Reaching beyond spatial perception: Effects of intended future actions on visually guided prehension
Reaching beyond spatial perception: Effects of intended future actions on visually guided prehension
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DOI：
10.1080/13506280344000329
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发表时间：
2004-02-01
期刊：
影响因子：
2
通讯作者：
Keen, R
中科院分区：
文献类型：
--
作者：
Johnson-Frey, SH;McCarty, ME;Keen, R
三项实验检验了操纵演员关于即将采取的行动的意图是否会影响视觉引导、抓握动作的时间进程和运动学。受试者执行两步动作序列，其中初始动作总是涉及伸手抓住并抓住位于恒定距离的立方体。第二次运动的要求被系统地操纵。尽管空间参数（立方体大小和距离）在所有条件下保持不变，但初始运动的持续时间根据对象在手中后打算执行的动作而有很大差异。当目的是将小立方体 (1 cm(3)) 运送到工作空间上的新位置时，与大立方体 (4 cm(3)) 相比，当目标只是将其提升到当前静止位置上方时，接合小立方体 (1 cm(3)) 所需的时间更少（实验 1）。初始移动持续时间的差异反映了当任务不需要将立方体运输到工作区上的新位置时，在到达的减速阶段花费更多的时间。此外，这种上下文效应与预期第二个动作的准确性要求（实验 2）或复杂性（实验 3）无关。这些发现表明，行动既取决于即时运动的感知空间需求，也取决于整个行动序列的预期目标。
Three experiments examined whether manipulating actors' intentions, regarding forthcoming actions, influences the time course and kinematics of visually guided, reach-to-grasp movements. Subjects performed two-step action sequences where the initial movement always involved reaching for and grasping cubes located at a constant distance. Demands of the second movement were systematically manipulated. Although the spatial parameters (cube size and distance) remained constant across all conditions, the durations of the initial movements differed substantially depending on the actions subjects intended to perform once the objects were in hand. Less time was required to engage a small (1 cm(3)) cube when the intention was to transport it to a new location on the workspace vs. a large (4 cm(3)) cube when the goal was to merely lift it above its current resting position (Experiment 1). This difference in duration of the initial movement reflects more time spent in the deceleration phase of the reach when the task does not require transporting the cube to a new location on the workspace. Further, this context effect is not related to accuracy demands (Experiment 2), or complexity (Experiment 3) of the intended second movement. These findings demonstrate that actions are determined both by the perceived spatial demands of the immediate movement as well as the intended goal of the entire action sequence.