Haptic identification of surfaces as fields of force
Haptic identification of surfaces as fields of force
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DOI：
10.1152/jn.00610.2005
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发表时间：
2006-02-01
影响因子：
2.5
通讯作者：
Mussa-Ivaldi, FA
中科院分区：
文献类型：
--
作者：
Chib, VS;Patton, JL;Mussa-Ivaldi, FA
区分对象的形状和机械性能与触摸的能力是最基本的体感功能之一。当探索物体的物理特性（例如刚度和曲率）时，人类会探测物体的表面，并从上肢的许多感觉受体中获取信息。这些感官信息对于行动的指导至关重要。我们研究了人类如何获得表面的形状和机械性能的内部表示，以及该信息如何影响表面上的轨迹的执行。实验涉及执行轨迹的受试者，同时持有平面策略，该平面构成具有可变形状和机械性能的平面虚拟对象。指示受试者在弯曲的刚度和曲率变化的曲线虚拟磁盘上的点之间的手之间进行动作。结果表明自适应反应的两个分类：力扰动和对象边界。在第一种情况下，通过反对相互作用力来实现直线手动运动。在第二种情况下，轨迹符合对象边界，以减少相互作用力。尽管这种二分法对于非常刚性和非常柔软的物体显而易见，但物体边界分类的可能性取决于平滑而单调的方式，在初始运动中经历的平均力量。此外，在各种刚度值中观察到的响应导致适应后恒定的平均相互作用力。这表明神经系统可以通过试图建立恒定相互作用力的机制从两个反应中选择。
The ability to discriminate an object's shape and mechanical properties from touch is one of the most fundamental somatosensory functions. When exploring physical properties of an object, such as stiffness and curvature, humans probe the object's surface and obtain information from the many sensory receptors in their upper limbs. This sensory information is critical for the guidance of actions. We studied how humans acquire an internal representation of the shape and mechanical properties of surfaces and how this information affects the execution of trajectories over the surface. Experiments involved subjects executing trajectories while holding a planar manipulandum that renders planar virtual objects with variable shape and mechanical properties. Subjects were instructed to make reaching movements with the hand between points on the boundary of a curved virtual disk of varying stiffness and curvature. The results suggest two classifications of adaptive responses: force perturbations and object boundaries. In the first case, a rectilinear hand movement is enforced by opposing the interaction forces. In the second case, the trajectory conforms to the object boundary so as to reduce interaction forces. While this dichotomy is evident for very rigid and very soft objects, the likelihood of an object boundary classification depended, in a smooth and monotonic way, on the average force experienced during the initial movements. Furthermore, the observed response across a variety of stiffness values lead to a constant average interaction force after adaptation. This suggests that the nervous system may select from the two responses through a mechanism that attempts to establish a constant interaction force.