TACTILE DETECTION OF SLIP - SURFACE MICROGEOMETRY AND PERIPHERAL NEURAL CODES
TACTILE DETECTION OF SLIP - SURFACE MICROGEOMETRY AND PERIPHERAL NEURAL CODES
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DOI：
10.1152/jn.1990.63.6.1323
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发表时间：
1990-06-01
影响因子：
2.5
通讯作者：
LAMOTTE, RH
中科院分区：
文献类型：
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作者：
SRINIVASAN, MA;WHITEHOUSE, JM;LAMOTTE, RH
1. 研究了平面微观几何形状在人类和猴子指腹表面滑动检测中的作用。通过使用伺服控制的触觉刺激器在人类受试者的被动指垫上按压和抚摸玻璃板，确定了人类辨别由摩擦引起的皮肤拉伸方向以及检测具有或不具有微米尺寸表面特征的板的滑动运动（滑动）的能力。为了识别相关的外周神经编码，记录了支配麻醉猕猴指腹的单个低阈值机械感受传入纤维对相同刺激的诱发反应。 2.人类无法察觉指腹上光滑玻璃板的滑动。然而，皮肤拉伸的方向是根据缓慢适应的传入神经传达的信息来感知的，这些传入神经对拉伸方向的反应不同。皮肤拉伸的方向表明即将发生滑动的方向，而板和手指之间相对运动的感知则需要存在可检测的表面特征。 3. 由于迈斯纳 (RA) 或帕西尼亚 (PC) 类型的快速适应纤维对微观特征的特定几何形状的快速适应纤维的独特激活，光滑表面上几乎无法检测到的微米大小的突起导致检测到这些表面的滑动。带有非常小的单个凸起点（4 微米高，550 微米直径）的光滑板的运动引起沿点路径的相邻 RA 的顺序激活，从而提供可靠的时空代码。敲击由点矩阵（1 微米高、直径 50 微米、中心间距 100 微米）组成的精细均匀纹理的板会引起指腹振动，仅激活 PC 并产生密集的代码。 4. 结果表明，人类可以检测到光滑表面上令人惊讶的小特征，并导致检测到这些表面的滑动，而微观特征的几何形状控制着相关的神经代码。当表面特征的尺寸大于所有受体的响应阈值时，冗余的时空和密集信息可用于滑动检测。
1. The role of the microgeometry of planar surfaces in the detection of sliding of the surfaces on human and monkey fingerpads was investigated. By the use of a servo-controlled tactile stimulator to press and stroke glass plates on passive fingerpads of human subjects, the ability of humans to discriminate the direction of skin stretch caused by friction and to detect the sliding motion (slip) of the plates with or without micrometer-sized surface features was determined. To identify the associated peripheral neural codes, evoked responses to the same stimuli were recorded from single, low-threshold mechanoreceptive afferent fibers innervating the fingerpads of anesthetized macaque monkeys. 2. Humans could not detect the slip of a smooth glass plate on the fingerpad. However, the direction of skin stretch was perceived based on the information conveyed by the slowly adapting afferents that respond differentially to the stretch directions. Whereas the direction of skin stretch signaled the direction of impending slip, the perception of relative motion between the plate and the finger required the existence of detectable surface features. 3. Barely detectable micrometer-sized protrusions on smooth surfaces led to the detection of slip of these surfaces, because of the exclusive activation of rapidly adapting fibers of either the Meissner (RA) or the Pacinian (PC) type to specific geometries of the microfeatures. The motion of a smooth plate with a very small single raised dot (4 microns high, 550 microns diam) caused the sequential activation of neighboring RAs along the dot path, thus providing a reliable spatiotemporal code. The stroking of the plate with a fine homogeneous texture composed of a matrix of dots (1 microns high, 50 microns diam, and spaced at 100 microns center-to-center) induced vibrations in the fingerpad that activated only the PCs and resulted in an intensive code. 4. The results show that surprisingly small features on smooth surfaces are detected by humans and lead to the detection of slip of these surfaces, with the geometry of the microfeatures governing the associated neural codes. When the surface features are of sizes greater than the response thresholds of all the receptors, redundant spatiotemporal and intensive information is available for the detection of slip.