Attention and Tactile Processing in Somatosensory Cortex

描述(由申请者提供)：需要资金继续我们对体感系统中形状是如何呈现和处理的研究，并确定这些呈现是如何通过选择性注意来调节的。在该方案中，我们集中于确定如何将来自多个数字的信息整合以形成对象形状的中心表示。这些研究建立在我们之前的研究基础上，表明躯体感觉皮层中的许多神经元对定向条状突起表现出特征选择性反应，这种选择性是在以皮肤为中心的坐标下进行的，并且这种敏感性受到手部构象变化的调节。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整合在一起。有两(2)个具体目标。第一个是研究在处理二维(2D)形状的过程中接触点是如何整合的。在这些实验中，接触多个手指的形状被分解成特征，当动物执行触觉-视觉匹配任务时，这些特征将单独或与其他特征一起呈现给手。这项研究将确定对象的独立视图如何跨数字整合，以形成二维对象的神经表示。这项研究还将确定注意力在触觉特征绑定中所起的作用。第二个目标是确定手性构象是如何调节特征选择性的。在这些实验中，动物将被训练用一(1)个或多个手指抓取三维(3D)物体。这些物体是这样选择的，它们跨越动物和人类抓取物体时使用的构象空间。这些实验将检验这样一个假设，即形状感知是由一群神经元编码的，这些神经元的特征选择反应调节到特定的手的构型。实验将在初级(SI)和次级(SII)躯体感觉皮层进行。

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.