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

• Literatur

• 1 Sanz C. Bilingual education enhances third language acquisition: evidence from Catalonia. Appl Psycholinguist 2000; 21: 23-44
• 2 Bialystok E, Viswanathan M. Components of executive control with advantages for bilingual children in two cultures. Cognition 2009; 112: 494-500
• 3 Sachse S, Budde N, Rinker T et al. Mehrsprachige Kinder in vorschulischen Sprachfördermaßnahmen – soziodemografischer Hintergrund und Sprachleistungen. LOGOS Interdiszip 2010; 18: 337-345
• 4 Scoresby-Jackson R. Case of aphasia with right hemiplegia. Edinb Med J 1867; 12: 696-706
• 5 Broca P. Remarques sur le siége de la faculté du langage articulé, suivies d’une observation d’aphémie (perte de la parole). Bull Soc Anat 1861; 6: 330-357
• 6 Pitres A. Aphasia in polyglots. In: Paradis M. (ed.). Readings on Aphasia in Bilinguals and Polyglots. Montreal: Didier; 1895: 26-49
• 7 Albert ML, Obler LK. The bilingual Brain: neuropsychological and neurolinguistic Aspects of Bilingualism. New York: Academic Press; 1978
• 8 Karanth P, Rangamani GN. Crossed aphasia in multilinguals. Brain Lang 1988; 34: 169-180
• 9 Park HRP, Badzakova-Trajkov G, Waldie KE. Language lateralisation in late proficient bilinguals: a lexical decision fMRI study. Neuropsychologia 2012; 50: 688-695
• 10 Friederici AD. The brain basis of language processing: from structure to function. Physiol Rev 2011; 91: 1357-1392
• 11 Friederici AD. Language development and the ontogeny of the dorsal pathway. Front Evol Neurosci 2012;
• 12 Friederici AD, Brauer J, Lohmann G. Maturation of the language network: from inter- to intrahemispheric connectivities. PLoS ONE 2011; 6: e20726
• 13 Geschwind N. Disconnection syndromes in animals and man. Brain 1965; 88: 237-294
• 14 Kronbichler M, Hutzler F, Staffen W et al. Evidence for a dysfunction of left posterior reading areas in German dyslexic readers. Neuropsychologia 2006; 44: 1822-1832
• 15 Price CJ. The anatomy of language: a review of 100 fMRI studies published in 2009. Ann N Y Acad Sci 2010; 1191: 62-88
• 16 Wahl M, Marzinzik F, Friederici AD et al. The role of the human thalamus in syntactic language processing. Neuron 2008; 59: 695-707
• 17 Abutalebi J. Neural aspects of second language representation and language control. Acta Psychol 2008; 128: 466-478
• 18 Perani D, Paulesu E, Galles NS et al. The bilingual brain. Proficiency and age of acquisition of the second language. Brain 1998; 121: 1841-1852
• 19 Chee MWL, Hon N, Lee HL et al. Relative language proficiency modulates BOLD signal change when bilinguals perform semantic judgments. Neuroimage 2001; 13: 1155-1163
• 20 Hernandez AE, Meshyan G. Executive function is necessary to enhance lexical processing in a less proficient L2: evidence from fMRI during picture naming. Biling Lang Cogn 2006; 9: 177-188
• 21 Weber-Fox CM, Neville HJ. Maturational constraints on functional specializations for language processing: ERP and behavioural evidence on bilingual speakers. J Cogn Neurosci 1996; 8: 231-256
• 22 Wartenburger I, Heekeren HR, Abutalebi J et al. Early setting of grammatical processing in the bilingual brain. Neuron 2003; 37: 159-170
• 23 Pakulak E, Neville HJ. Maturational constraints on the recruitment of early processes for syntactic processing. J Cogn Neurosci 2011; 23: 2752-2765
• 24 Neville HJ, Nicol JL, Barss A et al. Syntactically based sentence processing classes: evidence from event-related brain potentials. J Cogn Neurosci 1991; 3: 151-165
• 25 Mechelli A, Crinion JT, Noppeney U et al. Neurolinguistics: structural plasticity in the bilingual brain. Nature 2004; 431: 757
• 26 Mohades SG, Struys E, Van Schuerbeek P et al. DTI reveals structural differences in white matter tracts between bilingual and monolingual children. Brain Res 2012; 1435: 72-80
• 27 Marschik PB, Einspieler C, Garzarolli B et al. Events at early development: are they associated with early word production and neurodevelopmental abilities at the preschool age?. Early Hum Dev 2007; 83: 107-114
• 28 Mayberry RI, Lock E, Kazmi H. Linguistic ability and early language exposure. Nature 2002; 417: 38
• 29 Johnson JS, Newport EL. Critical period effects in second language learning: the influence of maturational state on the acquisition of English as a second language. Cogn Psychol 1989; 21: 60-99
• 30 Judaš M, Cepanec M. Adult structure and development of the human fronto-opercular cerebral cortex (Broca’s region). Clin Linguist Phon 2007; 21: 11-12
• 31 Karmiloff-Smith A. Neuroimaging of the developing brain: taking “developing” seriously. Hum Brain Mapp 2010; 31: 934-941
• 32 De Houwer A. Parental language input patterns and children’s bilingual use. Appl Psycholinguist 2007; 28: 411-424
• 33 Kovelman I, Baker SA, Petitto L-A. Age of first bilingual language exposure as a new window into bilingual reading development. Biling (Camb Engl) 2008; 11: 203-223
• 34 Hutzler F, Wimmer H. Eye movements of dyslexic children when reading a regular orthography. Brain Lang 2004; 89: 235-242
• 35 Bartl-Pokorny KD, Landerl K, Einspieler C et al. Dyslexie und ihre neuronale Signatur. Klin Neurophysiol 2011; 42: 166-171
• 36 Teoh WQ, Brebner C, McCormack P. Assessing the language skills of children from culturally and linguistically diverse backgrounds: the expressive vocabulary performance of Singaporean English-Mandarin bilingual pre-schoolers. Int J Speech Lang Pathol 2012;