Following Spoken Instructions in L1 and L2: The Effects of Language Dominance, Working Memory, Cognitive Complexity, and Language Acquisition Background

Abstract

This thesis investigates cognitive aspects of following spoken instructions in bilinguals’ dominant and non-dominant languages. The aim was to increase our understanding of the cognitive benefits and costs of information processing and performance in a second language (L2) compared with a first language (L1). I hypothesized that L2 tasks are associated with more computational and cognitive costs, even in highly proficient bilinguals. In three empirical studies, I examined to what extent factors such as the language of task, working memory capacity, phonological memory, and variables in bilinguals’ language history affect processing and performance of sequences of oral instructions in L1 and L2. Furthermore, I manipulated the psycholinguistic complexity of sequential temporal order to see how it influences bilinguals’ processing and performance, and how it interacts with other variables. Contrary to similar monolingual studies, I tested bilingual participants in two separate sessions, and applied mixed effects logistic regression models to analyze the data. The results suggest that language dominance significantly affects bilinguals’ processing and performance of sequential verbal instructions, with a disadvantage for tasks presented in the non-dominant language. Bilinguals’ recall accuracy was consistently superior when the target sentences were presented in L1. Working memory capacity and phonological memory correlated with instruction-following abilities, especially, in less-proficient bilinguals. Individuals with more available working memory resources were more likely to have better processing and performance in following sequences of spoken instructions. The psycholinguistic complexity of temporal order expressions affected the ability to follow sequential oral instructions, causing lower recall accuracy when the surface order of events was incongruent with the factual order of events in complex instructions. A number of variables in bilinguals’ language background, specifically the age of initial L2 acquisition, level of L2 proficiency, L2 use, and L2 exposure also predicted performance, especially, in less-skilled bilinguals. To the best of my knowledge, this is the first empirical study that has investigated the effects of using a non-dominant language on following instructions modelled on real-world tasks in an office workplace.