Confirmatory Factor Analysis of Neurocognitive Measures in Healthy Young Adults: The Relation of Executive Functions with Other Neurocognitive Functions

BRIEF-A: Factor structure and measurement invariance across self-report and informant forms

OBJECTIVE

This study analyzes the psychometric properties of the two forms (self-report and informant) of the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) in a sample of healthy Portuguese adults.

METHOD

The participants were 608 adults, 304 of whom answered the self-report form (ages 18-59; 137 male and 167 female) and 304 who answered the informant form (ages 18-70; 110 male and 194 female).

RESULTS

The internal consistency for the indexes and the Global Executive Composite was very good (≥.90), whereas for the scales they were either acceptable (between .70 and .80) or good (≥.80), except for the Inhibit scale in both forms. Confirmatory factor analysis was used to test seven competing factor models for each of the forms. The original two-factor model (Behavioral Regulation and Metacognition Indexes) showed a slightly better model fit than the three-factor model (Behavioral Regulation, Emotional Regulation, and Metacognition Indexes) in both forms. The multiple-group analysis of the two-correlated-factor model across forms was supported (configural, metric, and partial scalar invariance).

CONCLUSIONS

Overall, the BRIEF-A showed adequate psychometric properties, suggesting that it is a useful instrument to assess everyday executive functioning in healthy Portuguese adults.

Neuropsychological differential diagnosis of Alzheimer's disease and vascular dementia: a systematic review with meta-regressions

Introduction

Diagnostic classification systems and guidelines posit distinguishing patterns of impairment in Alzheimer's (AD) and vascular dementia (VaD). In our study, we aim to identify which diagnostic instruments distinguish them.

Methods

We searched PubMed and PsychInfo for empirical studies published until December 2020, which investigated differences in cognitive, behavioral, psychiatric, and functional measures in patients older than 64 years and reported information on VaD subtype, age, education, dementia severity, and proportion of women. We systematically reviewed these studies and conducted Bayesian hierarchical meta-regressions to quantify the evidence for differences using the Bayes factor (BF). The risk of bias was assessed using the Newcastle-Ottawa-Scale and funnel plots.

Results

We identified 122 studies with 17,850 AD and 5,247 VaD patients. Methodological limitations of the included studies are low comparability of patient groups and an untransparent patient selection process. In the digit span backward task, AD patients were nine times more probable (BF = 9.38) to outperform VaD patients (β g = 0.33, 95% ETI = 0.12, 0.52). In the phonemic fluency task, AD patients outperformed subcortical VaD (sVaD) patients (β g = 0.51, 95% ETI = 0.22, 0.77, BF = 42.36). VaD patients, in contrast, outperformed AD patients in verbal (β g = -0.61, 95% ETI = -0.97, -0.26, BF = 22.71) and visual (β g = -0.85, 95% ETI = -1.29, -0.32, BF = 13.67) delayed recall. We found the greatest difference in verbal memory, showing that sVaD patients outperform AD patients (β g = -0.64, 95% ETI = -0.88, -0.36, BF = 72.97). Finally, AD patients performed worse than sVaD patients in recognition memory tasks (β g = -0.76, 95% ETI = -1.26, -0.26, BF = 11.50).

Conclusion

Our findings show inferior performance of AD in episodic memory and superior performance in working memory. We found little support for other differences proposed by diagnostic systems and diagnostic guidelines. The utility of cognitive, behavioral, psychiatric, and functional measures in differential diagnosis is limited and should be complemented by other information. Finally, we identify research areas and avenues, which could significantly improve the diagnostic value of cognitive measures.

