Reduced frontal activation with increasing 2nd language proficiency

• Published in: Neuropsychologia Vol. 47; no. 13; pp. 2712 - 2720
• Main Authors: Stein, Maria, Federspiel, Andrea, Koenig, Thomas, Wirth, Miranka, Lehmann, Christoph, Wiest, Roland, Strik, Werner, Brandeis, Daniel, Dierks, Thomas
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2009; Elsevier
• Subjects: Adolescent; Adolescent Behavior - physiology; Anatomical correlates of behavior; Behavioral psychophysiology; Bilingualism; Bilingualism. Multilingualism; Biological and medical sciences; Brain Hemisphere Functions; Brain Mapping; Cortical plasticity; Diagnostic Tests; English; Exchange Programs; Female; fMRI; Foreign Students; Frontal Lobe - physiology; Functional Magnetic Resonance Imaging; Fundamental and applied biological sciences. Psychology; German; German as a Second Language Learning; High School Students; Humans; Inferior frontal gyrus; Language; Language Acquisition; Language Processing; Language Proficiency; Lexico-semantic processing; Longitudinal Studies; Magnetic Resonance Imaging; Male; Multilingualism; Native Language; Native Speakers; Neural Basis of Language; Oral Reading; Practice (Psychology); Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - physiology; Second Language Learning; Semantic Processing; Semantics; Time Factors; Vocabulary; fMRI; Bilingualism; Cortical plasticity; Lexico-semantic processing; Inferior frontal gyrus; Human; Cerebral cortex; Central nervous system; Cognition; Activation; Frontal cortex; Nuclear magnetic resonance imaging; Encephalon; Verbal ability; Language; Semantics; Plasticity; Information processing; Functional imaging
• ISSN: 0028-3932; 1873-3514; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2009.05.023

The factors influencing the degree of separation or overlap in the neuronal networks responsible for the processing of first and second language are still subject to investigation. This longitudinal study investigates how increasing second language proficiency influences activation differences during lexico-semantic processing of first and second language. Native English speaking exchange students learning German were examined with functional magnetic resonance imaging while reading words in three different languages at two points in time: at the beginning of their stay (day1) and 5 months later (day2), when second language proficiency had significantly increased. On day1, second language words evoked more frontal activation than words from the mother tongue. These differences were diminished on day2. We therefore conclude that with increasing second language proficiency, lexico-semantic processing of second language words needs less frontal control. Our results demonstrate that lexico-semantic processing of first and second language converges onto similar networks as second language proficiency increases.