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

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

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

Normative Data for the D-KEFS Color-Word Interference and Trail Making Tests Adapted in Greek Adult Population 20-49 Years Old

BACKGROUND

This study was designed to adapt the Delis-Kaplan Executive System (D-KEFS) version of the Color-Word Interference (CWIT) and Trail Making Tests (TMTs) for the Greek adult population from 20 to 49 years old, since it is of research as well as clinical importance to detect executive functions' impairment in young adults with neurological or/and psychiatric conditions.

AIMS

Norms for the Greek adult population have been calculated to be available for neuropsychologists and health professionals who work in relevant settings.

METHODS

The study sample consisted of 101 healthy adults (41% male and 60% female) aged 20 to 49 years (M = 32.16, SD = 11.57) with education from 12 to 19 years of schooling (M = 14.51, SD = 0.89). A Pearson correlation test as well as a chi square test were conducted to examine potential associations between gender, age, education, and participants' performance. Afterwards, we calculated normative data using raw scores and transformed them into percentile scores. Finally, Greek norms were compared to the original raw scores, which were transformed into scaled scores by Delis et al. (2001).

RESULTS

The findings showed that age was the only variable which affected CWIT, whereas level of education as well as age were predictive factors for most TMT conditions, except for the visual scanning test (Condition 1). Gender did not affect both tests. Finally, D-KEFS norms for CWIT and TMT are available for the Greek adult population to help clinicians detect executive functions' deficits and therefore adjust tailored therapeutic strategies. Additionally, it is of great importance to use these tests for research purposes.

CONCLUSION

Given that executive functions are assumed as high-level skills, which are highly related to everyday functionality, adapted tests contribute not only to assess the progression of any existing neurological as well as psychiatric disorders, but they can also be used to evaluate patients' ability to live independently, as well as their access to work.

Six elements test vs D-KEFS: what does "Ecological Validity" tell us?

OBJECTIVE

Extensive research shows that tests of executive functioning (EF) predict instrumental activities of daily living (IADLs) but are nevertheless often criticized for having poor ecological validity. The Modified Six Elements Test (MSET) is a pencil-and-paper test that was developed to mimic the demands of daily life, with the assumption that this would result in a more ecologically valid test. Although the MSET has been extensively validated in its ability to capture cognitive deficits in various populations, support for its ability to predict functioning in daily life is mixed. This study aimed to examine the MSET's ability to predict IADLs assessed via three different modalities relative to traditional EF measures.

METHOD

Participants (93 adults aged 60 - 85) completed the MSET, traditional measures of EF (Delis-Kaplan Executive Function System; D-KEFS), and self-reported and performance-based IADLs in the lab. Participants then completed three weeks of IADL tasks at home, using the Daily Assessment of Independent Living and Executive Skills (DAILIES) protocol.

RESULTS

The MSET predicted only IADLs completed at home, while the D-KEFS predicted IADLs across all three modalities. Further, the D-KEFS predicted home-based IADLs beyond the MSET when pitted against each other, whereas the MSET did not contribute beyond the D-KEFS.

CONCLUSIONS

Traditional EF tests (D-KEFS) appear to be superior to the MSET in predicting IADLs in community-dwelling older adults. The present results argue against replacing traditional measures with the MSET when addressing functional independence of generally high-functioning and cognitive healthy older adult patients.

Test of Practical Judgment (TOP-J): Construct, Criterion, and Incremental Validity in a Community Sample of Older Adults

OBJECTIVE

The Test of Practical Judgment (TOP-J) is a stand-alone judgment measure that is considered to tap into aspects of executive functioning (EF) and inform clinical predictions of daily functioning in older adults. Past validation research is variable and has some limitations. The present study sought to examine the reliability and construct, criterion, and incremental validities of scores on TOP-J 9-item version (TOP-J/9).

METHOD

Participants were 95 community-dwelling older adults aged 60 to 85. Participants completed TOP-J/9, measures of EF and global cognition, and three different modalities of instrumental activities of daily living (IADLs) (self-report, performance-based tasks conducted in the laboratory, and performance-based tasks completed at home over 3 weeks).

RESULTS

TOP-J/9 scores showed adequate internal consistency (α = 0.73) after correcting for the low number of items. TOP-J/9 was correlated with global cognition and EF, although EF did not survive correction for lower-order processes. Finally, although TOP-J/9 scores were associated with home-based IADL tasks (but not with self-report and laboratory-based IADLs), providing some evidence of criterion validity, they did not incrementally contribute to home-based IADL performance beyond other cognitive measures. However, when two items pertaining to social/ethical judgment were removed, this modified version of TOP-J did relate to EF beyond lower-order processes and contributed uniquely to prediction of home-based IADLs beyond other measures.

CONCLUSION

Results suggest that TOP-J/9 taps into global cognitive status (but not necessarily EF) and predicts "real-world" functioning (but not above and beyond other cognitive measures). TOP-J psychometrics may be improved by removing two social/ethical items.

Delayed cortical thinning in children and adolescents with prenatal alcohol exposure

BACKGROUND

Prenatal alcohol exposure (PAE) is associated with abnormalities in cortical structure and maturation, including cortical thickness (CT), cortical volume, and surface area. This study provides a longitudinal context for the developmental trajectory and timing of abnormal cortical maturation in PAE.

METHODS

We studied 35 children with PAE and 30 nonexposed typically developing children (Comparisons), aged 8-17 at enrollment, who were recruited from the University of Minnesota FASD Program. Participants were matched on age and sex. They underwent a formal evaluation of growth and dysmorphic facial features associated with PAE and completed cognitive testing. MRI data were collected on a Siemens Prisma 3T scanner. Two sessions, each including MRI scans and cognitive testing, were spaced approximately 15 months apart on average. Change in CT and performance on tests of executive function (EF) were examined.

