Snakes and Ladders : Developmental Aspects of Lexical-Conceptual Relationships in the Multilingual Mental Lexicon

Sammanfattning: One phenomenon causing issues for language learners in the form of cross-linguistic influence (CLI) is translation ambiguity (Eddington & Tokowicz, 2013). Translation ambiguity refers to a situation where word meanings are different in a speaker’s languages. To give an example, Swedish does not lexicalize any difference between TO LEND and TO BORROW, whereas this distinction is made in English. Jiang (2002) proposed that language learners depend on explicit rules to resolve translation ambiguity. That is, based on Jiang’s predictions, a Swedish learner of English would have to consciously remember this difference to use the two English words successfully. Research in this area has focused on speakers with two languages. This thesis extends the research into third language acquisition. In this thesis, four empirical investigations are presented. Studies 1 and 2 focus on the initial state in L2 and L3 learners, respectively, of a Finnish-based pseudolanguage Kontu. Study 3 explored L1 German and L2 English naturalistic learners of L3 Swedish with longitudinal data from a beginner’s level until advanced fluency in the L3. Study 4 is a cross-sectional replication of Study 3. The present thesis represents a unique constellation of studies on CLI in late foreign language learners’ multilingual mental lexicon (MML) in that it presents data covering the very initial state all the way up to a high (≥ CEFR C1) proficiency. Moreover, it presents data from all six potential directions of CLI in L3 acquisition, in both accuracy and processing. Finally, all four studies investigated both forward and reverse CLI in the MML. Taking the results of the four studies together, CLI in the MML appears to be multidirectional. Both forward and reverse CLI was observed. The forward effects align with the predictions of the Parasitic Model (Hall & Ecke, 2003) for the initial stages as well as the RHM-TA overall (Eddington & Tokowicz, 2013). No indications of independence from the previously acquired languages in the L3 lexical representations were found. Also, the results indicate that the effects of translation ambiguity primarily occur in forward CLI at the item level, while the ob-served effects in reverse CLI were more global in nature in line with the predictions of Higby and colleagues (2020). For reverse CLI, there were differences between immersed and non-immersed learners. Furthermore, CLI operates differently in accuracy and processing. That is, a lack of overt effects does not imply the absence of CLI, which corroborates Jiang’s hypothesis. Finally, cognitive control, working memory, and psychotypology were all found to affect the learners’ behavior. The findings highlight the importance of considering the lack of conceptual non-equivalence in modeling multi-lingual lexical processing as well the importance of separating the effects of attrition from the effects of reverse CLI.