20 years on: Confirmation of P. Anderson's (2002) paediatric model of executive functioning in a healthy adult sample

Executive Functioning (EF) is a construct that encompasses multiple interrelated higher order skills, however, conceptualising this nebulous construct remains challenging. This study aimed to confirm the validity of Anderson's (2002) paediatric model of EF in a healthy adult sample using congeneric modelling. Measures of EF were selected based on utility with adult populations giving rise to minor methodological differences from the original paper. Separate congeneric models were constructed using each of Anderson's constructs in order to isolate the sub-skills represented by each (Attentional Control-AC, Cognitive Flexibility-CF, Information Processing-IP, Goal Setting-GS), with a minimum of three tests per subskill. One hundred and thirty-three adults (42 males and 91 females) aged between 18 and 50 (M = 29.68, SD = 7.46) completed a cognitive test battery comprising 20 EF tests. AC revealed a good fitting model χ²(2) = 1.61, p = .447, RMSEA = 0.000, CFI = 1.000, after removing the non-significant indicator Map Search (p = .349), and BS-Bk as BS-Bk was required to covary with both BS-Fwd (M.I = 7.160, Par Change = .706), and TMT-A (M.I = 5.759, Par Change = -2.417). CF revealed a good fitting model χ²(8) = 2.90, p = .940, RMSEA = 0.000, CFI = 1.000 after covarying TSC-E and Stroop (M.I = 9.696, Par Change = .085). IP revealed a good fitting model χ²(4) = 1.15, p = .886, RMSEA = 0.000, CFI = 1.000 after covarying Animals total and FAS total (M.I. = 4.619, Par Change = 9.068). Lastly, GS indicated a good fitting model χ²(8) = 7.22, p = .513, RMSEA = 0.000, CFI = 1.000 after covarying TOH total time and PA (M.I = 4.25, Par Change = -77.868). Therefore, all four constructs were reliable and valid, and the utility of a parsimonious EF battery is suggested. Investigation of the inter-relationships between the constructs using regression techniques, de-emphasises the role of Attentional Control and argue instead for capacity bound skills.

Neurocognition and its association with adverse childhood experiences and familial risk of mental illness

Environmental factors such as adverse childhood experiences (ACEs) may affect neurocognition, an endophenotype for several mental illnesses. This study examines the effect of ACEs on neurocognitive performance in first-degree relatives (FDRs) of patients with severe mental illness to determine whether familial risk has a moderating effect on the relationship between ACEs and neurocognition. Unaffected FDRs from multiplex families with severe mental illnesses (schizophrenia, bipolar disorder, obsessive-compulsive disorder, or alcohol use disorder) (n = 324) and healthy controls (with no familial risk) (n = 188) underwent neurocognitive tests for processing speed, new learning, working memory and Theory of Mind. ACEs were measured using the WHO ACE-International Questionnaire (ACE-IQ). Regression models were done to predict each neurocognitive domain by the effect of familial risk, ACE-IQ Score and their interaction (familial risk*ACE-IQ score). The main effect of familial risk predicted poor performance in all domains of neurocognition (p < 0.01), and the interaction had a negative association with global neurocognition (β = -0.093, p = 0.009), processing speed (β = -0.109, p = 0.003) and working memory (β = -0.092, p = 0.01). Among the ACEs sub-domains, only maltreatment (specifically the main effect of physical neglect and the interaction effect of sexual abuse with familial risk) predicted poorer neurocognition. In FDRs of schizophrenia and bipolar disorder, only the main effects of familial risk were significantly associated with poorer neurocognition. We conclude that there is a relationship between ACEs (especially maltreatment) and neurocognitive functioning, which is moderated by the familial risk of mental illnesses. Genetic/familial vulnerability may have a stronger association with neurocognition in schizophrenia and bipolar disorder.

The Structure of Processing Speed in Children and its Impact on Reading

The present study had two aims. First, we set out to evaluate the structure of processing speed in children by comparing five alternative models: two conceptual models (a unitary model, a complexity model) and three methodological models (a stimulus material model, an output response model, and a timing modality model). Second, we then used the resulting models to predict multiple types of reading, a highly important developmental outcome, using other well-known predictors as covariates. Participants were 844 children enrolled in third through fifth grade in urban public elementary schools who received 16 measures of processing speed that varied in the above dimensions. A two-factor complexity model that differentiated between simple and complex processing speed was the preferred model and fit the data well. Both types of PS predicted reading fluency, and complex (but not simple) PS predicted single word reading and comprehension. Results offer insight to the structure of processing speed, its relation to closely related concepts (such as executive function), and provide nuance to the understanding of the way processing speed influences reading.

