Natural motor behavior is usually refined by ongoing sensory input in closed feedback loops. Research has suggested that humans make systematic errors when localizing touch on the skin, and that perceptual body representations underlying these behaviors are distorted. However, experimental procedures usually prevent participants from touching the target limb, interrupting the natural action-perception loop. It is currently unknown how such experimental strategies affect localization and systematic perceptual distortions. Here, participants received a brief touch on their left forearm and, with closed eyes, searched for the target location by moving the right index finger across the left arm. Tactile search significantly reduced the localization error present at touchdown of the searching finger on the target arm. Localization improvement was largely absent when a barrier above the target arm prevented online tactile feedback of the target region. Vision of the arms while reaching to, and searching on, the skin, greatly reduced the localization error at touchdown, but tactile search further improved localization slightly. Thus, both tactile and visual feedback help matching the positions of reaching and target limbs during localization. Yet, even if small, the unique improvement through tactile information confirms the importance of target-related, closed-loop tactile feedback for tactile localization. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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主动搜索过程中的在线感官反馈可改善触觉定位。

通常通过闭合反馈回路中不断进行的感觉输入来改善自然运动行为。研究表明，人类在皮肤上进行局部接触时会犯系统错误，并且这些行为背后的知觉身体表征会失真。但是，实验程序通常会阻止参与者触摸目标肢体，从而中断自然的动作感知循环。目前尚不清楚这样的实验策略如何影响定位和系统的知觉失真。在这里，参与者对他们的左前臂进行了短暂的触摸，闭着眼睛，通过右食指在左臂上移动来搜索目标位置。触觉搜索显着减少了搜索手指触及目标手臂时出现的定位误差。当目标臂上方的障碍物阻止了目标区域的在线触觉反馈时，本地化的改进就基本上不存在了。手臂到达并搜索皮肤时的视力大大降低了触地时的定位误差，但触觉搜索进一步略微改善了定位。因此，触觉和视觉反馈都有助于在定位过程中匹配到达肢体和目标肢体的位置。然而，即使很小，通过触觉信息的独特改进也证实了与目标相关的闭环触觉反馈对于触觉定位的重要性。（PsycInfo数据库记录（c）2020 APA，保留所有权利）。大大降低了触地时的定位错误，但触觉搜索进一步改善了定位。因此，触觉和视觉反馈都有助于在定位过程中匹配到达肢体和目标肢体的位置。然而，即使很小，通过触觉信息的独特改进也证实了与目标相关的闭环触觉反馈对于触觉定位的重要性。（PsycInfo数据库记录（c）2020 APA，保留所有权利）。大大降低了触地时的定位错误，但触觉搜索进一步改善了定位。因此，触觉和视觉反馈都有助于在定位过程中匹配到达肢体和目标肢体的位置。然而，即使很小，通过触觉信息的独特改进也证实了与目标相关的闭环触觉反馈对于触觉定位的重要性。（PsycInfo数据库记录（c）2020 APA，保留所有权利）。