Attention and Tactile Processing in Somatosensory Cortex

描述（由申请人提供）：资金要求继续我们的研究，形状是如何表示和处理的躯体感觉系统，并确定这些表示是如何调制的选择性注意。在这个建议中，我们专注于确定如何从多个数字的信息被整合，形成中央表示的对象形状。这些研究建立在我们以前的研究基础上，表明体感皮层中的许多神经元对定向杆表现出特征选择性反应，选择性是以皮肤为中心的坐标，并且灵敏度受到手部构造变化的调制。根据这些发现，我们假设形状感知是基于神经元群体将接触点与手指的位置相结合。有两个（2）具体目标。第一个是调查如何在二维（2D）形状的处理过程中的接触点集成。在这些实验中，接触多个手指的形状被分解成特征，这些特征将单独或与其他特征相结合地呈现给手，同时动物执行一个视觉匹配任务。这项研究将确定对象的独立视图如何跨数字整合，以形成二维（2D）对象的神经表征。这项研究还将确定注意力在触觉特征结合中所起的作用。第二个目的是确定如何通过手构造来调制特征选择性。在这些实验中，动物将接受训练，用一个或多个手指抓取三维（3D）物体。物体被选择为使得它们跨越动物和人类在抓取物体时使用的构象空间。这些实验将测试的假设，形状感知是由群体的神经元与功能选择性反应调整到特定的手的构象编码。实验将在初级（SI）和次级（SII）躯体感觉皮层中进行。

DESCRIPTION (provided by applicant): Funds are requested to continue our studies of how the shape is represented and processed in the somatosensory system and to determine how those representations are modulated by selective attention. In this proposal we concentrate on determining how information from multiple digits are integrated to form central representations of object shape. These studies build on our previous studies showing that many neurons in somatosensory cortex show feature selective responses to oriented bars, the selectivity is in skin centered coordinates, and the sensitivity is modulated by changes in hand conformation. From those findings we hypothesize that shape perception is based on populations of neurons integrating points of contact with the positions of the fingers. There are two (2) specific aims. The first is to investigate how the points of contact are integrated during the processing of two-dimensional (2D) shapes. In these experiments, shapes that contact multiple digits are decomposed into features that will be presented to the hand either alone or in combination with other features while the animal performs a tactile-visual matching task. This study will determine how independent views of objects are integrated across digits to form neural representations of two-dimensional (2D) objects. The study will also determine the role that attention plays in the binding of tactile features. The second aim is to determine how feature selectivity is modulated by hand conformation. In these experiments, animals will be trained to grasp three-dimensional (3D) objects with one (1) or more digits. The objects are chosen such that they span the conformational space that animals and humans use when grasping objects. These experiments will test the hypothesis that shape perception is encoded by populations of neurons with feature selective responses tuned to specific hand conformations. Experiments will be performed in primary (SI) and secondary (SII) somatosensory cortex.