Department of Psychology, City University, London, United Kingdom.
Brain Cogn. 2011 Nov;77(2):257-64. doi: 10.1016/j.bandc.2011.08.002. Epub 2011 Sep 7.
How do humans interact with tools? Gibson (1979) suggested that humans perceive directly what tools afford in terms of meaningful actions. This "affordances" hypothesis implies that visual objects can potentiate motor responses even in the absence of an intention to act. Here we explore the temporal evolution of motor plans afforded by common objects. We presented objects that have a strong significance for action (pinching and grasping) and objects with no such significance. Two experimental tasks involved participants viewing objects presented on a computer screen. For the first task, they were instructed to respond rapidly to changes in background colour by using an apparatus mimicking precision and power grip responses. For the second task, they received stimulation of their primary motor cortex using transcranial magnetic stimulation (TMS) while passively viewing the objects. Muscular responses (motor evoked potentials: MEPs) were recorded from two intrinsic hand muscles (associated with either a precision or power grip). The data showed an interaction between type of response (or muscle) and type of object, with both reaction time and MEP measures implying the generation of a congruent motor plan in the period immediately after object presentation. The results provide further support for the notion that the physical properties of objects automatically activate specific motor codes, but also demonstrate that this influence is rapid and relatively short lived.
人类如何与工具互动？吉布森（1979 年）认为，人类可以直接感知工具在有意义的动作方面提供了什么。这种“可供性”假说意味着，即使没有行动的意图，视觉物体也可以激发运动反应。在这里，我们探讨了常见物体提供的运动计划的时间演变。我们展示了对动作有强烈意义的物体（捏和抓）和没有这种意义的物体。两个实验任务涉及参与者观看计算机屏幕上呈现的物体。在第一个任务中，他们被指示通过模仿精密和力量抓握反应的仪器快速响应背景颜色的变化。在第二个任务中，他们在被动观看物体的同时接受经颅磁刺激（TMS）的刺激。从两个内在手部肌肉（与精密或力量抓握相关）记录肌肉反应（运动诱发电位：MEPs）。数据显示，反应类型（或肌肉）和物体类型之间存在相互作用，反应时间和 MEP 测量都暗示在物体呈现后的立即时期产生了一致的运动计划。结果进一步支持了这样一种观点，即物体的物理特性自动激活特定的运动代码，但也表明这种影响是快速且相对短暂的。
