Does bilingualism affect the morphological processing of Turkish derived words? Insight from Turkish-English bilinguals

It has been suggested that native speakers may develop different processing patterns in their first language (L1) as they become proficient second language (L2) users. While most of the studies are conducted with heritage speakers whose L1 is the minority language in the society, the number of studies that investigate L1 as the majority language is scarce. These studies have shown that a high proficiency foreign language can influence native language processing even in the L1 context in the domain of lexicon (van Hell & Dijkstra, 2002) and morphological processing (Uygun & Gürel, 2020).

The aim of the present study is to investigate the potential changes in Turkish-English late bilinguals’ processing of L1 derived words, as this will provide valuable insights into the processing of morphologically complex words in the bilingual mental lexicon. The two main models proposed for morphological processing are decomposition (i.e. parsing into constituent morphemes) and full-listing (i.e. whole word storage).

In the present study, 61 monolingual Turkish speakers and 40 Turkish-English late bilingual speakers were tested by using a masked priming experiment. All late bilingual speakers had a high proficiency in English. 66 words that made up the stimuli were separated into three categories: (i) transparent words (dalga ‘wave’, dal ‘dive’ and –ga ‘derivational suffix’), (ii) opaque words (karga ‘crow’, kar ‘snow’ but –ga does not function as derivational suffix), (iii) form/control words (devre ‘period’, dev ‘giant’, –re is not a derivational suffix). Primes were either related or unrelated to the target word and they were presented for 42 seconds.

The preliminary results indicate no significant group differences in the morphological processing of Turkish derived words. While both monolingual and Turkish-English late bilingual speakers employed decomposition for transparent and opaque words, no decomposition was observed for the form/control words. These results suggest that not only monolingual but also Turkish-English late bilingual speakers use decomposition and the transparency of the derived word does not influence the processing route, indicating no influence of high L2 proficiency on the morphological processing of L1.