应用动态因果模型研究阅读神经网络背、腹侧通路的协作机制

在神经网络的最新取向下, 探讨阅读脑机制中背侧和腹侧通路的协作机制, 是解决语言认知神经科学多个理论问题共同面临的焦点。本项目拟通过两个脑功能成像实验, 建构汉字阅读的动态因果模型, 系统地考察汉字阅读的神经网络, 以及阅读网络中背、腹侧通路的协作机制。实验一利用快速适应实验范式的优点, 识别和考察汉字阅读涉及的认知成分所对应的功能脑区, 以及脑区联结形成的神经回路, 并建构汉字阅读的动态因果模型; 实验二进一步考察在刺激属性(语音和语义信息)和任务要求下阅读脑区的动态激活及相互作用。通过不同任务下的模型对比, 重点探讨阅读网络的脑区联结模式变化, 尤其是背、腹侧通路受刺激和任务影响时的协作机制。研究结果将为揭示阅读的神经生理模型、解决语言特异性脑区激活的争论等理论问题提供直接的证据, 还能为语言教学、阅读障碍矫治、以及临床应用提供理论基础与指导。

Adapting Dynamic Causal Modeling to Investigate the Cooperation between the Ventral and Dorsal Routes of Reading Neural Network

Exploring the neuroanatomical model of visual word reading is one of the essential theoretical issue in cognitive neuroscience of language. Converging findings reveal that the dorsal and ventral routes are involved in reading neural network, but how they overlap and interact remains unclear and controversial. Using the Dynamic Causal Modeling (DCM) approach, the current project proposes two fMRI experiments to investigate the ventral and dorsal routes and their cooperation in Chinese character reading. Experiment 1, taking advantage of fMRI rapid adaption techniques, is designed to identify brain regions for cognitive components of reading processing. Both the GLM and DCM analysis are conducted to investigate the neural network, as well as two routes (the dorsal and ventral routes) for Chinese character reading. Experiment 2 further manipulates the stimulus properties (semantic and phonological cues) and task demands (symbolic, semantic, phonological detection task), to test the brain activation and connectivity among regions of reading neural network. By further comparing the DCMs including the same brain structures across three tasks, the different connectivity patterns will reveal how our brain regions in the same reading network interact for different types of stimuli or different processing demands. The combined results will test the idea of universal brain neural basis for cross languages reading. Also, it will provide theoretical guidance for empirical studies and applications, such as language teaching, treatment of reading disorders and clinical diagnoses.