An Adaptable, Open-Access Test Battery to Study the Fractionation of Executive-Functions in Diverse Populations

Abstract

The umbrella-term ‘executive functions’ (EF) includes various domain-general, goal-directed cognitive abilities responsible for behavioral self-regulation. The influential unity and diversity model of EF posits the existence of three correlated yet separable executive domains: inhibition, shifting and updating. These domains may be influenced by factors such as socioeconomic status (SES) and culture, possibly due to the way EF tasks are devised and to biased choice of stimuli, focusing on first-world testees. Here, we propose a FREE (Free Research Executive Function Evaluation) test battery that includes two open-access tasks for each of the three abovementioned executive domains to allow latent variables to be obtained. The tasks were selected from those that have been shown to be representative of each domain, that are not copyrighted and do not require special hardware/software to be administered. These tasks were adapted for use in populations with varying SES/schooling levels by simplifying tasks/instructions and using easily recognized stimuli such as pictures. Items are answered verbally and tasks are self-paced to minimize interference from individual differences in psychomotor and perceptual speed, to better isolate executive from other cognitive abilities. We tested these tasks on 146 early adolescents (aged 9–15 years) of both sexes and varying SES, because this is the age group in which the executive domains of interest become distinguishable and in order to confirm that SES effects were minimized. Performance was determined by Rate Correct Scores (correct answers divided by total time taken to complete blocks/trial), which consider speed-accuracy trade-offs. Scores were sensitive to the expected improvement in performance with age and rarely/inconsistently affected by sex and SES, as expected, with no floor or ceiling effects, or skewed distribution, thus suggesting their adequacy for diverse populations in these respects. Using structural equation modeling, evidence based on internal structure was obtained by replicating the three correlated-factor solution proposed by the authors of the model. We conclude that the FREE test battery, which is open access and described in detail, holds promise as a tool for research that can be adapted for a wide range of populations, as well as altered and/or complemented in coming studies.

Feasibility of Remote Performance Assessment Using the Free Research Executive Evaluation Test Battery in Adolescents

“…The FREE battery contains six tests adapted for use in diverse samples in terms of SES and cultural context. The theoretical basis for the battery, the rationale for choice of tasks, description of tasks, answer sheets and scoring method are detailed in Zanini (2021). A brief description of tasks and scoring procedure for each domain can be found in Table 1 and Figure 1. Following prior studies (see Zanini, 2021), the Inhibition and Switching tasks included blocks used to control for vocal/ psychomotor speed and a corresponding block with the same requirements plus executive demands, while the Updating tasks contained no such control, as is the norm in this field.…”

“…memory) and speed of progressing through all stimuli, which is also done in the Updating task (see Zanini, 2021).…”

“…In this scenario, remote EF cognitive testing must ensure health and safety of testees and examiners and also allow administration of cognitive tests that are adaptable to different cultural and socioeconomic contexts so as to more reliably capture the cognitive constructs under investigation ( Fernández and Abe, 2018 ). Bearing this in mind, we investigated the adequacy of remote EF assessment mediated by examiners using a test battery designed to be adaptable to different contexts and populations (FREE: Free Research Executive Function Evaluation; Zanini, 2021 ).…”

“…Testees themselves regulate the speed at which they can do tasks and respond vocally while the examiner measures accuracy and time taken to complete blocks of trials instead of each individual trial. This is important because many studies have shown that limiting exposure and response times and requiring key presses for verbal answers can negatively influence measurements of EF in samples that include participants with different characteristics, such as various ages, and who are from diverse backgrounds (see Zanini, 2021 ). This test battery may therefore be administered remotely and be moderated by an online examiner, using screen sharing services that may be downloaded and used by examiners and testees free of charge without any special hardware, software downloads or plug-ins.…”

“…Description of the self-paced executive function tasks per domain and their corresponding scores (based onZanini, 2021).Contains two blocks, each of which consists of 24 stimuli (color patches or words) displayed on a single screen. Participants name the ink color of patches (block 1) and words that are color names written in incongruous ink colors (block 2).…”