The role of impulsivity in neurorehabilitation: A prospective cohort study of a potential cognitive biomarker for fall risk?

BACKGROUND

Executive dysregulation and impulsivity can both predispose individuals to risk-prone actions. Although the risk of falls is well established in people with poor executive function, its association to impulsivity is less clear.

PURPOSE

To describe and assess the prognostic capabilities of the relationship between impulsivity, executive function, functional capability, and falls in the in-patient neurorehabilitation population.

MATERIALS AND METHODS

A prospective cohort study in a 26-bed neurorehabilitation unit in London, recruiting 121 patients, of whom 94 were deemed eligible for inclusion. Cognitive-behavioural assessment was undertaken using the short (16-item) version of the Urgency-Premeditation-Perseverance-Sensation Seeking-Positive Urgency (UPPS) impulsive behaviour scale, and the Trail Making Test (TMT). Patients also underwent a functional assessment at admission and discharge using the UK Functional Independence and Assessment Measure tool (FIM + FAM). The main outcome of interest was falling during an in-patient episode, which are routinely recorded in a computerized registry of adverse incidents.

RESULTS

Measurements of impulsivity (based on the UPPS-Short form) and executive function (based on the Trail Making Test) were not found to be significantly associated with functional improvement, or risk of falling. Predictive modelling experiments demonstrated that neither of the aforementioned results were capable of identifying individuals at risk of falling more accurately than an informed guess.

CONCLUSION

Where impulsivity is present, measurement using structured tools such as the UPPS may be informative to guide individualized rehabilitation programmes; however, its usefulness as the basis of risk prediction models for falls is less likely given the results of this study.

The Factorial Structure of the Tower Test From the Delis-Kaplan Executive Function System: A Confirmatory Factor Analysis Study

The Tower of London (TOL) is a well-known, widely used task that captures executive function abilities. We examined the factorial structure and discriminant validity of three measures extracted from the Delis-Kaplan Executive Function System (D-KEFS) version of the TOL, namely the D-KEFS Tower Test, in 270 individuals from a publicly available release of the Enhanced Nathan Kline Institute-Rockland sample. Confirmatory factor analyses revealed a multidimensional three-factor solution of the measures extracted from the D-KEFS Tower Test; first-move-time, excess moves, and rule violations. This model was better than the unidimensional model, the two-factor model, the bifactor model and the model that included the total achievement scores. These results support the discriminant validity of the three latent factors, over their distinct relations to the total achievement score. The best fitting model was gender-invariant and age-variant. Overall, the multidimensionality of the measures extracted from the D-KEFS Tower Test reflects the need to use multiple metrics from this version of TOL to capture executive functions instead of a single score.

Response initiation and inhibition and the relationship with fluid intelligence across the adult lifespan

Background

Cognitive processes associated with frontal lobe functioning are often termed “executive functions.” Two such processes are initiation and inhibition or the starting and stopping of responses. It has recently been claimed dysfunction of executive abilities can be explained by a single measure of fluid intelligence. Here, we test this claim, specifically for the executive abilities of response initiation and inhibition, across the healthy lifespan.

Method

In a cohort of 336 healthy adults (18–89 years), initiation and inhibition were assessed with the Hayling test, Stroop test, and phonemic and semantic verbal fluency. All participants also completed a measure of fluid intelligence. The relationship between fluid intelligence and executive measures was explored across the lifespan using a continuous approach. Mediation models were computed to assess whether age-related decline across the four initiation/inhibition tasks could be fully explained by a single measure of fluid intelligence.

Results

Age was negatively correlated with response initiation/inhibition and fluid intelligence. The mediation analyses identified only partial mediation of fluid intelligence for age and Hayling performance. By contrast, fluid intelligence did not mediate performance on the Stroop test or phonemic and semantic verbal fluency.

Conclusions

Response initiation/inhibition are not able to be explained by fluid intelligence. The results support a multifactorial theory of executive functions and provide evidence for the inclusion of multiple specific executive measures in a thorough neuropsychological assessment of age-related cognitive decline.