從大腦神經機制來探討第二語言數位學習的成效：以中文詞彙聲調區辨敏感性的功能性神經反應為例
No Thumbnail Available
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
數位時代中全球化的環境促進雙語學習的興起，應用數位科技學習第二語言儼然是不可避免的趨勢。從認知神經科學觀點來探究數位學習的成效，除了在傳統數位學習研究的行為觀察資料之外，同時運用非侵入性的腦神經造影技術，得以進一步觀察學習效果的內在神經機制，在大腦神經可塑性(brain neural plasticity)的前提下，進一步描繪學習(learning)的本質。本研究以中文為第二語言 (Chinese as a second language, CSL) 的學習為例，探討CSL初學者學習前後大腦對於中文詞彙聲調(lexical tone)的神經功能性反應的學習成效。本研究採用受試者內(within-subjects)前後測實驗設計，以測驗時間為自變數，前後測成績及前後測所量測的大腦對於中文詞彙聲調變化的不匹配負波腦磁反應(magetic correspondent of mismatch negative, MMNm)為依變數，進行變異數分析，以了解學習成效。研究結果顯示，非聲調母語者採用會話句子情境的數位學習平台，在會話的語境脈絡中學習字詞的形音義，屬於非聲調區辨特定作業的訓練，進行每天1小時為期3天的短期自主學習，學習後句子聽讀測驗成績表現顯著優於前測, 同時，腦磁圖的實驗數據顯示，學習後能夠提升CSL初學者的中文詞彙聲調區辨的敏感性；亦即學習後大腦對於大差異T3/T1的MMNm反應比小差異T3/T2的MMNm反應來得大且快，呈現學習後大腦神經反應有類母語者(native-like)的樣態。並且MMNm反應源分析結果顯示，左腦聽覺皮質的Heschl’s Gyrus(HG)和左腦額葉的Insula在學習後對於大差異T3/T1都有顯著活化的反應，可以據以推論學習改變了學習者對於詞彙聲調的處理機制，從非聲調母語既定的依賴右腦主宰物理性聲學資訊的處理模式(predisposed acoustic-dependent lateralization)，隨著感知到中文詞彙聲調蘊含的語言特徵後，轉換遷移到左腦負責語音聲韻(phonological)資訊的處理，呼應了語音與非語音的雙聯知覺(duplex perception)處理機制，符合功能性假說(functional-dependent lateralization)，且驗證大腦語言處理左側化及大腦神經可塑性的假說。總而言之，本研究連結「行為—大腦」實證性數據，以創新的觀點來闡述學習的本質，對於第二語言數位學習模式提供一項具有學習成效的實證範例。
In a digital age, bilingual learning is currently pervasive in globalization society and is inevitably facilitated by learning technology. In order to investigate the effectiveness of digital learning on learning Chinese as a second language (CSL) from the perspective of cognitive neuroscience, the present study integrated the interdisciplinary knowledge among digital learning, linguistics, and cognitive neuroscience by non-invasive neuroimaging technology measurement in addition to behavior assessment. The research evidences elaborate the learning effect as a result of the brain neural plasticity, in which was observed after the short-term and non-specific tonal perception training for CSL beginning learners. By using a MEG experiment of magnetic correspondent of mismatch negativity (MMNm) paradigm with within-subjects design, the present study investigated the learning effect of CSL beginning learner who enrolled in a short term digital learning program. In the experiment, the measurements of MMNm, with the contrast between large deviant T3/T1 and between small deviant T3/T2, were computed to index the patterns of processing lexical tone in the brain. Results of the MMNm data indicated that activation for large contrast T3/T1 elicited earlier and significantly larger amplitude than of the small deviant contrast T3/T2, which is in line with previous studies done on native Chinese speakers. More importantly, in the comparison of pre-test and post-test time course, the amplitude of MMNm showed a significant increase in the left hemisphere after learning. The evidenceindicated clearly a learning effect in the perception of linguistic features and a left lateralized neural network of processing Mandarin lexical tones as native-like pattern. Moreover, in the source analysis, the left lateralized patterns of prefrontal generator (i.e., insula) and generator of auditory cortex (i.e., Heschl's Gyrus) were observed after learning, which is also consistent with the native Mandarin speaker's response patterns. In other words, the present study provides neural evidence for a functional reorganization in the brain of CSL learners after a short-term and non-specific training program. The functional reorganization, in line with the duplex perception mechanism and functional –dependent lateralization, is reflected in transforming from predisposed acoustic-dependent right dominance for non-tonal language to linguistic functional-dependent left lateralization, as a tonal language native-like pattern. In sum, the present study provides an innovative implication of brain neural plasticity to bridge the changes of behavioral performance and neural mechanism of digital learning on second language.
In a digital age, bilingual learning is currently pervasive in globalization society and is inevitably facilitated by learning technology. In order to investigate the effectiveness of digital learning on learning Chinese as a second language (CSL) from the perspective of cognitive neuroscience, the present study integrated the interdisciplinary knowledge among digital learning, linguistics, and cognitive neuroscience by non-invasive neuroimaging technology measurement in addition to behavior assessment. The research evidences elaborate the learning effect as a result of the brain neural plasticity, in which was observed after the short-term and non-specific tonal perception training for CSL beginning learners. By using a MEG experiment of magnetic correspondent of mismatch negativity (MMNm) paradigm with within-subjects design, the present study investigated the learning effect of CSL beginning learner who enrolled in a short term digital learning program. In the experiment, the measurements of MMNm, with the contrast between large deviant T3/T1 and between small deviant T3/T2, were computed to index the patterns of processing lexical tone in the brain. Results of the MMNm data indicated that activation for large contrast T3/T1 elicited earlier and significantly larger amplitude than of the small deviant contrast T3/T2, which is in line with previous studies done on native Chinese speakers. More importantly, in the comparison of pre-test and post-test time course, the amplitude of MMNm showed a significant increase in the left hemisphere after learning. The evidenceindicated clearly a learning effect in the perception of linguistic features and a left lateralized neural network of processing Mandarin lexical tones as native-like pattern. Moreover, in the source analysis, the left lateralized patterns of prefrontal generator (i.e., insula) and generator of auditory cortex (i.e., Heschl's Gyrus) were observed after learning, which is also consistent with the native Mandarin speaker's response patterns. In other words, the present study provides neural evidence for a functional reorganization in the brain of CSL learners after a short-term and non-specific training program. The functional reorganization, in line with the duplex perception mechanism and functional –dependent lateralization, is reflected in transforming from predisposed acoustic-dependent right dominance for non-tonal language to linguistic functional-dependent left lateralization, as a tonal language native-like pattern. In sum, the present study provides an innovative implication of brain neural plasticity to bridge the changes of behavioral performance and neural mechanism of digital learning on second language.
Description
Keywords
大腦神經可塑性, 詞彙聲調, 不匹配負波腦磁反應, Brain Neural Plasticity, Lexical Tone, MMNm