第二语言学习与脑可塑性

Second language learning and brain plasticity

脑可塑性指人脑会因为环境刺激、认知需求和行为经验而产生功能或结构改变。近10年来的单双语者对比和语言训练研究结果表明,不论儿童、青年或老年人,第二语言学习和使用都能改变其脑运行模式并带来相应结构变化,包括灰质(GM)体积和白质(WM)密度增加,且长期持续的双语经验还能形成认知优势,帮助抵制由老化导致的负面认知影响。基于脑可塑性概念及其研究证据,从双语经验与语言训练两方面,对比分析了长期和短期第二语言学习引起脑功能或结构变化及其内在机制,并对未来相关研究进行了展望。

Brain plasticity refers to any functional change or structural reconfiguration of the brain triggered by environmental stimulation,cognitive demands and behavior experience.About a decade of research with bilingualism and language training shows that,whether we are the young or the old,long-term or short-term L2 learning can influence our brain’s functional pattern as well as its corresponding anatomical changes.Included are the increased volume of gray matter(GM)and density of white matter(WM)as well as the reorganization of neural networks.Long-time and continuous L2 learning will promote functional executive control and its neural underpinnings,which may protect neural reserve against aging.Based on brain plasticity,cross-sectional and longitudinal studies involved are compared and the mechanism of how both functional and structural changes occur in the brain as a function of L2 learning is discussed.Additionally,some suggestions are presented for future exploration.