimer's disease (AD). Fifty-six patients with AD were administered tests of attention and processing speed and an observation-based activities-of-daily-living (ADL) task. Complex short-term attention capacity best predicted real-world task performance, accounting for several domains of ADL functioning. These results suggest that complex attention requiring working-memory systems, but not simple attention or processing speed, account for moderate portions of variability in daily task performance. These results may aid in understanding the attentional processes required for performing daily activities and can be useful to health care professionals in treatment planning.

Trail Making Test: regression-based norms for the Portuguese population

The main goal of this study was to produce normative data for the Portuguese population on the Trail Making Test (TMT). The study included 1,038 community-dwelling individuals aged between 18 and 93 years, who had educational backgrounds ranging from 3 to 22 years. The results showed that sex, age, and education were significantly associated with TMT performance. These demographic characteristics accounted for 57% of the performance variance at part A and 50% at part B. The normative data are presented as regression-based algorithms to adjust direct and derived test scores for sex, age, and education. The adjusted scores' percentile distributions and their correspondence with scaled scores are also provided.