The interplay between attention, alertness and motor planning is crucial for our manual interactions. To investigate the neural bases of this interaction, and challenging the views that attention cannot be disentangled from motor planning, we instructed human volunteers of both sexes to plan and execute reaching movements while attending to the target, while attending elsewhere, or without constraining attention. We recorded reaction times to reach initiation and pupil diameter and interfered with the functions of the medial posterior parietal cortex (mPPC) with online repetitive transcranial magnetic stimulation to test the causal role of this cortical region in the interplay between spatial attention and reaching. We found that mPPC plays a key role in the spatial association of reach planning and covert attention. Moreover, we have found that alertness, measured by pupil size, is a good predictor of the promptness of reach initiation only if we plan a reach to attended targets, and mPPC is causally involved in this coupling. Different from previous understanding, we suggest that mPPC is neither involved in reach planning per se, nor in sustained covert attention in absence of a reach plan, but it is specifically involved in attention functional to reaching.Significance Statement Attention is required to perform dexterous arm movements. In this work we show the neural bases of the interplay between attention and reaching preparation, with the aim to provide information useful to address effective rehabilitation strategies to treat functional deficits observed in attention-related diseases. We discuss how brain areas are involved in orchestrating attention and reaching by signaling the alignment of their spatial coordinates. Moreover, we found that pupil size changes during reach preparation are related to reach initiation, suggesting a coordination between vigilance and reach promptness when preparing a reach to attended targets.

中文翻译：

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内侧后顶叶皮层在协调注意力和到达中的作用。


注意力、警觉性和运动规划之间的相互作用对于我们的手动交互至关重要。为了研究这种互动的神经基础，并挑战注意力不能与运动规划分开的观点，我们指示男女人类志愿者在关注目标的同时，在其他地方参加，或者在不限制注意力的情况下计划和执行到达动作。我们记录了达到起始和瞳孔直径的反应时间，并通过在线重复经颅磁刺激干扰内侧后顶叶皮层 （mPPC） 的功能，以测试该皮质区域在空间注意力和到达之间相互作用中的因果作用。我们发现 mPPC 在覆盖率规划和隐蔽注意力的空间关联中起关键作用。此外，我们发现，只有当我们计划到达有人值守的目标时，以瞳孔大小衡量的警觉性才能很好地预测到达开始的迅速性，而 mPPC 与这种耦合有因果关系。与以前的理解不同，我们认为 mPPC 本身既不参与覆盖率计划本身，也不涉及在没有覆盖率计划的情况下持续的隐蔽关注，但它专门涉及覆盖率的注意力功能。意义陈述 需要注意进行灵巧的手臂动作。在这项工作中，我们展示了注意力和到达准备之间相互作用的神经基础，旨在提供有用的信息，以解决有效的康复策略，以治疗在注意力相关疾病中观察到的功能缺陷。我们讨论了大脑区域如何通过发出空间坐标对齐的信号来参与编排注意力和到达。 此外，我们发现 reach 准备期间瞳孔大小的变化与 reach 启动有关，这表明在准备到达有人值守的目标时，警惕性和 reach 及时性之间存在协调。