Beinan Zhou (University of Birmingham, UK) & Andrea Krott (University of Birmingham, UK)
Bilingual cognitive advantage; Semantic blocking; Lexical selection; Response distribution
It is generally agreed that target and non-target languages in bilingual speakers are concurrently active. This parallel activation poses the need to constantly monitor language production processes. It has been argued that this monitor mechanism recruits a domain general executive control network (e.g. Bialystok & Craik, 2010). As a result, bilingual speakers have been shown to outperform their monolingual counterparts in non-verbal tasks, especially in tasks that require to inhibit task irrelevant information (Bialystok, Craik, Green, & Gollan, 2009). However, little is known as to whether this advantage extends to the control within a language.
In the current study, we investigated whether being bilingual enhances speakers’ intra-language control when facing lexical competition. We utilized the cyclic semantic blocking paradigm (Kroll & Stewart, 1994). In this task participants repeatedly name pictures that are blocked into either same category objects (homogeneous condition, e.g. fish, mouse, snake, duck) or different category objects (heterogeneous condition, e.g. tie, snake, brush, lamp). This paradigm leads to slower responses in homogenous blocks than heterogeneous blocks. This is believed to be due to strong lexical competition in homogenous blocks.
We used ex-Gaussian analysis (Ratcliff, 1979) to inspect the distributions of the response times in different conditions. This analysis provides the mean of the leading edge of a distribution (μ), which represents the majority responses, and the mean/standard deviation of the tail of the distribution (τ), which represents extremely slow responses.
We tested monolingual English speakers, highly proficient English/Chinese bilingual speakers and proficient L2 speakers with English as L1. Results from a conventional analysis of variance of average responses in the two semantic homogeneity conditions suggest that all participants suffered from semantic competition to the same degree. However, the results of the ex-Gaussian analysis showed that the participant groups differed in their response distribution profiles. While monolingual speakers showed an effect of the semantic context only in the Gaussian part (μ) of their response distributions, bilingual and proficient L2 speakers showed an effect only in the exponential part (τ) of their response distributions. We argue that an enhanced top-down control mechanism that inhibits lexical competitors best explains the results.
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 Bialystok, E., Craik, F. I. M., Green, D. W., & Gollan, T. H. (2009). Bilingual minds. Psychological Science in the Public Interest, 10(3), 89-129.
 Kroll, J. F., & Stewart, E. (1994). Category interference in translation and picture naming: Evidence for asymmetric connection between bilingual memory representations. Journal of Memory and Language, 33(2), 149-174.
 Ratcliff, R. (1979). Group reaction-time distributions and an analysis of distribution statistics. Psychological Bulletin, 86(3), 446-461. doi: 10.1037/0033-2909.86.3.446