Best Graph Type to Compare Discrete Groups: Bar, Dot, and Tally

Different graph types might differ in group comparison due to differences in underlying graph schemas. Thus, this study examined whether graph schemas are based on perceptual features (i.e., each graph has a specific schema) or common invariant structures (i.e., graphs share several common schemas), and which graphic type (bar vs. dot vs. tally) is the best to compare discrete groups. Three experiments were conducted using the mixing-costs paradigm. Participants received graphs with quantities for three groups in randomized positions and were given the task of comparing two groups. The results suggested that graph schemas are based on a common invariant structure. Tally charts mixed either with bar graphs or with dot graphs showed mixing costs. Yet, bar and dot graphs showed no mixing costs when paired together. Tally charts were the more efficient format for group comparison compared to bar graphs. Moreover, processing time increased when the position difference of compared groups was increased.

Sociolinguistic Diversity Can Boost Cognitive Functions

This study investigates the link between sociolinguistic diversity and executive functions. 127 healthy adults from Malaysia were recruited to complete three cognitive tasks and the Contextual Linguistic Profile Questionnaire (CLiP-Q). A sociolinguistic diversity score was derived for each participant, with a higher score reflecting a greater exposure and use of diverse languages both at the individual and the societal level. The results demonstrated a sociolinguistic diversity advantage in cognitive functions. Higher sociolinguistic diversity scores were associated with lesser interference in the Flanker task and better accuracy in the 2-back task. Additionally, a significant interaction between sociolinguistic diversity and socioeconomic status was found for the set-shifting task, showing that sociolinguistic diversity could reduce mixing costs and improve set-shifting task accuracy for low socioeconomic status participants who are usually disadvantaged in cognitive control. Thus, it is important for research in the multilingualism field to take sociolinguistic diversity context into account.

Fronto-parietal homotopy in resting-state functional connectivity predicts task-switching performance

Homotopic functional connectivity reflects the degree of synchrony in spontaneous activity between homologous voxels in the two hemispheres. Previous studies have associated increased brain homotopy and decreased white matter integrity with performance decrements on different cognitive tasks across the life-span. Here, we correlated functional homotopy, both at the whole-brain level and specifically in fronto-parietal network nodes, with task-switching performance in young adults. Cue-to-target intervals (CTI: 300 vs. 1200 ms) were manipulated on a trial-by-trial basis to modulate cognitive demands and strategic control. We found that mixing costs, a measure of task-set maintenance and monitoring, were significantly correlated to homotopy in different nodes of the fronto-parietal network depending on CTI. In particular, mixing costs for short CTI trials were smaller with lower homotopy in the superior frontal gyrus, whereas mixing costs for long CTI trials were smaller with lower homotopy in the supramarginal gyrus. These results were specific to the fronto-parietal network, as similar voxel-wise analyses within a control language network did not yield significant correlations with behavior. These findings extend previous literature on the relationship between homotopy and cognitive performance to task-switching, and show a dissociable role of homotopy in different fronto-parietal nodes depending on task demands.

Bilinguals’ and monolinguals’ performance on a non-verbal cognitive control task: How bilingual language experience contributes to cognitive performance by reducing mixing and switching costs

Aims and objectives/purpose/research questions: The study investigated whether language experience predicts cognitive performance in bilingual and monolingual adults. As indicators of language experience, we focused on language context, typological proximity/distance between two languages and onset age of active bilingualism. As indicators of cognitive performance, we measured mixing costs and switching costs to gauge proactive and reactive control processes during a computerized non-verbal cognitive control task. Design/methodology/approach: Demographic and language data were collected with the Language and Social Background Questionnaire. Mixing and switching costs were subsequently obtained using a cued non-verbal switching task. Data and analysis: The background and switching-task data obtained from 60 bilinguals from non-English-speaking backgrounds and 24 English monolinguals residing in Australia were analysed using linear fixed-effects regression analyses. Findings/conclusions: The results showed that the use of two languages in a dual-language context was associated with reduced switching costs relative to monolingual and bilingual separated-language contexts and with reduced mixing costs only relative to a bilingual separated-language context. Among the bilinguals, lower mixing costs were also associated with an earlier onset age of active bilingualism and smaller typological distance between two languages. Originality: This study’s design included bilinguals as a target group and monolinguals as a control group, thus enabling the identification of possible mixing and/or switching cost advantages in bilinguals. By targeting young/middle-aged adults and considering a set of potentially relevant language experiences, this work was, therefore, well placed to provide clarity on findings for an age group that previously returned mixed and inconclusive results regarding a bilingual advantage. Significance/implications: Our findings reinforce the idea that particular dimensions of bilingual experience rather than bilingualism per se are linked to enhanced cognitive performance.

Dimensions of bilingualism promoting cognitive control

The study investigated the capacity of language experiences to predict cognitive performance of bilingual adults, with a special focus on participants’ proactive (mixing costs) and reactive (switching costs) control processes. Using a Language and Social Background Questionnaire, demographic and language data were collected from a linguistically diverse group of 60 bilingual adults residing in Australia. The participants were then tested on a non-verbal switching task. The results of multiple regressions revealed that two of the language variables being examined accounted for the variance in the mixing and switching costs. In particular, reduced mixing costs were related to the use of two languages in a dual-language context and earlier onset age of active bilingualism; reduced switching costs were linked to a dual-language context only. These findings reveal that bilingual experiences contribute to shaping proactive and reactive control processes across cognitive domains.

A Review of Passive Micromixers with a Comparative Analysis

A wide range of existing passive micromixers are reviewed, and quantitative analyses of ten typical passive micromixers were performed to compare their mixing indices, pressure drops, and mixing costs under the same axial length and flow conditions across a wide Reynolds number range of 0.01–120. The tested micromixers were selected from five types of micromixer designs. The analyses of flow and mixing were performed using continuity, Navier-Stokes and convection-diffusion equations. The results of the comparative analysis were presented for three different Reynolds number ranges: low-Re (Re ≤ 1), intermediate-Re (1 < Re ≤ 40), and high-Re (Re > 40) ranges, where the mixing mechanisms are different. The results show a two-dimensional micromixer of Tesla structure is recommended in the intermediate- and high-Re ranges, while two three-dimensional micromixers with two layers are recommended in the low-Re range due to their excellent mixing performance.

Bilingual language control across modalities

Bilingual language control has previously been tested separately in tasks of language comprehension and language production. Whereas these studies have suggested that local control processes are selectively recruited during mixed-language production, the present study investigated whether measures of global control show the same dependence on modality, or are shared across modalities. Thirty-eight Dutch-French bilingual young adults participated by completing two tasks of bilingual language control in both modalities. Global accuracy on mixed-language comprehension was related to mixing costs on bilingual verbal fluency, but only when compared to the L2-baseline. Global performance on mixed-language production was related to forward (L1-to-L2) switch costs. Finally, a significant correlation was found between the mixing cost on verbal fluency and forward switch costs on the comprehension task. The results are interpreted as evidence for the involvement of monitoring processes in bilingual language control across modality. The results also highlight the relevance of language switch directionality.