Grace Cannon & Hanako Yoshida (University of Houston)
Child development; Bilingualism; Task-switching; Working memory; Semantic processing; Cross-modality cueing
Previous research concerning bilingual and monolingual differences is inconsistent in findings of bilingual advantages across different types of cognitive control (CC) tasks (1). Certain studies indicate that differences in CC occur solely due to working memory (WM) ability, not bilingualism (2), while others maintain that the bilingual experience provides a specific advantage to CC beyond other influences (3). Advantages found in bilingual CC are attributed to language-specific processes, including attention, inhibition, and switching in multiple languages (4). Thus, these advantages may be affected by CC tasks that provide different amounts of language information. The goals of the current research are (1) Examine CC differences in monolingual and bilingual children receiving varied on-line language input within a task; and (2) Identify relationships of verbal and nonverbal WM with CC as language input varies.
The current study varied language input by manipulating the Semantic, Visual, and Auditory content in four conditions of the Dimensional Change Card Sort (DCCS; 5), which has demonstrated a robust bilingual advantage in many previous studies (6): Nonsemantic (Shape/Color sorting), Visual-Semantic (Kind/Color sorting with pictures of foods and animals), Auditory-Semantic (Kind/Color sorting with spoken names), and Both-Semantic Visual and Auditory (Kind/Color with pictures and names). Verbal and Spatial WM were also tested to examine alternative explanations for bilingual differences. We tested 26 4-5 year old children, who tend to have difficulty with switching between sorting types (e.g., Shape/Color) in a mixed block. Importantly, this age group has primarily had language input in the auditory domain, so auditory information is particularly important to the development of any bilingual advantages up to this point. We hypothesized that (1) Task-specific language input will interact with bilingualism: Bilinguals will show the greatest CC advantage when given only verbal information; and (2) Verbal and non-verbal WM will predict CC only for tasks that involve the same domain.
Results showed a bilingual advantage in switching costs between incongruent and congruent trials. However, this occurred due to higher monolingual accuracy on congruent trials, not any bilingual advantage on incongruent trials. Language-input condition predicted accuracy on congruent trials: children were more accurate on Visual- and Auditory-Semantic conditions compared to Both-Semantic and Nonsemantic conditions.
Verbal WM predicted higher accuracy for congruent trials. Spatial WM interacted with Language-input condition for reaction time (RT) on incongruent trials, but not on congruent trials, when testing only accurate trials; Spatial WM also interacted with DCCS condition for RT trial switch cost when all trials were included; Better spatial WM predicted slower incongruent RT and larger RT costs for the Nonsemantic condition, but not for any of the three Semantic (language-based) conditions.
Implications are discussed in terms of understanding mechanisms of bilingual differences and relationships between language, cognitive control, and working memory.
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