从发展认知神经科学角度研究文字加工系统的形成机制

快速和准确的书面文字阅读依赖于人脑高度专门化的文字加工系统。揭示该系统的形成机制对阐明文字习得的神经基础及促进语文教育和矫正阅读障碍至关重要。要阐明文字加工系统的形成机制，亟需解决两个递进的关键科学问题。第一个问题是在文字加工系统形成过程中神经活动的变化规律是什么？对此，主要有特征检测和预期编码两种理论，但迄今两种理论均缺乏结论性的证据支持。第二个问题是，在深层神经机制上，文字加工系统形成过程中神经活动发生了何种方式的变化，是幅度增加、同步性增强抑或是两者兼有？本项目拟采用横断与纵向相结合的研究设计，系统地刻画文字加工专门化的脑电生理标记（即N170成分）在儿童自然文字习得过程中的发展轨迹，检验上述两种理论；进而采用能有效测量神经活动的幅度和同步性的单试次分析技术揭示文字加工专门化形成的深层神经机制。本项目在研究思路方面有重要突破，研究成果将为深入认识文字加工系统的形成机制提供关键证据。

Efficient reading relies on a specialized neural system for visual word processing. Revealing how this specialized neural system emerges and develops will greatly advance our understanding of the neural mechanisms underlying reading acquisition, and more importantly, has profound practical implications on literacy education and reading difficulty intervention. Recent development in the field highlights two critical yet unresolved theoretical questions on the specialized neural system for visual word processing. First, what is the neural mechanism that drives the emergence and development of the specialized system for visual word processing? Researchers have suggested two possible mechanisms, i.e., feature detection and predictive coding, but empirical work in the field has yet produced any conclusive evidence for or against either theory. Second, what is the deeper neural mechanism underlying the emergence and development of the specialized neural system? Is it an increase in the strength or the synchronization of neural activity, or an increase in both? By combining a cross-sectional and a longitudinal design, the present research project will take a developmental approach to systematically characterize the developmental trajectory of an electrophysiological marker for the specialized neural system (i.e., N170 component). The present project will verify the feature detection and predictive coding theories, and with a single-trial analysis technique, will reveal the deeper neural mechanism underlying the emergence and development of the specialized visual word processing system. With a developmental research approach and an effective electrophysiological data analysis technique, the present project is expected to produce insightful and conclusive empirical results that will unveil the mechanisms underlying the emergence and development of the visual word system.