Absence of a bilingual cognitive flexibility advantage: A replication study in preschoolers

Some studies have found a bilingual advantage in children’s executive function and some failed to find a bilingual advantage. For example, the results of a previous study by Bialystok & Martin (2004) indicated that Chinese-English bilingual preschool children outperformed English monolingual children in solving the dimensional change card sort (DCCS). The goal of our study was to replicate this study using the same dimensional change card sort task. We also tested our participants on vocabulary and digit span. Our participants were 40 English monolingual and 40 Mandarin-English bilingual children and were within the same age range as the children in Bialystok & Martin’s (2004) study. Our results showed no difference between bilinguals and monolinguals. Both groups of children in the present study performed better than those in Bialystok and Martin (2004), but the bigger difference was between the two groups of monolinguals. These results suggest that it could be important to attend to monolingual children’s performance, in addition to bilinguals’, when testing for a bilingual advantage. Our replication study is important because it helps with clarifying the validity of studies finding a bilingual advantage and to help future researchers know whether to build on their findings or not.

U-Shape by Quadratic Equation: A Best-fit for Modelling Hemodynamic Changes in the DCCS Task

General Linear Modelling (GLM) has been widely employed to estimate the hemodynamic changes evoked by cognitive processing, which are more likely to be nonlinear than linear. First, this study re-analyzed the fNIRS data (N = 38, Mage = 5.0 years, SD = 0.69 years, 17 girls) collected in the Mixed-Order Design Dimensional Change Card Sort (DCCS) task. The results indicated that the quadratic equation was better than GLM to model HbO changes in this task. Second, analysis of a new set of data indicated that the Habit-DisHabit design of DCCS was more effective in identifying the neural correlates of cognitive shifting than the Mixed-Order Design. Third, this study found that the Non-users were more attentive and engaged than the Heavy-users, with a slower but more steady increase of brain activation in BA8 and BA9.

Peripheral Insulin Resistance Is Unrelated to Cognition in Highly Educated, Cognitively Normal Adults

Objectives Peripheral insulin resistance (IR) and impaired glucose metabolism increase the risk for cognitive decline. However, data looking at peripheral IR's relationship with cognition in cognitively normal adults is limited. This study aimed to assess the relationship between peripheral IR and tests of executive function, attention, and processing speed in cognitively normal older adults using a novel IR measure. Methods Baseline data from 81 cognitively normal older adults participating in a nutrition intervention study (Nutrition Interventions for Cognitive Enhancement study; NICE study) were analyzed. Fasting blood draws were attained, and peripheral IR was measured using Quest Diagnostics’ Cardio IQ Insulin Resistance Panel (Test Code: 36,509). The NIH Toolbox Cognition Battery was conducted by a trained psychometrician. Executive function was measured by the Flanker Inhibitory Control and Dimensional Change Card Sort tests. The Flanker test also measures attention. Processing Speed was measured by the Pattern Comparison Processing Speed test. We constructed ordinary least squares regression models to assess IR's relationships with the individual cognitive tests, including age, education, and gender as covariates. Statistical analyses were performed using R (v. 3.6.2; R Foundation, Vienna, Austria). Statistical significance was set at p < 0.05. Results Participants were 83% female and had a mean age of 72 ± 4.9 years. The mean IR score was 29.9 ± 29.83. There was no statistically significant relationships with IR and any of the cognitive tests: Flanker Inhibitory Control (β = -0.03, P = 0.12), Dimensional Change Card Sort (β = -0.03, P = 0.16), Pattern Comparison Processing Speed (β = -0.10, P = 0.15). Conclusions There were no statistically significant relationships between IR scores and performance on the different cognitive tests. Although the tests were not significantly correlated with IR scores, directionality of the relationships indicated trend for higher IR being related to poorer scores. Consequently, maintaining insulin sensitivity with healthy lifestyle choices may be important for healthy brain aging. Future analyses with a larger sample size will be more informative for understanding the relationship between IR and various cognitive tests at baseline and over time. Funding Sources National Institutes on Aging.

Tablet Use Affects Preschoolers’ Executive Function: fNIRS Evidence from the Dimensional Change Card Sort Task

This study aims to examine the impact of heavy use of tablets on preschoolers’ executive function during the Dimensional Change Card Sort (DCCS) task using the functional near-infrared spectroscopy (fNIRS). Altogether, 38 Chinese preschoolers (Mage = 5.0 years, SD = 0.69 years, 17 girls) completed the tasks before the COVID-19 lockdown. Eight children never used tablets, while 16 children were diagnosed as the ‘heavy-user’. The results indicated that: (1) the ‘non-user’ outperformed the ‘heavy-user’ with a significantly higher correct rate in the DCCS task; (2) the two groups differed significantly in the activation of the prefrontal cortex (BA 9): the ‘non-user’ pattern is normal and healthy, whereas the ‘heavy-user’ pattern is not normal and needs further exploration.

