Slobounov Semyon, Wu Tao, Hallett Mark
Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
Motor Control. 2006 Jan;10(1):69-89. doi: 10.1123/mcj.10.1.69.
Human upright posture is a product of a complex dynamic system that relies on integration of input from multimodal sensory sources. Extensive research has explored the role of visual, vestibular, and somatosensory systems in the control of upright posture. However, the role of higher cognitive function in a participant's assessment of postural stability has been less studied. In previous research, we showed specific neural activation patterns in EEG associated with recognition of unstable postures in young healthy participants. Similar EEG patterns have been recently observed in regulation of posture equilibrium in dynamic stances. This article evaluates participants' postural stability in dynamic stances and neural activation patterns underlying visual recognition of unstable postures using event-related functional MRI (fMRI). Our results show that the "stable" participants were successful in recognition of unstable postures of a computer-animated body model and experienced egocentric motion. Successful recognition of unstable postures in these participants induces activation of distinct areas of the brain including bilateral parietal cortex, anterior cingulate cortex, and bilateral cerebellum. In addition, significant activation is observed in basal ganglia (caudate nucleus and putamen) but only during perception of animated postures. Our findings suggest the existence of modality-specific distributed activation of brain areas responsible for detection of postural instability.
人类直立姿势是一个复杂动态系统的产物，该系统依赖于多模态感觉源输入的整合。大量研究探讨了视觉、前庭和体感系统在控制直立姿势中的作用。然而，高级认知功能在参与者评估姿势稳定性中的作用研究较少。在先前的研究中，我们在脑电图中显示了与年轻健康参与者识别不稳定姿势相关的特定神经激活模式。最近在动态姿势下调节姿势平衡时也观察到了类似的脑电图模式。本文使用事件相关功能磁共振成像（fMRI）评估参与者在动态姿势下的姿势稳定性以及视觉识别不稳定姿势背后的神经激活模式。我们的结果表明，“稳定”的参与者能够成功识别计算机动画人体模型的不稳定姿势并体验到自我中心运动。这些参与者成功识别不稳定姿势会诱发大脑不同区域的激活，包括双侧顶叶皮层、前扣带回皮层和双侧小脑。此外，在基底神经节（尾状核和壳核）中观察到显著激活，但仅在感知动画姿势时出现。我们的研究结果表明，存在负责检测姿势不稳定的脑区的模态特异性分布式激活。
