Developmental differences in the structure of executive function in middle childhood and adolescence

Although it has been argued that the structure of executive function (EF) may change developmentally, there is little empirical research to examine this view in middle childhood and adolescence. The main objective of this study was to examine developmental changes in the component structure of EF in a large sample (N = 457) of 7–15 year olds. Participants completed batteries of tasks that measured three components of EF: updating working memory (UWM), inhibition, and shifting. Confirmatory factor analysis (CFA) was used to test five alternative models in 7–9 year olds, 10–12 year olds, and 13–15 year olds. The results of CFA showed that a single-factor EF model best explained EF performance in 7–9-year-old and 10–12-year-old groups, namely unitary EF, though this single factor explained different amounts of variance at these two ages. In contrast, a three-factor model that included UWM, inhibition, and shifting best accounted for the data from 13–15 year olds, namely diverse EF. In sum, during middle childhood, putative measures of UWM, inhibition, and shifting may rely on similar underlying cognitive processes. Importantly, our findings suggest that developmental dissociations in these three EF components do not emerge until children transition into adolescence. These findings provided empirical evidence for the development of EF structure which progressed from unity to diversity during middle childhood and adolescence

Speed Effect Analysis Using the CFA Framework

The paper outlines a method for investigating the speed effect due to a time limit in testing. It is assumed that the time limit enables latent processing speed to influence responses by causing omissions in the case of insufficient speed. Because of processing speed as additional latent source, the customary confirmatory factor model is enlarged by a second latent variable representing latent processing speed. For distinguishing this effect from other method effects, the factor loadings are fixed according to the cumulative normal distribution. With the second latent variable added, confirmatory factor analysis of reasoning data (N=518) including omissions because of a time limit yielded good model fit and discriminated the speed effect from other possible effects due to the item difficulty, the homogeneity of an item subset and the item positions. Because of the crucial role of the cumulative normal distribution for fixing the factor loadings a check of the normality assumption is also reported

Speed Effect Analysis Using the CFA Framework

The paper outlines a method for investigating the speed effect due to a time limit in testing. It is assumed that the time limit enables latent processing speed to influence responses by causing omissions in the case of insufficient speed. Because of processing speed as additional latent source, the customary confirmatory factor model is enlarged by a second latent variable representing latent processing speed. For distinguishing this effect from other method effects, the factor loadings are fixed according to the cumulative normal distribution. With the second latent variable added, confirmatory factor analysis of reasoning data (N=518) including omissions because of a time limit yielded good model fit and discriminated the speed effect from other possible effects due to the item difficulty, the homogeneity of an item subset and the item positions. Because of the crucial role of the cumulative normal distribution for fixing the factor loadings a check of the normality assumption is also reported

The position effect in tests with a time limit: the consideration of interruption and working speed

Abstract The position effect is a possible source of impairment of the structural validity of a test concerning model fit. In the case of tests with a time limit there is even a complication of the situation because of a decreasing number of participants completing the last few items of the test. Therefore, it is assumed that the appropriate representation of the position effect must additionally consider interruption due to the time limit and the effect of working speed. Interruption can be represented by the same latent variable as the position effect whereas the contribution of working speed requires another one. Confirmatory factor models including a representation of the position effect as a linear, quadratic or logarithmic increase were compared with models additionally considering interruption as a logistic decrease or simply as immediate interruption. Furthermore, there were models additionally considering working speed. In the sample of 305 participants the investigation of probability-based covariances made apparent that the modeling of interruption and also working speed substantially improved model fit. The best-fitting model was characterized by a linearly increasing representation of the position effect combined with a logistic decrease in the more difficult items and a contribution due to working speed

Strategy use moderates the relation between working memory capacity and fluid intelligence: A combined approach

