Representation of three dimensional shape features in somatosensory cortex

体感皮层三维形状特征的表示

• 批准号: 6480803
• 负责人: KENNETH O JOHNSON
• 金额: $ 15.58万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6480803
• 关键词: Macaca mulatta; computational neuroscience; electrostimulus; fingers; form /pattern perception; hand; microelectrodes; neural information processing; orientation; proprioception /kinesthesia; sensory signal detection; skin; somesthesis; somesthetic sensory cortex; stimulus /response; surface property; touch

The perception of 3D form depends on hand conformation and the integration of stimuli of stimuli from the multiple points of contact with the hand. To understand the neural mechanisms underlying stereognosis we need to understand three things: 1) how neurons respond to surface structure at the individual points of contact, 2) how a stimuli at separate regions of skin are integrated, and 3) how this integration depends on hand conformation. The experiments proposed here are aimed at taking a first step towards understanding these three facets of 3D form perception. Aim 1 is to determine how neurons in SI and SII cortex respond to 3D surface structure contacting a single finger. This study will be limited to surface curvature and edges of the kind that occurs when a finger contacts a rigid object. 3D surface structure varies in the plane parallel to and normal to the skin surface. The experiments related to aim 1 will study neural responses to edges and corners whose orientation and curvature vary in the plane parallel to the skin surface and neural responses to surface curvature normal to the skin surface. Aim 2 is to determine how neurons in SI and SII cortex respond to stimuli presented to two fingers. Surfaces indenting tow finger tips signal different things about an object depending on the surfaces' relative motions, orientations, and curvatures. Experiments related to aim 2 will study 1) the effects of stimulus direction and velocity; b) the effects of edge orientation, and c) the effects of surface curvature and slope on adjacent fingers. Aim 3 is to determine the neural mechanisms of objective constancy in the face of varying finger position. When we scan our fingers over an object the primary information from two or more fingers varies with finger spread but the percept is unaffected. The experimented related to Aim 3 concentrate on the convergent mechanisms (between proprioceptive and cutaneous information) that must operate to compensate for finger position when abduction varies.

3D形式的感知取决于手动构象和从与手接触的多个接触点的刺激刺激的整合。为了了解立体认知基础的神经机制，我们需要理解三件事：1）神经元如何在各个接触点上对表面结构做出反应，2）如何整合皮肤的单独区域的刺激以及3）这种整合如何取决于手部构象。这里提出的实验旨在迈出第一步，以了解3D形式感知的这三个方面。 AIM 1是确定SI和SII皮层中的神经元如何响应3D表面结构接触单个手指。这项研究将仅限于表面曲率和当手指接触刚性物体时发生的那种边缘。 3D表面结构在平行于皮肤表面的平面和正常状态下变化。 与AIM 1相关的实验将研究对边缘和角落的神经反应，其方向和曲率在平行于皮肤表面的平面以及对皮肤表面正常表面表面曲率的神经反应之间有所不同。 AIM 2是确定SI和SII皮层中的神经元如何响应两个手指的刺激。表面缩进拖曳指尖，根据表面的相对运动，方向和曲线，有关对象的不同事物。与AIM 2相关的实验将研究1）刺激方向和速度的影响； b）边缘方向的影响，c）表面曲率和斜率对相邻手指的影响。目的3是在面对不同的手指位置的情况下确定客观恒定的神经机制。当我们在一个物体上扫描手指时，来自两个或多个手指的主要信息随着手指的张开而变化，但感知不受影响。与AIM 3有关的实验集中于收敛机制（在本体感受和皮肤信息之间），该机制必须在外演展变化时必须运行以补偿手指位置。