Plasticity of grammatical recursion in German learners of Dutch

Abstract

Previous studies have examined cross-serial and embedded complement clauses in West Germanic in order to distinguish between different types of working memory models of human sentence processing, as well as different formal language models. Here, adult plasticity in the use of these constructions is investigated by examining the response of German-speaking learners of Dutch using magnetoencephalography (MEG). In three experimental sessions spanning their initial acquisition of Dutch, participants performed a sentence-scene matching task with Dutch sentences including two different verb constituent orders (Dutch verb order, German verb order), and in addition rated similar constructions in a separate rating task. The average planar gradient of the evoked field to the initial verb within the cluster revealed a larger evoked response for the German order relative to the Dutch order between 0.2 to 0.4 s over frontal sensors after 2 weeks, but not initially. The rating data showed that constructions consistent with Dutch grammar, but inconsistent with the German grammar were initially rated as unacceptable, but this preference reversed after 3 months. The behavioural and electrophysiological results suggest that cortical responses to verb order preferences in complement clauses can change within 3 months after the onset of adult language learning, implying that this aspect of grammatical processing remains plastic into adulthood.

Keywords:

• Language learning
• Linguistic complexity
• Plasticity
• Recursion
• Sentence processing

Acknowledgements

This work was supported by the Dutch science foundation Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) and the German science foundation Max-Planck-Gesellschaft (MPG). Frauke Hellwig recruited subjects and provided the set of German materials and matching graphical displays, as well as the grammatical rating stimuli. The analysis of the MEG data was made possible by the Fieldtrip toolbox, available at http://www.ru.nl/neuroimaging/fieldtrip/. We would like to acknowledge the helpful comments of two anonymous reviewers of this manuscript. An earlier version of this work benefited from additional comments and several anonymous reviews at the 9th International Workshop on Tree Adjoining Grammars and Related Formalisms in Tübingen, Germany.