Callier Thierri, Saal Hannes P, Davis-Berg Elizabeth C, Bensmaia Sliman J
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois;
Department of Science and Mathematics, Columbia College Chicago, Chicago, Illinois; and.
J Neurophysiol. 2015 Apr 1;113(7):3013-20. doi: 10.1152/jn.00703.2014. Epub 2015 Mar 4.
A hallmark of tactile texture exploration is that it involves movement between skin and surface. When we scan a surface, small texture-specific vibrations are produced in the skin, and specialized cutaneous mechanoreceptors convert these vibrations into highly repeatable, precise, and informative temporal spiking patterns in tactile afferents. Both texture-elicited vibrations and afferent responses are highly dependent on exploratory kinematics, however; indeed, these dilate or contract systematically with decreases or increases in scanning speed, respectively. These profound changes in the peripheral response that accompany changes in scanning speed and other parameters of texture scanning raise the question as to whether exploratory behaviors change depending on what surface is explored or what information is sought about that surface. To address this question, we measure and analyze the kinematics as subjects explore textured surfaces to evaluate different types of texture information, namely the textures' roughness, hardness, and slipperiness. We find that the exploratory movements are dependent both on the perceptual task, as has been previously shown, but also on the texture that is scanned. We discuss the implications of our findings regarding the neural coding and perception of texture.
触觉纹理探索的一个标志是它涉及皮肤与表面之间的运动。当我们扫描一个表面时，皮肤中会产生特定于纹理的微小振动，专门的皮肤机械感受器会将这些振动转换为触觉传入神经中高度可重复、精确且信息丰富的时间脉冲模式。然而，纹理引发的振动和传入神经反应都高度依赖于探索运动学；实际上，这些振动会分别随着扫描速度的降低或增加而系统地扩张或收缩。随着扫描速度和纹理扫描其他参数的变化，外周反应发生的这些深刻变化引发了一个问题，即探索行为是否会根据所探索的表面或关于该表面所寻求的信息而改变。为了解决这个问题，我们在受试者探索有纹理的表面以评估不同类型的纹理信息（即纹理的粗糙度、硬度和光滑度）时测量并分析其运动学。我们发现，探索运动既如先前所示依赖于感知任务，也依赖于所扫描的纹理。我们讨论了我们的发现对于纹理的神经编码和感知的意义。
