Morphological complexity modulates morphological processing: evidence from cross-language embedded stem priming in French-English bilinguals

Purpose: The dynamic interaction between the two languages of a bilingual (L2) reader is a well-documented phenomenon in psycholinguistic literature on L2 processing. However, the effects of morphological complexity and orthographic transparency on cross-language transfer between similar-script languages remain unclear. The present study intended to address this question using a cross-language complex nonword priming paradigm in a lexical decision task. Methods: In a lexical decision task, 101 late L1 French-L2 English bilinguals (42 females, age: M = 31.4, SD = 8.4, range = 18–50) responded to English stem targets (e.g. TREE) preceded by three types of L1 French stimuli: affixed nonwords (e.g. arbreur [treeness], non-affixed nonwords (e.g. arbrux [treew]), or unrelated nonwords (e.g. mondese [worldew]). Participants additionally took the English LexTale test and completed a short version of the Language Experience and Proficiency Questionnaire. Results: The results revealed significant cross-language embedded stem priming relative to an unrelated condition. A comparison of the present data with that of the speakers of Turkish, a highly morphological complex agglutinative system, showed that the morphological complexity of bilinguals’ L1 indeed modulates cross-language morphological priming, which was entirely absent in French, a less morphologically complex system. Conclusion: This study confirms the presence of cross-language embedded word priming effects in similar-script bilinguals. It also provides the first evidence that cross-linguistic factors impact bilinguals’ ability to process and identify affixes in reading, using cross-language stimuli.