Sensitivity, specificity and predictive value of the BADS to anterior executive dysfunction

Branching Condition of the Color-Word Interference Test Enhances Prediction of Meta-Tasking in Community-Dwelling Older Adults

OBJECTIVES

Meta-tasking (MT) is an aspect of executive functioning (EF) that involves the ability to branch (i.e., to apply "if-then" rules) and to effectively interleave sub-goals of one task with sub-goals of another task. As such, MT is crucial for successful planning, coordination, and execution of multiple complex tasks in daily life. Traditional tests of EF fail to adequately measure MT. This study examined whether Condition 4 of the Color-Word Interference Test (CWIT-4; the inhibition/switching condition that requires branching) predicted MT beyond Condition 3 (CWIT-3; inhibition-only condition) and beyond other subtests from the Delis-Kaplan Executive Function System (D-KEFS) that have a switching condition.

METHOD

Ninety-eight non-Hispanic white community-dwelling older adults completed the first four subtests of the D-KEFS and an ecologically valid measure of MT.

RESULTS

Time to completion and total errors on CWIT-4 accounted for variance in MT above and beyond CWIT-3 and beyond the switching conditions of other D-KEFS subtests. Results remained virtually unchanged when controlling for demographics and general cognitive status.

CONCLUSIONS

Among older adults, CWIT-4 is more strongly associated with MT than other D-KFES tasks. Future research should examine whether CWIT-4 relates to lapses in instrumental activities of daily living among older adults above and beyond other EF tests.

Incorporation of a working memory strategy in GMT to facilitate serial-order behaviour in brain-injured patients

Goal Management Training (GMT) is an effective method for improving disorganised behaviour in multistep real-life tasks after brain damage. In the present study we incorporated Working Memory Training (WMT) in GMT to explore their combined efficacy in facilitating the serial-order maintenance of the steps that had to be learned. GMT+WMT was compared to a control WMT designed for other purposes. For this purpose 18 brain-injured patients (aged 20-54), who were at least 4 months post-onset, were randomly assigned to either the GMT+WMT or the WMT treatment. Inclusion was based on a baseline score of less than six correct steps on each of two multistep everyday tasks. Alternative versions of these tasks were used as primary outcome tasks. Pre-treatment and post-treatment comparisons of scores on these primary tasks and on several secondary neuropsychological measures were collected. The results show that post-treatment the GMT+WMT group performed significantly better than the WMT group on the primary outcome measures and on several ecologically valid executive tests that demanded a step-by-step maintenance of multiple actions. Time effects were found for both groups on the secondary measures. Other measures showed no significant differences. We conclude that our results support the efficacy of the combined GMT+WMT in facilitating performance in everyday multistep tasks.

Assessing Cognitive Estimation and Its Effects on Community Integration in People with Acquired Brain Injury Undergoing Rehabilitation

The purpose of the present study was to examine the convergent and divergent validity of the Biber Cognitive Estimation Test (BCET) in individuals with ABI undergoing postacute rehabilitation and to assess the measure's ability to account for unique variance in community integration following rehabilitation. Participants with ABI referred for postacute rehabilitation (N = 201) were assessed on the BCET and a number of other neuropsychological tests that have been demonstrated to rely on aspects of executive processing (Trail-Making Test, Modified Six Elements Test, and verbal fluency measures) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Internal consistency of the total BCET was good; however, interpretable solutions for existing subscales were not discerned. The BCET total score demonstrated positive associations with tests of executive functioning; however, it was also significantly associated with more general aspects of neuropsychological functioning suggesting that it does not solely assess executive processes in ABI patients undergoing rehabilitation. Hierarchical multiple regression suggested that the BCET accounted for significant additional variance in community integration after severity of disability, executive functioning, and more general aspects of neuropsychological status were statistically controlled. While the subscale structure of the BCET may be somewhat inconsistent, the total scale score accounts for some unique variance in pragmatic rehabilitation outcome and may be a useful tool in postacute rehabilitation assessment protocols.

Script Generation and Executive Dysfunction in Patients with Anterior and Posterior Brain Lesions

Introduction: Studies on script processing have shown inconsistent relations between deficits in script action generation and frontal lobe pathology. Therefore, we investigated which difficulties in script action generation are linked to anterior lesions. Moreover, we explored whether verbal script generation can be predicted by specific executive processes.

Methods: Fifty-two patients with acquired brain injury (mean age: 44.23 years, 30 male/22 female) were included, of whom 30 had anterior and 22 had posterior lesions. Several indices of the Everyday Description Task were investigated: relevant central actions (RCAs); relevant trivial actions (RTAs); relevant and irrelevant intrusions (RI & IRI); sequencing (SEs) and perseverative (PEs) errors. Additionally, fivez-composite scores representing planning, response generation, working memory, inhibition and shifting were calculated. Correlations and multiple linear regression analyses were computed.

Results: Anteriorly lesioned patients produced significantly less RCAs and more PEs and SEs compared to posteriorly damaged patients. No differences were found with RTAs, RI and IRI. RCAs were predicted by planning, response generation and working memory, RI by response generation and working memory, IRI by inhibition, PEs and SEs by response generation and shifting. None of these executive processes predicted RTAs.

Conclusions: Difficulties in RCAs, PEs and SEs are sensitive indicators of anterior brain damage and script generation demands various executive abilities.

Reliability of an Adapted Version of the Modified Six Elements Test as a Measure of Executive Function

The Modified Six Elements Test (MSET) is used to examine executive deficits-more specifically, planning deficits. This study investigates the reliability of an adapted version of the MSET and proposes a novel scoring method. Two parallel versions of the adapted MSET were administered in 60 healthy participants in a counterbalanced order. Test-retest and parallel-form reliability were examined using intraclass correlation coefficients, Bland-Altman analyses, standard errors of measurement, and smallest real differences, representing clinically relevant changes over time. Moreover, the ecological validity of the adapted MSET was evaluated using the Executive Function Index, a self-rating questionnaire measuring everyday executive performance. No systematic differences between the test occasions were present, and the adapted MSET including the proposed scoring method was capable of detecting real clinical changes. Intraclass correlations for the test-retest and parallel-form reliability were modest, and the variability between the test scores was high. The nonsignificant correlations with the Executive Function Index did not confirm the previously established ecological validity of the MSET. We show that both parallel versions of the test are clinically equivalent and can be used to measure executive function over the course of time without task-specific learning effects.