Department of Psychology, University of California, Berkeley, Berkeley, United States.
UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, United States.
Elife. 2022 Mar 1;11:e69977. doi: 10.7554/eLife.69977.
Neurophysiological studies in humans and nonhuman primates have revealed movement representations in both the contralateral and ipsilateral hemispheres. Inspired by clinical observations, we ask if this bilateral representation differs for the left and right hemispheres. Electrocorticography was recorded in human participants during an instructed-delay reaching task, with movements produced with either the contralateral or ipsilateral arm. Using a cross-validated kinematic encoding model, we found stronger bilateral encoding in the left hemisphere, an effect that was present during preparation and was amplified during execution. Consistent with this asymmetry, we also observed better across-arm generalization in the left hemisphere, indicating similar neural representations for right and left arm movements. Notably, these left hemisphere electrodes were centered over premotor and parietal regions. The more extensive bilateral encoding in the left hemisphere adds a new perspective to the pervasive neuropsychological finding that the left hemisphere plays a dominant role in praxis.
人类和非人类灵长类动物的神经生理学研究表明，对侧和同侧半球都存在运动表现。受临床观察的启发，我们想知道这种双侧表现是否因左右半球而有所不同。在一项指令延迟伸手任务中，对人类参与者进行了脑电图记录，手臂的运动来自对侧或同侧。使用交叉验证的运动学编码模型，我们发现左侧半球的双侧编码更强，这种效应在准备阶段存在，并在执行阶段放大。与这种不对称性一致，我们还观察到左侧半球的跨臂泛化更好，这表明左右手臂运动的神经表现相似。值得注意的是，这些左侧半球的电极集中在前运动和顶叶区域。左侧半球更广泛的双侧编码为普遍的神经心理学发现增加了一个新视角，即左半球在实践中起着主导作用。
