Evidence for context sensitivity of grasp representations in human parietal and premotor cortices.
Evidence for context sensitivity of grasp representations in human parietal and premotor cortices.
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人类顶叶和前运动皮层中掌握表征的上下文敏感性的证据。
DOI：
10.1152/jn.00796.2010
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发表时间：
2011
影响因子：
2.5
通讯作者：
Frey,ScottH
中科院分区：
文献类型：
--
作者：
Marangon,Mattia;Jacobs,Stephane;Frey,ScottH
猕猴嘴侧顶下小叶（PF/PFG）和前顶内区（AIP）神经元的抓握相关反应受任务情境的调制。事件相关功能MRI被用来确定这是否是真的，在假定的同源的人类皮质，喙顶下小叶（rIPL）和前顶内沟（aIPS）。15名健康的右撇子成年人被要求前瞻性地选择最舒适的方式来抓住一个水平方向的手柄使用提示的手（左或右）。在“无旋转”条件下，任务只是抓住手柄，而在“旋转”条件下，目标是计划抓住并旋转手柄到垂直方向，提示端（内侧或外侧）指向下方。在这两种情况下，参与者保持不动，并通过踩下脚踏板来表明他们的抓握偏好。在公开的把握，参与者的抓握偏好显着影响的预期与手柄旋转的需求。在旋转和无旋转条件下，aIPS和rIPL内的活性双侧增加。重要的是，这些反应在旋转与无旋转条件下显着更大。在前辅助运动区、尾侧顶内沟/上级顶叶小叶、双侧背侧和左腹侧运动前皮质中检测到类似的背景效应。在rIPL和aIPS的把握表示是敏感的预测任务的需求，并在上下文敏感的抓地力选择中发挥作用。此外，研究结果提供了额外的证据表明，在抓的感觉运动控制领域也有助于前馈规划。
Grasp-related responses in neurons of the macaque rostral inferior parietal lobule [PF/PFG and the anterior intraparietal area (AIP)] are modulated by task context. Event-related functional MRI was used to determine whether this is true in putative homologs of the human cortex, the rostral inferior parietal lobule (rIPL) and the anterior intraparietal sulcus (aIPS). Fifteen healthy, right-handed adults were required to select prospectively the most comfortable way to grasp a horizontally oriented handle using the cued hand (left or right). In the “no-rotation” condition, the task was simply to grasp the handle, whereas in the “rotation” condition, the goal was to plan to grasp and rotate it into a vertical orientation with the cued end (medial or lateral) pointing downward. In both conditions, participants remained still and indicated their grip preferences by pressing foot pedals. As in overt grasping, participants' grip preferences were significantly influenced by anticipation of the demands associated with handle rotation. Activity within the aIPS and rIPL increased bilaterally in both the rotation and no-rotation conditions. Importantly, these responses were significantly greater in the rotation vs. no-rotation condition. Similar context effects were detected in the presupplementary motor area, caudal intraparietal sulcus/superior parietal lobule, and bilateral dorsal and left ventral premotor cortices. Grasp representations within the rIPL and aIPS are sensitive to predicted task demands and play a role in context-sensitive grip selection. Moreover, the findings provide additional evidence that areas involved in the sensorimotor control of grasp also contribute to feedforward planning.