Mattay V S, Callicott J H, Bertolino A, Santha A K, Van Horn J D, Tallent K A, Frank J A, Weinberger D R
Clinical Brain Disorders Branch, NIMH, NIH, Bethesda, MD 20892, USA.
Psychiatry Res. 1998 Jul 15;83(1):7-22. doi: 10.1016/s0925-4927(98)00023-7.
The aim of this study was to explore whether recruitment of the ipsilateral motor cortex during non-dominant motor movement reflects left hemispheric control of motor function or simply the greater complexity or unfamiliarity of the motor task. BOLD fMRI was performed in normal right-handers during two motor tasks: (1) sequential finger movements (SM task) with the right or left hand; and (2) random finger movements (RM task) with the right hand. In all subjects, activation was predominantly in the contralateral motor areas (primary sensorimotor, lateral premotor, parietal and supplementary motor regions) and ipsilateral cerebellum. While the ipsilateral motor areas were also activated, single subject analysis revealed these areas to be more extensive and to be seen in more subjects during the non-dominant hand SM task and dominant hand RM task than during the more familiar dominant hand SM task. Similarly, group analysis also revealed ipsilateral activation in the primary sensorimotor and lateral premotor areas, but only during the non-dominant SM task and the dominant hand RM task. Non-dominant hand movements, perhaps because they are less 'automatic', appear to require more cortical activity similar to complex tasks with the dominant hand, and result in greater recruitment of ipsilateral cortical motor areas and striatum. The study also illustrates how potentially meaningful subtleties seen on individual maps may be obscured with group averaging approaches.
本研究的目的是探讨在非优势手运动过程中同侧运动皮层的激活是反映了左半球对运动功能的控制，还是仅仅反映了运动任务的更大复杂性或不熟悉程度。在正常右利手个体执行两项运动任务期间进行了血氧水平依赖性功能磁共振成像（BOLD fMRI）：（1）用右手或左手进行顺序手指运动（SM任务）；以及（2）用右手进行随机手指运动（RM任务）。在所有受试者中，激活主要出现在对侧运动区域（初级感觉运动区、外侧运动前区、顶叶和辅助运动区）以及同侧小脑。虽然同侧运动区域也被激活，但单受试者分析显示，与更熟悉的优势手SM任务相比，这些区域在非优势手SM任务和优势手RM任务期间更广泛，且在更多受试者中可见。同样，组分析也显示在初级感觉运动区和外侧运动前区存在同侧激活，但仅在非优势手SM任务和优势手RM任务期间出现。非优势手运动可能由于其较少“自动性”，似乎需要更多类似于优势手复杂任务的皮层活动，并导致同侧皮层运动区和纹状体的更大激活。该研究还说明了个体图谱上可见的潜在有意义的细微差异可能如何被组平均方法所掩盖。