This study investigated whether the strength of the link between working memory capacity (WMC) and fluid intelligence (Gf) differs as people use different strategies to solve Gf problems. A sample of 214 university students completed three complex span tasks measuring WMC and Raven's Advanced Progressive Matrices (APM) assessing Gf. Strategic behavior was measured by both the strategy questionnaire and the eye-tracking technique. Latent profile analysis yielded three groups of participants using the constructive matching, response elimination, and isolate-and-eliminate strategies, respectively. Participants adopting the constructive matching strategy spent proportionally more time on the matrix area but less time on the response bank, exhibited longer latency to first toggle and higher rate of toggling than those using the eliminative strategies, consistent with the results obtained from the questionnaire data. Furthermore, strategy use moderated the relationship between WMC and APM performance. The link between WMC and APM scores was significantly higher for participants using the eliminative strategies including response elimination (r = .63) and isolate-and-eliminate (r = .54) than that for those using constructive matching (r = .27). Our findings suggest that the extent to which WMC relates to performance on APM varies as a function of strategy use

How executive processes explain the overlap between working memory capacity and fluid intelligence: a test of process overlap theory

Working memory capacity (WMC) and fluid intelligence (Gf) are highly correlated, but what accounts for this relationship remains elusive. Process-overlap theory (POT) proposes that the positive manifold is mainly caused by the overlap of domain-general executive processes which are involved in a battery of mental tests. Thus, executive processes are proposed to explain the relationship between WMC and Gf. The current study aims to (1) achieve a relatively purified representation of the core executive processes including shifting and inhibition by a novel approach combining experimental manipulations and fixed-links modeling, and (2) to explore whether these executive processes account for the overlap between WMC and Gf. To these ends, we reanalyzed data of 215 university students who completed measures of WMC, Gf, and executive processes. Results showed that the model with a common factor, as well as shifting and inhibition factors, provided the best fit to the data of the executive function (EF) task. These components explained around 88% of the variance shared by WMC and Gf. However, it was the common EF factor, rather than inhibition and shifting, that played a major part in explaining the common variance. These results do not support POT as underlying the relationship between WMC and Gf

Shifting as an executive function separate from updating and inhibition in old age: Behavioral and genetic evidence

This study aimed to examine the organization of executive functions (EFs), specifically working memory updating, prepotent response inhibition, and mental-set shifting in old age, with a particular focus on determining whether the shifting function was behaviorally and genetically separated from the other functions. A total of 248 healthy older Chinese individuals participated, and multiple measures of executive functions were collected. Additionally, measures of fluid intelligence were included to explore the varying relationships between the three executive functions and this higher-order cognitive ability. Furthermore, genetic data were gathered and analyzed to investigate the associations between EFs and six candidate single-nucleotide polymorphisms (SNPs) mapped to dopaminergic, serotonergic, or glutamatergic genes. The results indicated that both the three-factor model and the two-factor model, which combined updating and inhibition, demonstrated a good fit. Furthermore, shifting was found to be behaviorally separated from the other two functions, and the correlation between shifting and fluid intelligence was smaller compared to the correlations between updating and inhibition with fluid intelligence. Moreover, the DRD2 SNPs showed significant associations with shifting, rather than with updating and inhibition. These findings provide evidence that shifting is distinct and separate from updating and inhibition, highlighting the diversity of EFs among older adults

Consensus to 99mTechnetium-Pyrophosphate Scintigraphy in the Diagnosis of Transthyretin-related Cardiac Amyloidosis

Transthyretin-related amyloid cardiomyopathy (ATTR-CM) is a disease caused by the depo-sition of insoluble amyloid fibers formed by the misfolding of transthyretin precursor protein in the intercellular space of cardiomyocytes. This lesion may lead to myocardial dysfunction, cogestive heart failure, and death.When diagnosed earlier, the patient can be treated with drugs as soon as possible to intervene in the progress of the disease, so as to effectively improve the patient's prognosis.99mtechnetium-pyrophosphate (99Tcm-PYP)single-photon emission computed tomography (SPECT) has been widely used in the imaging examination of cardiac amyloidosis (CA) in recent years. While achieving early non-invasive diagnosis, accurate pathological classification can be obtained through Perugini visual score analysis, semi-quantitative analysis of heart to contralateral lung (H/CL) ratio, and SPECT image analysis. This article presents the application, methods, and the precautions of 99Tcm-PYPSPECT in the diagnosis of ATTR-CM, aiming to provide clinical reference for the application of this technology