Reach Trajectories Characterize Tactile Localization for Sensorimotor Decision Making
Reach Trajectories Characterize Tactile Localization for Sensorimotor Decision Making
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DOI：
10.1523/jneurosci.1873-14.2015
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发表时间：
2015-10-07
影响因子：
5.3
通讯作者：
Heed, Tobias
中科院分区：
文献类型：
--
作者：
Brandes, Janina;Heed, Tobias
用于运动规划的空间目标信息似乎被编码在以凝视为中心的参考系中。然而，在触摸中，位置最初是参考皮肤进行编码的。因此，触觉空间位置必须通过整合皮肤位置和姿势来得出。有人认为，当肢体放置在相反的半空间时，例如通过肢体交叉，这种记录会受到损害。在这里，人类参与者在感觉运动决策任务中接触位于非交叉脚和交叉脚的视觉和触觉目标。我们通过分析手部触及的时间和空间轮廓来表征刺激记录。对于交叉双脚的触觉目标，基于皮肤的信息暗示了错误的一侧，并且只有记录的信息才指向正确的位置。参与者开始直接伸手，并将手转向飞行途中出现的目标。视觉目标的轨迹不受脚交叉的影响。相比之下，交叉脚比不交叉脚更晚重定向到触觉目标的轨迹。双脚交叉通常会继续笔直，直到它们被引导至正确的触觉目标并且不偏向基于皮肤的目标位置。当该目标受到试验历史的牵连时，最有可能偶尔出现远偏向错误目标的情况。这些结果与肢体交叉会损害触觉空间变换的建议不一致，但与快速有效地记录触觉位置，然后整合基于皮肤的信息和外部信息来指定到达目标是一致的。该过程可以在有界积分器框架中实现。
Spatial target information for movement planning appears to be coded in a gaze-centered reference frame. In touch, however, location is initially coded with reference to the skin. Therefore, the tactile spatial location must be derived by integrating skin location and posture. It has been suggested that this recoding is impaired when the limb is placed in the opposite hemispace, for example, by limb crossing. Here, human participants reached toward visual and tactile targets located at uncrossed and crossed feet in a sensorimotor decision task. We characterized stimulus recoding by analyzing the timing and spatial profile of hand reaches. For tactile targets at crossed feet, skin-based information implicates the incorrect side, and only recoded information points to the correct location. Participants initiated straight reaches and redirected the hand toward a target presented in midflight. Trajectories to visual targets were unaffected by foot crossing. In contrast, trajectories to tactile targets were redirected later with crossed than uncrossed feet. Reaches to crossed feet usually continued straight until they were directed toward the correct tactile target and were not biased toward the skin-based target location. Occasional, far deflections toward the incorrect target were most likely when this target was implicated by trial history. These results are inconsistent with the suggestion that spatial transformations in touch are impaired by limb crossing, but are consistent with tactile location being recoded rapidly and efficiently, followed by integration of skin-based and external information to specify the reach target. This process may be implemented in a bounded integrator framework.