数字推理的认知神经机制及其可塑性研究

数字推理是人脑一种重要的数学认知能力，然而到目前为止，对其认知神经机制的了解还很少。针对这一问题，本项目拟以健康青年大学生和早期轻度认知障碍（eMCI）患者为被试，结合直流经颅直流电磁刺激（tDCS）和功能磁共振fMRI从以下两个方面研究数字推理过程的脑机制。第一个方面是数字推理和数字计算的比较研究。检验“数字推理是不同于数字计算的一种认知过程”的假设：数字推理可能更多地激活时空间加工相关的脑区，而数字计算可能更多地激活言语加工相关的脑区。第二个方面是数字推理神经回路的可塑性研究。已有研究表明经颅随机噪声刺激(TRNS)可提高大脑工作记忆及数学运算能力，本研究将考察TRNS是否可以提高健康志愿者及eMCI患者的数字推理能力，以及这种可塑性的神经机制。本课题的研究意义在于：是探索人脑数学认知机制的重要组成；有望为认知障碍病人数字推理能力的康复治疗提供依据。

Numerical reasoning is an important ability of mathematical cognition of human brain, however, little is known about its cognitive neural mechanism. This proposal aims to reveal the neural correlates of numerical reasoning by applying the transcranial direct current stimulation (tDCS) and functional magnetic resonance imaging (fMRI) to both healthy undergraduates and early mild cognitive impairment (eMCI) patients, and contains the following two research aspects. 1) To examine the hypothesis that the cognitive processes of numerical reasoning is differentiated from numerical calculation, that is, the numerical reasoning was more like visuo-spatial representation processes, whereas the numerical calculation was more like verbal processes. 2) To examine the plasticity of the neural pathway of numerical reasoning. Previous study showed that transcranial random noise stimulation (TRNS) could improve the ability of working memory and mathematical operation. Thus, this proposal will explore whether the TRNS could improve the ability of numerical reasoning of both the healthy volunteer and eMCI patients. The significances of this proposal lies in: the important constitute of exploring the nature of human thinking, and providing the basis for rehabilitation therapy of the ability of numerical reasoning of cognitive impairment patients.