Intentional motor action is typically characterized by the decision about the timing, and the selection of the action variant, known as the “what” component. We compared free action selection with instructed action, where the movement type was externally cued, in order to investigate the action selection and action representation in a Libet’s task. Temporal and spatial locus of these processes was examined using the combination of high-density electroencephalography, topographic analysis of variance, and source reconstruction. Instructed action, engaging representation of the response movement, was associated with distinct negativity at the parietal and centro-parietal channels starting around 750 ms before the movement, which has a source particularly in the bilateral inferior parietal lobule. This suggests that in delayed-action tasks, the process of action representation in the inferior parietal lobule may play an important part in the larger parieto-frontal activity responsible for movement selection.

有意的运动动作的典型特征是关于时间的决定和动作变体的选择，称为“什么”组件。我们将自由动作选择与指令动作进行了比较，其中动作类型是外部提示的，以研究 Libet 任务中的动作选择和动作表示。使用高密度脑电图、方差地形分析和源重建的组合检查这些过程的时空轨迹。指示性动作，参与反应运动的表现，与运动前 750 ms 左右开始的顶叶和中央顶叶通道的明显阴性有关，其来源特别是在双侧顶下小叶。这表明在延迟动作任务中，