健康与遗传心理学研究室知识库

序列运动脑结构基础的研究对于理解随意运动的神经机制具有重要意义。有关研究尽管很多，但尚有争议之处。事件相关功能磁共振成像作为一种基于单个刺激的无损伤脑功能探测手段，为研究序列运动的脑机制提供了有用的工具。
方法:本实验应用事件相关功能磁共振成像技术观察了巧名右利手正常人运动过程中大脑皮层的活动情况。实验任务是即时和延时条件下的简单与序列手指运动。经过反卷积和多重回归分析，探测出激活区，然后基于感兴趣区域进行了定量分析，包括激活体积、激活强度和时间反应曲线分析。
结果:简单运动激活辅助运动区和对侧感觉运动区，而60%的被试在运动前区与顶叶后部也有激活。序列运动不但激活了简单任务激活的所有脑区，并且激活体积比简单运动大。在激活强度上，对侧感觉运动区、对侧运动前区和后顶叶皮层在复杂运动时强于简单运动;而在对侧运动前区和对侧后顶叶皮层的延时一复杂运动引起的信号变化率强于即时复杂运动。
结论:各脑区基本上都参与四种运动任务。辅助运动区和对侧初级运动区分别参与运动准备和执行，是运动控制必不可少的。运动前区和后顶叶皮层在需要工作记忆和时空组织等高级功能的运动任务时起重要作用。以上各脑区在运动过程中既分工又合作，构成一个相对完整的皮层运动控制系统。

    Although neural substrates for sequential  movements  have  been  intensively
investigated, a series of issues remain contraversial. Event-related functional magnetic resonance imaging, a single-trial based non-invasive brain imaging technique, has provided an effective tool for exploring the neural mechanisms underlying simple and sequential movements.
    Methods: Event-related fMRI was used to investigate the activation of cerebral cortex during movements in 15 normal right-handed volunteers. The movement task included delayed (moving during cue presentation) and non-delayed (not moving until the end of cue presentation) "simple" (repetitively moving index finger) and "sequential" (sequentially moving all fingers according to the cue singal) movements. Multiple linear regression and deconvolution procedure was used to}detect the active ,brain region. Quantitative analysis was further implemented for comparison of the activation volume and intensity in each ROI between different movement tasks.
    Results:  While the supplementary  motor area (SMA) and contralateral sensorimotor cortex (SMC) were activated in all subjects during simple movements,only 60% subjects showed activation in bilateral premotor cortex (PMC), and bilateral posterior parietal cortex (PPC) during } sequential movements. All activated regions during simple movements were also activated during sequential movements, and the activated volume is larger than that of simple movements. The signal intensity in the contralateral SMC, bilateral PMC and PPC during sequential finger movement was significantly stronger than that during simple finger movements; the signal change  in  ipsilateral  PMC  and  contralateral  PPC  during  delayed  sequential movements was stronger than that during non-delayed sequential movements.
    Conclusion: Almost all studied brain areas are enganged during all four movement tasks in the present study. SMA and contralateral Ml play a critical role in motor control, involved in motor preparation and exectution respectively. When in tasks with higher spatio-temporal coordination and working memory demanding, PMC and PPC become more active. The present study revealed a distributed cortical network, areas within this network play complemental roles for coordination and execution of movements.