B04: Variability in bilingual language processing

This project examines how the processing of sentences and morphologically complex words in Turkish/German bilingual speakers is influenced by grammatical and non-grammatical factors.

A general conclusion from our studies on morphological processing is that the study of inter-individual variability leads to insights that remain hidden if only measures of central tendencies are evaluated. For example, we found that morphological parsing not only leads to faster processing, relative to control conditions, but also to more homogeneous performance, thus reducing inter-individual variability within a (bilingual) group of otherwise heterogeneous individuals.

In the domain of sentence processing, our experiments on non-categorical cases of subject-verb congruence in German and Turkish revealed some subtle differences between mono- and bilingual speakers. By using constraint-based models to model our results, we were able to gain insights into which of the factors determining monolingual language behaviour are also stable in bilingual language use and which are more variable.

Our experiments have brought us closer to the project's goal to develop models that can account for both variability and consistency in bilingual language processing.