Target search and inspection strategies in haptic search

Haptic search is a common everyday task, usually consisting of two processes: target search and target analysis. During target search we need to know where our fingers are in space, remember the already completed path and the outline of the remaining space. During target analysis we need to understand whether the detected potential target is the desired one. Here we characterized dynamics of exploratory movements in these two processes. In our experiments participants searched for a particular configuration of symbols on a rectangular tactile display. We observed that participants preferentially moved the hand parallel to the edges of the tactile display during target<br> search, which possibly eased orientation within the search space. After a potential target was detected by any of the fingers, there was higher probability that subsequent exploration was performed by the index or the middle finger. At the same time, these fingers dramatically slowed down. Being in contact with the potential target, the index and the middle finger moved within a smaller area than the other fingers, which rather seemed to move away to leave them space. These results suggest that the middle and the index finger are specialized for fine analysis in haptic search. The zip file contains all data relative to the publication. The structure of the data of all experiments is described in the README file.触觉搜索（haptic search）是日常常见任务，通常包含目标搜索与目标分析两个流程。在目标搜索阶段，我们需要明确手指在空间中的位置，记忆已完成的探索路径与剩余未探索空间的轮廓。在目标分析阶段，则需判断所检测到的潜在目标是否为预期目标。本研究对这两类流程中的探索运动动力学特征进行了表征。在本实验中，受试者需在矩形触觉显示器（rectangular tactile display）上搜寻特定的符号组合。实验结果显示，受试者在目标搜索阶段更倾向于沿平行于触觉显示器边缘的方向移动手部，此举或可降低搜索空间内的方位认知负荷。当任意一根手指检测到潜在目标后，后续探索更大概率由食指或中指完成，且这两根手指的移动速度会显著降低。当食指与中指接触到潜在目标时，其活动范围相较于其余手指更小；而其余手指则会主动移开，为二者留出操作空间。上述结果表明，食指与中指是触觉搜索中负责精细目标分析的专用手指。本压缩包包含与该论文相关的全部实验数据，所有实验的数据组织结构详见README文件。