Processing of Code-Switched Sentences in Noise by Bilingual Children

Purpose The purpose of the current study was to examine the effects of code-switching on bilingual children's online processing and offline comprehension of sentences in the presence of noise. In addition, the study examined individual differences in language ability and cognitive control skills as moderators of children's ability to process code-switched sentences in noise. Method The participants were 50 Spanish–English bilingual children, ages 7;0–11;8 (years;months). Children completed an auditory moving window task to examine whether they processed sentences with code-switching more slowly and less accurately than single-language sentences in the presence of noise. They completed the Dimensional Change Card Sort task to index cognitive control and standardized language measures in English and Spanish to index relative language dominance and overall language ability. Results Children were significantly less accurate in answering offline comprehension questions about code-switched sentences presented in noise compared to single-language sentences, especially for their dominant language. They also tended to exhibit slower processing speed, but costs did not reach significance. Language ability had an overall effect on offline comprehension but did not moderate the effects of code-switching. Cognitive control moderated the extent to which offline comprehension costs were affected by language dominance. Conclusions The findings of the current study suggest that code-switching, especially in the presence of background noise, may place additional demands on children's ability to comprehend sentences. However, it may be the processing of the nondominant language, rather than code-switching per se, that is especially difficult in the presence of noise.

Tablet Use Affects Preschoolers’ Executive Function: fNIRS Evidence from the Dimensional Change Card Sort Task

This study aims to examine the impact of tablet use on preschoolers’ executive function during the Dimensional Change Card Sort Task (DCCS) task using the functional near-infrared spectroscopy (fNIRS). Altogether 38 Chinese preschoolers (Mage = 5.0 years, SD = 0.69 years, 17 girls) completed the tasks before the COVID-19 lockdown. Eight children never used tablets, while 16 children were diagnosed as the ‘heavy-user'. The results indicated that: (1) the 'Non-user' outperformed the 'Heavy-user' with a significantly higher correct rate in the DCCS task; (2) the two groups differed significantly in the activation of the prefrontal cortex (BA 9): the 'Non-user' pattern is normal and healthy, whereas the 'Heavy-user' pattern is not normal and needs further exploration.

Improving Dimensional Change Card Sort Performance of Preschoolers With Developmental Language Disorder: Effects of Two Task Variations

Purpose This research note addresses whether task administration variations can improve Dimensional Change Card Sort (DCCS) performance in preschoolers with developmental language disorder (DLD). Method Participants included preschoolers with DLD who failed the standard DCCS, which is characterized by inability to switch from one card sorting rule to a new rule. After an approximately 2.5-month delay, participants were retested on the DCCS in one of three conditions: repeating standard administration, participants labeling relevant card dimensions, or briefly removing target cards before the switch. Results Children in both the labeling and target removal conditions scored significantly higher on the second administration relative to the first. However, comparing across conditions, participants in the target removal condition scored higher on the second DCCS compared to participants in the standard and labeling conditions, which did not differ from each other. Conclusions DCCS performance of preschoolers with DLD can be improved by changing task administration. The most effective change is increasing the salience of the switch to the new sorting rule, as opposed to directing children's attention via their own labeling behavior.

A Functional Near-Infrared Spectroscopy Examination of the Neural Correlates of Cognitive Shifting in Dimensional Change Card Sort Task

This study aims to examine the neural correlates of cognitive shifting during the Dimensional Change Card Sort Task (DCCS) task with functional near-infrared spectroscopy. Altogether 49 children completed the DCCS tasks, and 25 children (Mage = 68.66, SD = 5.3) passing all items were classified into the Switch group. Twenty children (Mage = 62.05, SD = 8.13) committing more than one perseverative errors were grouped into the Perseverate group. The Switch group had Brodmann Area (BA) 9 and 10 activated in the pre-switch period and BA 6, 9, 10, 40, and 44 in the post-switch period. In contrast, the Perseverate group had BA 9 and 10 activated in the pre-switch period and BA 8, 9, 10 in the post-switch period. The general linear model results afford strong support to the “V-shape curve” hypothesis by identifying a significant decrease–increase cycle in BA 9 and 44, the neural correlations of cognitive shifting.

Children Only 3 Years Old Can Succeed at Conditional “If, Then” Reasoning, Much Earlier Than Anyone Had Thought Possible

That conditional, if-then reasoning does not emerge until 4–5 years has long been accepted. Here we show that children barely 3 years old can do conditional reasoning. All that was needed was a superficial change to the stimuli: When color was a property of the shapes (line drawings of a star and truck) rather than of the background (as in all past conditional discrimination [CD] testing), 3-year-olds could succeed. Three-year-olds do not seem to use color to inform them which shape is correct unless color is a property of the shapes themselves. While CD requires integrating color and shape information, the dimensional change card sort (DCCS) task requires keeping those dimension cognitively separate – inhibiting attention to one (e.g., shape) when sorting by the other (e.g., color). For DCCS, a superficial change to the stimuli that is the inverse of what helps on CD enables 3-year-olds to succeed when normally they do not until ∼4⁤12 years. As we and others have previously shown, 3-year-olds can succeed at DCCS when color is a property of the background (e.g., a white truck on a red background), instead of a property of the stimulus (e.g., a red truck on a white background, as in standard DCCS). Our findings on CD and DCCS suggest that scaffolding preschoolers’ emerging conceptual skills by changing the way stimuli look (perceptual bootstrapping) enables 3-year-olds to demonstrate reasoning abilities long thought beyond their grasp. Evidently, children of 3 years have difficulty mentally separating dimensions (e.g., color and shape) of the same object and difficulty mentally integrating dimensions not part of the same object. Our present CD findings plus our earlier DCCS findings provide strong evidence against prominent cognitive complexity, conditional reasoning, and graded memory theories for why 3-year-olds fail these two tasks. The ways we have traditionally queried children may have obscured the budding reasoning competencies present at 3 years of age.