Does Language Dominance Affect Cognitive Performance In Bilinguals? Lifespan Evidence From Preschoolers Through Older Adults On Card Sorting, Simon, And Metalinguistic Tasks

This study explores the extent to which a bilingual advantage can be observed for three tasks in an established population of fully fluent bilinguals from childhood through adulthood. Welsh-English simultaneous and early sequential bilinguals, as well as English monolinguals, aged 3 years through older adults, were tested on three sets of cognitive and executive function tasks. Bilinguals were Welsh-dominant, balanced, or English-dominant, with only Welsh, Welsh and English, or only English at home. Card sorting, Simon, and a metalinguistic judgment task (650, 557, and 354 participants, respectively) reveal little support for a bilingual advantage, either in relation to control or globally. Primarily there is no difference in performance across groups, but there is occasionally better performance by monolinguals or persons dominant in the language being tested, and in one case-in one condition and in one age group-lower performance by the monolinguals. The lack of evidence for a bilingual advantage in these simultaneous and early sequential bilinguals suggests the need for much closer scrutiny of what type of bilingual might demonstrate the reported effects, under what conditions, and why.published_or_final_versio

Neural circuits of semantic and syntactic processing of Chinese and English

There is debate as to whether processing of semantic and syntactic information involves overlapping or separate neural circuits. Whereas some pinpoint Broca’s area (BA 44), as a syntactic processing site, and anterior LIFG as site for semantic processing (1,2), others propose involvement of posterior LIFG in meaning and syntax (4,5,6) or engagement of frontal cortices according to task demands. While in alphabetical languages, syntax and semantics are relatively independent mechanisms, Chinese presents little morphology and high semantic ambiguity and reliance on context, and more interdependence between syntax and semantics.This fmri study explored the neural circuits of semantic and syntactic processing, by asking speakers of Mandarin (who had English as their L2) to judge synctactic or semantic similarities in English and Chinese sentences. For both languages, overall activity for the whole task was shown in areas consistent with previous literature (i.e. left inferior frontal gyrus and posterior cerebellar lobes). Syntactic judgments in both languages were associated with higher activation visual processing areas (cuneus), while semantic judgments for both languages elicited activation in the caudate -a hypothetical centre for language control- (11). However, syntactic judgements in Chinese recruited additional activity in left middle temporal gyrus, consistent with studies showing that disruption of this area involves results in alexia and agraphia for Chinese characters (10). Syntactic judgments in Chinese elicited activation in areas associated with reading unambiguous characters (Left Insula, 12), conflict monitoring (Left cingulate, 13) and memory (parahippocampus, 14). However, syntactic judgments in English elicited activation in auditory/motor speech feedback areas (bilateral postcentral gyrus, 15), the right equivalent to Broca’s area, involved in processing semantic anomalies and in working memory (RMFG, 16) and in cerebellar tonsil, reported in previous studies (8). We argue that overall, syntactic judgements place more demands on higher visual processing areas, whereas semantic judgements might involve control of meaning retrieval. Furthermore, Chinese syntax judgments likely involve control mechanisms of semantic retrieval, whereas in English (the L2), participants are possibly aided by covert speech, and by involvement of part of the network responsible for the processing of Chinese sentence

Teasing apart factors influencing executive function performance in bilinguals and monolinguals at different ages

This study attempts to tease apart a variety of factors that may contribute to performance on executive function tasks. Data from the Simon task is re-examined to determine the contributions of age, SES, language proficiency/vocabulary, general cognitive performance, and bilingualism on performance. The results suggest influence from a variety of factors, with a major contribution from relative age and from language proficiency, as measured by vocabulary. Bilingualism showed some effect in relation to older adults’ accuracy of performance, in both congruent and incongruent conditions, but not to reaction time

Bilingualism and the semantic-conceptual interface: the influence of language on categorization

These studies address monolinguals' and bilinguals' processing of categories, in order to examine the relationship between concepts and linguistically encoded classes. We focus on languages that differ in their conceptual lexicalization and breadth of application, where one language has a single word (e.g., dedo in Spanish) that corresponds to two words in another language (e.g., English finger and toe). Categories differed across types of semantics-concept mappings, from ‘classical’ cases, involving members close in the conceptual space, to ‘homonyms’, involving conceptually distant items. Bilingual Catalan speakers, and English and Spanish monolinguals judged whether objects were ‘like’ an initial referent presented either with or without a label. Scores were highest in classical categories, lowest in homonyms; higher in narrow than wide categories; and better in labeled than unlabeled cases. Bilinguals outperformed monolinguals in judgments that conformed with their language, especially in wide categories. We discuss implications for the semantics-cognition interface and bilingualism