Haptic Perceptual Instruments

触觉是指一个人通过身体中的传感器对自己的身体以及对身体的依附的感知。这个词包含了通常所说的“触摸”，以及更多的东西。例如，在没有视觉优势的情况下，一个人可以知道自己四肢的位置，也可以通过挥舞和举起物体来确定物体的属性(例如，重量、长度)。触觉感知的这些方面被称为动态触摸，它们的基础是感知肌肉和肌腱状态的感受器。与视觉和听觉不同，视觉和听觉对日常活动的重要性是显而易见的，而触觉感知系统对我们日常感知和行动的成就的贡献是惊人的微妙。触觉丧失(没有伴随的瘫痪)是极其罕见的，而且具有深远的破坏性，这一事实开始说明这种感觉在常见活动中的基本重要性，比如举起杯子、使用钢笔、指着一个词，或者只是直立站立。我们的研究针对的是动态触摸和理解它在日常可控操作中所起的作用。我们问，它能做什么？；它是如何做到的？到目前为止的研究表明，肢体运动的旋转动力学是这两个问题的主要制约因素，这是拟议的研究中所追求的。从形式上讲，动态触摸的成就与惯性张量(量化物体对旋转的阻力)和姿态旋量(量化物体相对于某个参照系，如手)有关。在一些基本方法中，参与者挥舞着一个看不见的物体(其结构经过特殊设计，以产生实验上相关的惯性张量或姿态旋量)，以感知其长度、宽度、形状、重量或手的方向。在其他基本方法中，参与者试图将不可见的上肢或肢体节段(带有系统地控制肢体的惯性张量和姿态旋量的夹板)定向到环境目标或另一个不可见的肢体。一个主要的论点是，在动态触摸感知中，与手相关的触觉子系统表现为一种智能工具：它利用物理的、基于法律的不变量。实验的目的是检查不同的注意力需求(以及不同属性在感知上独立的程度)、不同的力结构(如水下和旋转空间站中经历的那些)以及在不同的神经条件下(如肌腱受到电磁振动时产生的虚假感受器状态)的后果。理解控制动态触摸的原理应该会丰富感知系统的计算和神经建模的物理约束，并提供关于躯体感觉障碍以及假肢和机器人肢体设计的新假说来源。这样的理解可能还会促使人们更深入地研究生物感知-行为系统形成的物理原理，以及利用它们的认知和神经限制。S获得了美国国家自然科学基金重大研究仪器项目的部分资助。

Haptic perception refers to the perception one has of one's body, and of attachments to it, by means of sensors in the body. The term incorporates what is commonly meant by `touch,` and more besides. For example, without benefit of vision one is aware of the positions of one's limbs, and one can also ascertain properties of objects (e.g., weight, length)by wielding and hefting them. These aspects of haptic perception, referred to as dynamic touch, have their basis in receptors that sense the states of muscles and tendons. Unlike vision and audition, whose importance to everyday activity are obvious, the haptic perceptual system is strikingly subtle in its contribution to our everyday achievements of perceiving and acting. The fact that the loss of the sense of touch (without concomitant paralysis) is extremely rare and profoundly devastating begins to illustrate the fundamental importance of this sense in common activities such as lifting a cup, using a pen, pointing to a word, or just standing upright. Our research is directed at dynamic touch and an understanding of the role it plays in everyday controlled manipulations. We ask, What can it do?; and, How does it do it? Research to date has implicated the rotational dynamics of limb movements as the major constraint on both of these questions, and this is pursued in the proposed research. Formally, the achievements of dynamic touch are related to the inertia tensor (which quantifies an object's resistance to being rotated) and the attitude spinor (which quantifies an object's orientation relative to some reference frame such as the hand). In some of the basic methodologies, participants wield an unseen object (whose structure has been specially contrived to produce the experimentally relevant inertia tensor or attitude spinor) to perceive its length, width, shape, weight, or orientation to the hand. In other basic methodologies, the participants attempt to orient a nonvisible upper limb or limb segment (with attached splints that systematically control the limb's inertia tensor and attitude spinor) to an environmental target or to another nonvisible limb. A major thesis is that, in perception by dynamic touch, the hand-related haptic subsystem behaves as a smart instrument: It capitalizes on physical, law-based, invariants. Experiments are designed to examine the consequences of different attentional demands (and the extent to which different properties are perceptually independent), different force structures (such as those experienced underwater and in rotating space stations), and in different neural conditions (such as the spurious receptor states produced when the tendons are vibrated electromagnetically). Understanding the principles governing dynamic touch should enrich the physical constraints on computational and neural modeling of perceptual systems and provide a source of new hypotheses about somatosensory disorders and about designs for prosthetic and robot limbs. Such understanding might also be expected to motivate more intensive study of the physical principles formative of biological perception-action systems and of the cognitive and neural constraints that exploit them. s partly supported by the NSF Major Research Instrumentation Program.