Neural mechanisms of size and shape perception in somatosensory cortex

需要资金来研究体感系统中三维(3D)形状和大小感知的神经机制。局部表面特征的感知是基于支配皮肤的机械感受性传入的活动，而物体的整体特征，如形状和大小，则基于手和手指的位置以及来自与物体多个接触点的皮肤信息。项目1集中于如何集成来自多个接触点的信息；本项目(3)集中于手和手指位置在3D表单处理中的作用。其目的是研究清醒猴子的SI和SII大脑皮层如何整合来自手指内部和手指之间的触觉和本体感受器的信息，以提供有关物体的3D形状和大小的信息。目的1是通过研究不同屈曲组合的相邻手指之间的触觉信息整合来研究形状信息的加工，模拟与不同形状物体的接触。目的2是通过研究数字扩散如何影响体感神经元对局部刺激专利的反应，来研究有关物体大小的信息的加工。将使用主动和被动两种刺激模式。在被动模式下，与单个曲面(目标1)一致或不一致的刺激(目标1)或刺激特定大小的物体(目标2)将在动物执行触觉匹配样本任务时应用于手。在主动模式下，动物会主动移动手指，以接触曲率和大小不同的刺激。通过这种方式，我们将研究躯体感觉皮质不同区域中物体大小和形状的神经元反应调节，并确定在主动触摸和被动触摸期间调节是否有所不同。

Funds are requested to study the neural mechanisms underlying three- dimensional (3D) shape and size perception in somatosensory system. While the perception of local surface features is based on the activity in the mechanoreceptive afferents innervating the skin, gross object features such as shape and size are based on hand and finger position and cutaneous information from multiple points of contact with the object. Project 1 concentrates on how information is integrated from the multiple points of contact; This project (3) concentrates on the role of hand and finger position in 3D form processing. The aim is to study how information from tactile and proprioceptors within and between digits are integrated in SI and SII cortex of the awake monkey to provide information about the 3D shape and size of objects. Aim 1 is to investigate the processing of shape information by studying the integration of tactile information across adjacent digits positioned at different combinations of flexion, simulating contact with objects with varying shapes. Aim 2 is to investigate the processing of information about object size by studying how digit spread affects the responses of somatosensory neurons to local patents of stimulation. Two modes of stimulation, active and passive, will be used. In the passive mode stimuli that are or are not consistent with a single curved surface (aim 1) or stimulate an object of a specified size (aim 2) will be applied to the hand while the animal performs a tactile match-to-sample task. In the active mode, the animal actively moves it fingers to contact the stimuli that vary in curvature and size. In this manner we will study neuronal response tuning for object size and shape in various areas in the somatosensory cortex and determine and whether the tuning differs during active and passive touch.