尽管人类的操作能力在灵长类动物中是独特的，但比较观察表明，这些认知运动技能可能来自对系统发展更早且具有类属关系的构建模块的利用和适应，即支持抓握和操作的顶叶-额叶网状结构。在这个框架下，研究抓握和抓握-操作在顶叶-额叶回路中的重叠和分歧程度，有助于理解人类认知如何塑造手部动作。迄今为止，尚未通过组合损伤定位和直接电生理方法进行神经外科患者的研究。为了达到这个目的，根据纳入标准选择了79例右撇子左脑肿瘤患者，这些患者适合醒觉神经外科手术。首先，在术后早期阶段进行损伤定位，以确定与操作能力（模仿无意义和有意义的非传统性手势）和视觉引导抓握（抓取）能力受损相关的区域。然后，损伤结果与术中确定的皮层和白质区域进行解剖匹配，其直接电刺激影响手操作任务。损伤定位分析显示，早期术后阶段发生的抓握和操作能力受损与特定的顶叶部分相关。包括顶极顶叶和枕叶在内的背偏正中央顶叶切除影响抓握表现，而涉及鞍上、下顶叶区域的切除影响操作能力（协变簇，5000次置换，CFWER p <0.05）。鞍上前额顶沟的背侧皮层不仅与抓握，还与操作有关（非协变簇的重叠）。在操作结果中，涉及下顶叶区域的切除主要影响有意义手势的模仿，而涉及顶叶区域的切除影响无意义和有意义手势的模仿。同时，在手操作任务期间，对鞍上前额顶沟和相邻下顶叶的脑内电刺激引起了不同的运动障碍，即停止和笨拙模式。当综合损伤定位和术中刺激结果时，可以发现模仿操作手势首先取决于背-腹流中顶叶区域的完整性。在这些区域中，鞍上前额顶沟和下顶叶区域在操作和感觉运动过程中控制操作中起着不同的作用。由于其视觉运动特征，鞍上前额顶沟可作为猴子AIP的人类类似物，实现所观察手势的视觉运动转换（直接通路）。此外，它与相邻的更近进化的下顶叶区域的功能互作可能有助于将语义-概念知识（间接通路）整合到感觉运动工作流程中，促进手部动作的认知升级。© 作者（们）2023年。由牛津大学出版社代表Brain的保证人发表。

Despite human's praxis abilities are unique among primates, comparative observations suggest that these cognitive motor skills could have emerged from exploitation and adaptation of phylogenetically older building blocks, namely the parieto-frontal networks sub-serving prehension and manipulation. Within this framework, investigating to which extent praxis and prehension-manipulation overlap and diverge within parieto-frontal circuits could help in understanding how human cognition shapes hand actions. This issue has never been investigated by combining lesion mapping and direct electrophysiological approaches in neurosurgical patients. To this purpose, seventy-nine right-handed left-brain tumor patients candidate for awake neurosurgery were selected based on inclusion criteria. First, a lesion mapping was performed in the early post-operative phase to localize the regions associated to an impairment in praxis (imitation of meaningless and meaningful intransitive gestures) and visuo-guided prehension (reaching-to-grasping) abilities. Then, lesion results were anatomically matched with intraoperatively identified cortical and white matter regions, whose direct electrical stimulation impaired hand-manipulation task. The lesion mapping analysis showed that prehension and praxis impairments occurring in early post-operative phase were associated to specific parietal sectors. Dorso-mesial parietal resections, including the superior parietal lobe and precuneus, affected prehension performance, while resections involving rostral intraparietal and inferior parietal areas affected praxis abilities (covariate clusters, 5000 permutations, CFWER p < 0.05). The dorsal bank of the rostral intraparietal sulcus was associated to both prehension and praxis (overlap of non-covariate clusters). Within praxis results, while resection involving inferior parietal areas affected mainly the imitation of meaningful gestures, resection involving intraparietal areas affected both meaningless and meaningful gesture imitation. In parallel, the intraoperative electrical stimulation of the rostral intraparietal and the adjacent inferior parietal lobe with their surrounding white matter during hand-manipulation task evoked different motor impairments, i.e. the arrest and clumsy patterns respectively. When integrating lesion mapping and intraoperative stimulation results, it emerges that imitation of praxis gestures first depends on the integrity of parietal areas within the dorso-ventral stream. Among these areas, the rostral intraparietal and the inferior parietal area play distinct roles in praxis and sensorimotor process controlling manipulation. Due to its visuo-motor "attitude", the rostral intraparietal sulcus, putative human homologue of monkey AIP, might enable the visuo-motor conversion of the observed gesture (direct pathway). Moreover, its functional interaction with the adjacent, phylogenetic more recent, inferior parietal areas might contribute to integrate the semantic-conceptual knowledge (indirect pathway) within the sensorimotor workflow, contributing to the cognitive up-grade of hand-actions.© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.