中国科学院心理研究所机构知识库

本研究利用功能磁共振成像技术分别从功能组织和功能联结两个角度对大脑皮层运动系统进行了较为系统的探讨。实验一、二、三分别采用组块和事件相关两种实验设计模式，从定量的角度对不同运动成分在大脑皮层运动系统中的空间分布规律进行了层层深入的研究和探讨；实验四则采用新近发展起来的低频波分析技术，研究了静止和运动两种状态下大脑皮层运动系统的功能联结模式。 本研究的主要结果和结论如下： 1. 大脑皮层运动系统的各个脑区都参与简单和复杂运动，尽管次级运动区在复杂运动过程中的激活强度弱于初级运动区（M1）。除M1外，各个脑区都可见到两种运动差异的梯度分布。2. 各个脑区在实际运动和想象运动是均被显著激活，而且除M1外，这些脑区也呈现类似的梯度分布。这一结果表明，大脑皮层运动系统功能组织与运动执行和运动准备有关。3. 利用事件相关fMRI和延迟序列运动模型，我们进一步发现，这种运动准备和运动执行的梯度分布是线性的和连续的。4. 大脑皮层运动系统由两个子系统组成。其中一个系统由功能较为低级的双侧M1组成，而另一个由功能较为高级的双侧SMA、PMC和PPC等脑区组成。
5. 运动状态下大脑皮层运动系统层次性联结趋于融合，这反映了运动状态下两个子系统之间联结强度的增强。
6. 反卷积、多重回归分析和一般线性检验相结合的方法有利于定量揭示大脑功能系统的空间分布规律。“双核心”的低频波分析方法是研究大脑功能系统不同层次联结和联结变化的有效方法。

The present study aimed to systematically characterize functional organization and functional connectivity of the motor system in the cerebral cortex with functional magnetic resonance imaging. In the first three experiments, we investigated brain activation in cerebral cortex during simple and complex movements, real and imagined movements, and delayed sequential movements. In experiment 4, using newly-developed analysis technology for low-frequency spontaneous fluctuations, we investigated functional connective in resting and continuing movements respectively.
Main results and conclusions are summarized as follows:1) All regions in the cerebral motor system were engaged in simple and complex movements, although activation in the secondary motor areas was not as strong as that in the primary motor cortex. A gradient distribution was found in most regions except for M1.
2) All regions were activated during real and imagined movement tasks and a similar gradient distribution was found in most regions except for M1. This finding suggests that functional organization in the cerebral motor system is associated with motor preparation and execution.
3) Using event-related fMRI and a delayed sequential movement task, we further revealed that the gradient distribution of preparation- and execution-related activity was organized continually and in a linear fashion.
4） “Double-seed” analysis of LFF revealed two subsystems in the cerebral motor systems. While one subsystem is mainly constituted by lower-level functional regions such as bilateral M1, the other includes relatively higher-level functional regions such as bilateral pre-SMA, PPC, and PMC.
5) Functional connectivity between two subsystems was strengthen during continuing movements, suggesting that movements require cooperation of two subsystems.
The combination of deconvolution, multiple linear regression, and general linear test is feasible for analysis of functional organization of a given brain system. “Double-seed” analysis of LFF is an effective method to characterize functional connectivity and its modulation in multi-level brain systems.