SELECTIVITY IN LEXICAL ACCESS AMONG BILINGUALS OF ORTHOGRAPHICALLY DISTINCT SCRIPTS AND THE ROLE OF EXECUTIVE FUNCTIONS
Al Thowaini, Buthainah M
MetadataShow full item record
A fundamental inquiry within bilingual processing research addresses the underlying mechanisms of lexical access. Research involving bilinguals of orthographically similar scripts has revealed that cross-language activation is non-selective, which supposedly causes the bilingual brain to regularly manage the activation of two languages. Such continuous management of two languages has led some researchers to argue that the bilingual experience contributes to enhanced executive control. The research on selectivity in lexical access, nevertheless, has overwhelmingly involved bilingual speakers of orthographically similar scripts, with a scarcity of studies involving bilingual speakers of orthographically distinct scripts. Additionally, while active management of both languages is expected for bilinguals, little is known about whether language selectivity is related to individual variation in executive control. Instead, research investigating executive functions (EFs) in relation to bilingual processes has primarily been conducted within the context of switch costs, which has been associated with methodological issues. In light of the issues outlined above, the current study investigated selectivity in lexical access among bilinguals of orthographically distinct scripts and the relationship between the degree of selectivity and EFs (i.e., top-down goal maintenance, interference resolution, and working memory capacity). In addition to adopting an individual differences approach to lexical access, the study manipulated the degree of language task demands (comprehension and production). The study employed alternative non-switch tasks to investigate the relationships between EFs and cross-language activation. One hundred and thirty-eight Arabic-English bilinguals, 25 English native speakers, and 24 Arabic native speakers participated in a phoneme monitoring task and a masked primed lexical decision task involving monolingual materials. Bilingual participants also completed non-verbal visuo-spatial and visual single n-back tasks, as well as an AX-CPT task. The analyses revealed non-selective lexical access in language production but were inconclusive for language comprehension, where participants varied in the degree of selectivity. In addition, the results, although preliminary, demonstrated that top-down goal maintenance partially accounted for some of the variances in the degree of selectivity in language comprehension and production. The results suggest that selectivity is influenced by task-dependent variables as well as individual differences in executive functions.