Ipsilateral motor cortex activity during unimanual hand movements relates to task complexity
Ipsilateral motor cortex activity during unimanual hand movements relates to task complexity
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DOI：
10.1152/jn.00720.2004
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发表时间：
2005-03-01
影响因子：
2.5
通讯作者：
Ivry, RB
中科院分区：
文献类型：
--
作者：
Verstynen, T;Diedrichsen, J;Ivry, RB
功能成像研究显示，在产生顺序的单手指运动时，同侧运动区被招募。这一现象在左手运动时在左半球比在右手运动时在右半球更为突出。在这里，我们研究这种偏侧化模式是与单手动作的顺序结构特别相关，还是推广到其他复杂的动作。使用事件相关功能磁共振成像，我们测量了三种类型的单手动作中运动皮质的激活变化：多个手指重复一系列动作，由三个同时按键组成的重复的“和弦”，以及单一手指的简单重复敲击动作。在顺序运动和弦运动中，观察到同侧的强烈激活，尤其是在左手运动时，左半球的激活尤其明显。这种模式在右撇子和较小程度上都很明显。左撇子。在敲击状态下，同侧激活不那么明显。与对侧运动中观察到的相比，同侧激活的位置发生了侧向、腹向和前移，激活的时间进程暗示着在运动的执行中发挥作用，而不是在运动计划中。一项对照实验表明，左侧运动皮质中强烈的同侧活动是复杂运动所特有的，与所需肌肉的数量无关。这些发现表明，无论任务的顺序性质如何，左脑在执行复杂动作中起着突出的作用。
Functional imaging studies have revealed recruitment of ipsilateral motor areas during the production of sequential unimanual finger movements. This phenomenon is more prominent in the left hemisphere during left-hand movements than in the right hemisphere during right-hand movements. Here we investigate whether this lateralization pattern is related specifically to the sequential structure of the unimanual action or generalizes to other complex movements. Using event-related fMRI, we measured activation changes in the motor cortex during three types of unimanual movements: repetitions of a sequence of movements with multiple fingers, repetitive "chords" composed of three simultaneous key presses, and simple repetitive tapping movements with a single finger. During sequence and chord movements, strong ipsilateral activation was observed and was especially pronounced in the left hemisphere during left-hand movements. This pattern was evident for both right-handed and, to a lesser degree. left-handed individuals. Ipsilateral activation was less pronounced in the tapping condition. The site of ipsilateral activation was shifted laterally, ventrally, and anteriorly with respect to that observed during contralateral movements and the time course of activation implied a role in the execution rather than planning of the movement. A control experiment revealed that strong ipsilateral activity in left motor cortex is specific to complex movements and does not depend on the number of required muscles. These findings indicate a prominent role of left hemisphere in the execution of complex movements independent of the sequential nature of the task.