情绪性语境调控下词汇学习的认知神经机制

Word learning skills are important for individuals in modern society. Numerous studies have investigated neuro-cognitive mechanism of word learning and suggest that word learning involves changes in neural activity within the frontal and temporal cortices during learning. With learning, this activation result in a functional reorganization of these brain regions. However, emotion as an influencing factor on word learning and the resulting neuro-cognitive mechanisms has been neglected in previous studies. By using a novel online and offline context-based word learning paradigm combined with state-of-the-art techniques, such as event related potentials (ERPs) and functional magnetic resonace imaging (fMRI), the present project aims to systematically investigate the mechanisms of word learning under emotional context modulation at both cognitive and neural level. First, we will examine how emotional context impacts word learning performance behaviorally as well as related brain activity (ERPs and fMRI) in three offline context-based word learning experiments. Two online fMRI context-based word learning experiments will follow in order to further investigate how the neural effects of emotional modulation are developed in the process of word learning. The results of the present project will not only shed light on the interaction between emotion and cognition, but also contribute significantly to the theory of brain plasticity in word learning with regards to its relationship with emotion. The present project will also have potential to generate useful practical implications in education such as instructions for reading.

词汇学习对于个体提高语言能力、掌握科学文化知识具有重要意义，近年来引起了研究者的关注。已有研究表明词汇学习经验可以导致额颞皮层网络的功能可塑性变化，而词汇学习过程本身则卷入了额颞多个脑区的动态活动。然而目前尚无研究较为系统地考察情绪因素在词汇学习中的作用，因此情绪调控下词汇学习的认知神经机制是怎样的仍不清楚。本项目拟采用离线和实时在线的基于语境的词汇学习范式，结合行为、ERP和fMRI等多种认知神经科学研究方法，首先在行为与脑水平上考察情绪性语境对词汇学习有何种影响，揭示情绪性语境对词汇学习的行为效果及相关脑可塑性变化的调节效应；然后再进一步考察情绪性语境对词汇动态学习过程的影响，揭示情绪性语境对词汇学习调控效应的产生机制。本项目研究对于完善情绪与认知的交互理论，深化理解情绪与脑功能发展的关系具有重要的理论意义，同时也为促进阅读教学、开展基于脑的教育提供一定的借鉴。

词汇学习对于个体提高语言能力、掌握科学文化知识具有重要意义，然而目前尚无研究较为系统地考察情绪因素在词汇学习中的作用。本项目采用离线和实时在线的基于语境的词汇学习范式，结合行为、ERP和fMRI等多种认知神经科学研究方法，从三个方面开展了研究：1）考察了语境情绪对词汇学习引起脑可塑性变化的调节效应。结果发现，语境情绪显著影响词汇学习效果，并对学习效应相关的右侧角回，双侧脑岛和前扣带回的功能可塑性变化具有显著影响。2）探讨了语境内容对词汇学习过程的影响。发现语境情绪对词汇学习产生的重要影响，并且进一步揭示词汇意义编码过程中P2和LPC成分受到情绪调节，这表明情绪在词汇编码的早期及词义整合的晚期阶段均产生的影响。3）探讨了情绪韵律对词汇学习过程的动态调节机制。结果发现：愤怒韵律对词汇学习有显著的消极作用，相比具体词，情绪韵律更影响被试对抽象词的学习；情绪韵律对词汇学习的调节作用是在学习过程中对词汇语义提取及晚期语义整合产生影响而形成的。基于上述研究发现，我们揭示了情绪性语境对词汇学习的行为效果及相关脑可塑性变化的调节效应；也进一步探讨了情绪性语境对词汇动态学习过程的影响，揭示情绪性语境对词汇学习调控效应的产生机制。