Tactile discrimination of textured surfaces: peripheral neural coding in the monkey.
Tactile discrimination of textured surfaces: peripheral neural coding in the monkey.
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纹理表面的触觉辨别：猴子的周围神经编码。
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
G. Lamb
中科院分区：
文献类型：
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作者：
G. Lamb
通过麻醉猴子的正中神经或尺神经的单个机械感受传入神经进行记录，同时通过在皮肤上匀速切向移动的纹理表面刺激相应的数字垫。表面多次扫过传入的接受野，每次都有少量的侧向移位。神经反应表现出一种时间节奏，与表面上与运动方向平行的维度上凸起点的周期直接相关。响应也显示出直接依赖于点的位置和周期大小的横向表面尺寸。很明显，只有来自大量传入的信息才能对所检查的纹理表面进行区分。对于大点（2.0 mm周期）表面，在点的周期内，无论在哪个表面尺寸上，增加高达8%，每个快速适应（r.a.）传入的平均响应率都大致呈线性增加。当点的周期以类似的小幅度增加时，任何缓慢适应（s.a）传入的反应率几乎没有变化，而pacinian传入（p.c）对这种周期变化表现出广泛的行为。相比之下，在小点（1.0 mm周期）表面的情况下，三个种群中p.c.事件的平均响应率似乎最能传递有关周期变化的信息。在前一篇论文（Lamb, 1983）中报告的所有心理物理歧视中，一些神经编码的充分性得到了检验。基于大点表面的r.a.传入响应和小点表面的p.c.传入响应（不太确定），可以对涉及所诱发脉冲总数或平均次数（速率码）的编码做出强有力的说明。
Recordings were made from single mechanoreceptive afferents in the median or ulnar nerve of the anaesthetized monkey while the appropriate digital pad was stimulated by a textured surface moving at a constant velocity tangentially across the skin. The surface was swept across the afferent's receptive field many times, each time having been displaced sideways (laterally) by a small amount. The neural responses showed a temporal rhythm directly related to the period of the raised dots on the surface in the dimension parallel to the direction of movement. The responses also displayed direct dependence on the position of the dots and the period size in the lateral surface dimension. It was clear that only information from a large number of afferents could enable the discrimination of the textured surfaces examined. For large‐dot (2.0 mm period) surfaces, increases of up to 8% in the period of the dots, in either surface dimension, produced a roughly linear increase in the mean response rate of every rapidly adapting (r.a.) afferent. There was virtually no change in the response rate of any slowly adapting (s.a.) afferent when the period of the dots was increased by similar small amounts, and the pacinian afferents (p.c.) displayed a wide range of behaviour to such period changes. In contrast, the mean response rate of p.c. afferents seemed most able of the three populations to transmit information about changes in the period in the case of small‐dot (1.0 mm period) surfaces. The adequacy of a number of neural codes in accounting for all the psychophysical discrimination reported in the preceding paper (Lamb, 1983) was examined. A strong case could be made for a code involving the total or mean number of impulses evoked (a rate code), based on the r.a. afferent responses for the large‐dot surfaces and, less certainly, on the p.c. afferent responses for the small‐dot surfaces.