Learning the easy way: the role of form similarity in language learning and processing

Abstract

A key question about bilingual lexical access is whether lexical representations are activated selectively (within one language) or non-selectively (across languages). A great deal of the research addressing this question has focused on cognates, translation equivalents with the same or similar forms across languages. These studies show that, in non-native language (L2) processing, cognates are usually recognised and produced faster than non-cognates, suggesting that the form overlap between translation equivalents contributes to a processing advantage. Traditionally, the advantage is assumed to demonstrate on-line non-selective activation: For cognates, lexical activation stems from two sources rather than one, as is the case with non-cognates. This converging activation leads to their facilitated processing. However, some researchers argue that cognate facilitation could be due to differences in how cognates and non-cognates are learned, which leads to qualitatively different representations for cognates.

In this thesis, I focus on learning-based explanations of cognate effects and ask to what extent these can account for cognate facilitation. First, I review findings of cognate effects in both comprehension and production, evaluating whether they are more consistent with learning-based or on-line accounts. Second, I explore whether neural language models trained on two languages exhibit cognate facilitation and use this to test learning-based hypotheses of the effect. Following this, I present two behavioural experiments investigating cognate effects in human non-native speakers. The first investigates how the language of instruction affects cognate facilitation in trilinguals to examine whether cognate effects only occur between languages involved in learning. The second tests whether bilinguals exhibit cognate effects in L2 prediction to shed light on whether predictive processing is language selective. Taken together, this thesis provides evidence that cognate facilitation can, in principle, be explained by learning. I argue that while non-selective activation may occur during on-line processing, it is not required to explain cognate effects. I call for a more nuanced approach to theories of bilingual lexical access that allow for a more flexible role for language selectivity.