RESULTS

Significant age-by-group (PAE vs. Comparison) linear interaction effects in CT were observed in the parietal, temporal, occipital, and insular cortices suggesting altered developmental trajectories in the PAE vs. Comparison groups. Results suggest a pattern of delayed cortical thinning in PAE, with the Comparison group showing more rapid thinning at younger ages and those with PAE showing accelerated thinning at older ages. Overall, children in the PAE group showed reduced cortical thinning across time relative to the Comparison participants. Symmetrized percent change (SPC) in CT in several regions was significantly correlated with EF performance at 15-month follow-up for the Comparison group but not the group with PAE.

CONCLUSIONS

Regional differences were seen longitudinally in the trajectory and timing of CT change in children with PAE, suggesting delayed cortical maturation and an atypical pattern of development compared with typically developing individuals. In addition, exploratory correlation analyses of SPC and EF performance suggest the presence of atypical brain-behavior relationships in PAE. The findings highlight the potential role of altered developmental timing of cortical maturation in contributing to long-term functional impairment in PAE.

Long-term follow-up of a randomized controlled trial of choline for neurodevelopment in fetal alcohol spectrum disorder: corpus callosum white matter microstructure and neurocognitive outcomes

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is a lifelong condition. Early interventions targeting core neurocognitive deficits have the potential to confer long-term neurodevelopmental benefits. Time-targeted choline supplementation is one such intervention that has been shown to provide neurodevelopmental benefits that emerge with age during childhood. We present a long-term follow-up study evaluating the neurodevelopmental effects of early choline supplementation in children with FASD approximately 7 years on average after an initial efficacy trial.

METHODS

The initial study was a randomized, double-blind, placebo-controlled trial of choline vs. placebo in 2.5 to 5 year olds with FASD. Participants in this long-term follow-up study include 18 children (9 placebo; 9 choline) seen 7 years on average following initial trial completion. The mean age at follow-up was 11.0 years old. Diagnoses were 28% fetal alcohol syndrome (FAS), 28% partial FAS, and 44% alcohol-related neurodevelopmental disorder. The follow-up included measures of executive functioning and an MRI scan.

RESULTS

Children who received choline had better performance on several tasks of lower-order executive function (e.g., processing speed) and showed higher white matter microstructure organization (i.e., greater axon coherence) in the splenium of the corpus callosum compared to the placebo group.

CONCLUSIONS

These preliminary findings, although exploratory at this stage, highlight potential long-term benefits of choline as a neurodevelopmental intervention for FASD and suggest that choline may affect white matter development, representing a potential target of choline in this population.

TRIAL REGISTRATION

Prior to enrollment, this trial was registered with clinicaltrials.gov ( NCT01149538 ) on June 23, 2010.

Ecological validity reconsidered: the Night Out Task versus the D-KEFS

INTRODUCTION

Although executive functioning (EF) correlates with execution of instrumental activities of daily living (IADLs), tests of EF have been criticized for having poor ecological validity. Attempts have been made to develop new tests that approximate naturalistic daily tasks. However, the incremental utility of such tests has not been convincingly demonstrated. The Night Out Task (NOT) is a novel measure designed to increase ecological validity. This study examined whether the NOT correlates with traditional lab- and home-based measures of EF and IADLs, and whether it outperforms traditional measures of EF in predicting IADLs.

METHOD

Participants (50 adults aged 60 to 95) completed (1) the Delis Kaplan Executive Function System (D-KEFS) and IADLs in the laboratory, and (2) ecological momentary assessment of EF and daily IADL tasks at home across three weeks (using the Daily Assessment of Independent Living and Executive Skills protocol; DAILIES).

RESULTS

The NOT correlated with a lab-based measure of EF beyond covariates, and lab-based IADLs beyond covariates and beyond the D-KEFS. However, it was unrelated to at-home variables beyond covariates. In contrast, the D-KEFS was a significant predictor of at-home IADLs, and this association was mediated by at-home EF performance.

CONCLUSION

This study provides a preliminary validation of the NOT as a correlate of office-based performances in a primarily college educated white sample. Despite its high face validity, the NOT does not appear to sufficiently tap EF processes needed for home-based IADLs as measured by the DAILIES, although small sample size limits the interpretability of this negative finding.

Reappraising cognitive reappraisal: The taxing impact of emotion regulation on executive functioning in older adults

OBJECTIVE

Cognitive reappraisal (CR) and expressive suppression (ES) are two common emotion regulation strategies that share similar cognitive and neural underpinnings. Prior research has consistently shown that recent engagement in ES (both self-reported and experimentally manipulated) is associated with subsequent temporary decrements in executive functioning (EF). Thus far, only one study has examined the association between CR and EF, with null results. However, that study was limited by examining only zero-order correlations and by assessing only the speed, not accuracy, of EF performance. The present study examined multivariate relationships among recent CR, recent ES, and EF (both speed and accuracy), as well as the potential impacts of more chronic engagements in, and trait-level preferences between, the two emotion regulation strategies.

METHOD

Participants were 201 community-dwelling older adults aged 60 to 93 who had participated in three separate studies examining the relationship between self-reported emotion regulation and EF.

RESULTS

Recent CR was associated with EF performance accuracy above and beyond chronic CR. Both recent CR and ES contributed to EF performance accuracy uniquely beyond each other and beyond chronic and preferred emotion regulation.

CONCLUSIONS

Both recent ES and CR appear to have a deleterious impact on EF performance accuracy, potentially due to utilization of similar resources; both should be accounted for when assessing emotion regulation and its impacts on EF.