Neural mechanisms of size and shape perception in somatosensory cortex

要求基金研究躯体感觉系统中三维形状和大小知觉的神经机制。虽然局部表面特征的感知是基于神经支配皮肤的机械感受性传入神经的活动，但总体对象特征（诸如形状和大小）是基于手和手指位置以及来自与对象接触的多个点的皮肤信息。项目1集中于如何从多个接触点集成信息;该项目（3）集中于手和手指位置在3D形状处理中的作用。其目的是研究如何从触觉和本体感受器内和手指之间的信息被整合在清醒的猴子的SI和SII皮层，以提供有关物体的3D形状和大小的信息。目的1是通过研究位于不同屈曲组合的相邻手指的触觉信息的整合来研究形状信息的处理，模拟与不同形状的物体的接触。目的二是通过研究数字扩展如何影响躯体感觉神经元对局部刺激的反应，探讨物体大小信息的加工。将使用两种刺激模式，主动和被动。在被动模式中，当动物执行触觉与样本匹配任务时，将对手部施加与单个曲面（目标1）一致或不一致的刺激或刺激指定尺寸的物体（目标2）。在主动模式中，动物主动地移动其手指以接触曲率和大小不同的刺激。以这种方式，我们将研究神经元的反应调谐对象的大小和形状在不同的区域在躯体感觉皮层和确定和调谐是否不同，在主动和被动触摸。

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.