Bilingualismus: eine Herausforderung für das sich entwickelnde Gehirn

Zusammenfassung

Der Einsatz neurophysiologischer Methoden in der Bilingualismus-Forschung zeigte – entgegen ursprünglicher Annahmen –, dass bilinguale SprecherInnen nicht notwendigerweise andere neuronale Regionen für die Sprachverarbeitung aktivieren als monolinguale SprecherInnen. Faktoren wie die Kompetenz in einer Zweitsprache (L2) und das Alter bei Beginn des L2-Erwerbs können allerdings die Repräsentation der L2 im „bilingualen Gehirn“ beeinflussen. So wurde ein späterer Erwerbsbeginn, verglichen mit einem frühen Start in die Zweisprachigkeit, vielfach mit einer geringeren L2-Kompetenz und mit differierenden neurophysiologischen Aktivierungsmustern für sprachbezogene Aufgaben in Verbindung gebracht. Die bilinguale Forschung mit engem Bezug zu neurowissenschaftlichen Disziplinen konzentrierte sich diesbezüglich bis dato jedoch weitgehend auf sprachliche Fähigkeiten im Erwachsenenalter und beschäftigte sich erst in ihrer jüngsten Entwicklung zunehmend mit dem Erwerbsverlauf sprachlicher Fähigkeiten. Die Ergebnisse unserer Langzeitbeobachtung an 3 bilingualen Kindern, die alle gleich lange und unter vergleichbaren Umständen ihre Zweitsprache lernten, deuten auf einen Zusammenhang zwischen dem Alter zu Beginn des Erwerbs und den grammatikalischen Fähigkeiten in der L2 hin; Wortschatz und Lesefähigkeit scheinen hingegen nicht mit dem Alter bei Erwerbsbeginn zusammenzuhängen. Weiters reagierte das L2-Sprachsystem des ältesten Kindes am stabilsten auf eine vorübergehende Veränderung der sprachlichen Umgebung. Um jedoch generalisierte Aussagen über linguo-kognitive Entwicklungsverläufe bei Kindern und Jugendlichen, die gleichzeitig mehrere Sprachen erlernen, treffen zu können, bedarf es weiterer interdisziplinärer Forschungsbestrebungen zum sich entwickelnden „multilingualen Gehirn“.

Abstract

Neurophysiological studies have demonstrated that first language (L1) and second language (L2) processing are not necessarily represented in different neural regions. However, factors such as language competence and age at onset of L2 acquisition can influence the representation of L2 in the “bilingual brain”. Bilinguals who acquired a second language later in life were frequently reported as having different activation patterns for linguistic tasks as compared to bilinguals with an early age at onset of L2 acquisition. Furthermore, later acquisition of L2 has often been associated with a poorer language outcome. Previous neuroscientific research on bilinguals primarily addressed the language outcome of bilinguals in adolescence and adulthood, but there remains a significant gap in knowledge regarding the developmental trajectory of language capacities that has only recently started to be systematically addressed. The current longitudinal study presents an examination of 3 bilingual children with the same duration of bilingual language exposure but different ages at onset of L2 acquisition. Our observations indicate a relationship between the age at onset of acquisition and the grammatical competence of L2 later in life. However, lexicon and reading competence were not influenced by age at onset of L2 acquisition. Furthermore, the L2 system of the child who was the oldest at the onset of L2 acquisition displayed the most robustness after a temporary change in linguistic environment. To generalize these findings and detect general developmental trends in children acquiring 2 or more languages at a time, more interdisciplinary research on the developing “multilingual brain” is needed.

Schlüsselwörter

Bilingualismus - Eye-Tracking - Schriftspracherwerb - Spracherwerb

Key words

bilingualism - eye tracking - literacy acquisition - language acquisition

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