Neural Switching Mechanism in the late Korean-English bilinguals by Event-Related fMRI
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Functional MRI technique was used in this study for examining the language switching mechanisms between the first language (L1) and the second language (L2). Language switching mechanism is regarded as a complex task that involves an interaction between L1 and L2. The aim of study is to find out the brain activation patterns during the phonological process of reading real English words and English words written in Korean characters in a bilingual person. Korean-English bilingual subjects were examined while they covertly read four types of words native Korean words, Korean words of a foreign origin, English words written in Korean characters, and English words. The fMRI results reveal that the left hemispheric language-related regions at the brain, such as the left inferior frontal, superior temporal, and parietal cortices, have a greater response to the presentation of English words written in Korean characters than for the other types of words, in addition, a slight difference was observed in the occipital-temporal lobe. These results suggest that a change in the brain circuitry underlying the relational processes of language switching is mainly associated with general executive processing system in the left prefrontal cortex rather than with a similarity-based processing system in the occipital-temporal lobes.
Abstract
Functional MRI technique was used in this study for examining the language switching mechanisms between the first language (L1) and the second language (L2). Language switching mechanism is regarded as a complex task that involves an interaction between L1 and L2. The aim of study is to find out the brain activation patterns during the phonological process of reading real English words and English words written in Korean characters in a bilingual person. Korean-English bilingual subjects were examined while they covertly read four types of words native Korean words, Korean words of a foreign origin, English words written in Korean characters, and English words. The fMRI results reveal that the left hemispheric language-related regions at the brain, such as the left inferior frontal, superior temporal, and parietal cortices, have a greater response to the presentation of English words written in Korean characters than for the other types of words, in addition, a slight difference was observed in the occipital-temporal lobe. These results suggest that a change in the brain circuitry underlying the relational processes of language switching is mainly associated with general executive processing system in the left prefrontal cortex rather than with a similarity-based processing system in the occipital-temporal lobes.
참고문헌 (26)
- S.E. Petersen, "Position emission tomographystudies of the cortical anatomy of single-word processing", Nature, 331, pp.585~589 (1988)
- D. Klein, "The neural substrates underlying word generation: a bilinguals functional-imaging study", Proc. Natl. Acad. Sci. U.S.A, 92, pp.2899~2903 (1995), a bilinguals functional-imaging study,Proc.Natl.Acad.Sci.U.S.A.,vol.92,pp.2899-2903
- K.H. Kim, "Distinct cortical areas associated with native and second languages", Nature, 388, pp.171~174 (1997)
- M.W. Chee, "Mandarin and English single word processing studied with functional magnetic imaging", J.Neurosci, 19, pp.3050~3056 (1999)
- A.E. Hernandez, "In search of the language switching: an fMRI study of picture naming in Spanish- English bilinguals", Brain Lang, 73, pp.421~431 (2000)
- D. Klein, "Bilingual brain organization: A functional magnetic resonance adaptation study", NeuroImage, 31, pp.366~375 (2006)
- C.J. Price, "A functional imaging study of translation and language switching", Brain, 122, pp.2221~2235 (1999)
- S. Dehaene, "Anato- mical variability in the cortical representation of first and second language", NeuroReport, 8, pp.3809~3815 (1997)
- D. Perani, "The bilingual brain. Proficiency and age of acquisition of the second language", Brain, 121, pp.1841~1852 (1998)
- J.F. Kroll, "Category Interference in Switching and Picture Naming: Evidence for Asymmetric Connections Between Bilingual Memory Representations", J. Mem. Lang, 33, pp.149~174 (1994)
- E.A. Hirshorn, "Role of the left inferior frontal gyrus in covert word retrieval: Neural correlates of switching during verbal fluency", NeuroPsychologia, 44, pp.2547~2557 (2006)
- O. Josephs, "Event-related fMRI: modeling, inference and optimization", Phil. Trans. R. Soc. Lond, 354, pp.1215~1228 (1999)
- K.J. Friston, "Event-related fMRI: characterizing differential response", NeuroImage, 7, pp.30~40 (1998)
- N. Tzourio-Mayzoyer, "Automated anatomical labeling of activations in SPM using a macroscopic anatomical parcellation of the MNI MRI single-subject brain", NeuroImage, 15, pp.273~289 (2002)
- G.F. Eden, "Neural changes following remediation in adult developmental dyslexa", Neuron, 44, pp.411~422 (2004)
- P.G. Simons, "Cerebral mechanisms involved in word reading dyslexic children: magnetic source imaging approach", Cereb. Cortex, 10, pp.809~816 (2000)
- P.E.Turkeltaub, "Development of neural mechanisms for reading", Nat.Neurosci, 6, pp.767~773 (2003)
- L.E.Cutting, "Differential compon-ents of sentence comprehension:beyond single word reading and memory", NeuroImage, 29, pp.429~438 (2006)
- S.Bookheimer, "Functional MRI of language:new approaches to understanding the cortical organization of semantic processing", Annu.Rev.Neurosci, 24, pp.151~188 (2002)
- C.J.Price, "Segregating semantic from phonological processes during reading", J.Cogn.Neurosci, 96, pp.727~733 (1997)
- M.H.Lehtonen, "Brain correlates of sentence switching in Finnish-Norwegian bilinguals", Neuroreport, 16, pp.607~610 (2005)
- S.Valdois, "Polysyllable pseudo-word processing in reading and lexical decision:converging evidence from behavior data,connectionist simulations and functional MRI", Brain Res, 1085, pp.149~162 (2006)
- S.M.Kosslyn, "Evidence for two types of spatial representations:hemispheric specialization for categorical and coordinate relat-ions", J.Exp.Psychol.Hum.Percept.Perform, 15, pp.723~735 (1989)
- M.H.Davis, "Neural respon-ses to morphological,syntactic,and semantic properties of single words:An fMRI study", Brain lang, 89, pp.439~449 (2004)
- M.Lehtonen, "Recog-nition of inflected words in a morphologically limited language:frequency effects in monolinguals and bilinguals", J.Psycholin-guist Res, 35, pp.121~146 (2006)
- H.Kim, "Dissociation of pure Korean words and Chinese-derivative words in phonological dysgraphia", Brain Lang, 74, pp.134~137 (2000)