Language control in bilingual language comprehension: evidence from the maze task.

Xin Wang

doi:10.3389/fpsyg.2015.01179

Abstract

Most empirical evidence on switch costs is based on bilingual production and interpreted as a result of inhibitory control. It is unclear whether such a top–down control process exists in language switching during comprehension. This study investigates whether a non-lexical switch cost is involved in reading code-switched sentences and its relation to language dominance with cross-script bilingual readers. A maze task is adopted in order to separate top–down inhibitory effects, from lexical effects driven by input. The key findings are: (1) switch costs were observed in both L1–L2 and L2–L1 directions; (2) these effects were driven by two mechanisms: lexical activation and inhibitory control; (3) language dominance modulated the lexical effects, but did not affect the inhibitory effects. These results suggest that a language control mechanism is involved in bilingual reading, even though the control process is not driven by selection as in production. At the theoretical level, these results lend support for the Inhibitory Control model during language switching in comprehension; while the BIA/BIA+ model needs to incorporate a top–down control mechanism to be able to explain the current findings.

Highlights

Code-switching (CS) is a common and natural occurrence in multilingual societies which, due to language contact, has existed for centuries
If there was an inhibitory effect apart from the lexical effect involved in reading CSs, one would expect a significant delay in Region 3 across switch vs. non-switch conditions
In the current design, one would predict an inhibitory effect observed in Region 3 if the control processes were involved in reading code-switches, as well as lexical effects in Region 2 potentially confounded by inhibitory effects

Summary

Introduction

Code-switching (CS) is a common and natural occurrence in multilingual societies which, due to language contact, has existed for centuries. Studies have demonstrated significantly slower reaction times (RTs) when bilinguals switched languages between items in a picture- or number-naming task, compared to when they named non-switched trials (e.g., Meuter and Allport, 1999; Costa and Santesteban, 2004; Costa et al, 2006). In a non-switch trial, subjects named the numerals in the same language twice in a row, while a switch trial required them to switch from one language to the other. Their RTs for switch trials were significantly slower than for non-switch trials, suggesting the presence of a switch cost.

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