Neural Temporal Coding Mechanisms of Tactile Attention

描述(申请人提供)：人类和高等动物从他们的感官外周获得的信息比他们的中枢神经系统能够处理的详细信息要多得多。选择性注意是一种分类过程，通过这个过程，输入的信息被分成行为上最相关的部分，需要详细处理，以及所有其他被抑制的部分。本研究的目的是了解触觉选择性注意背后的神经机制，将通过单单位记录和局部场电位记录来研究清醒行为猴的触觉选择性注意。第一个目标是确定注意选择的粒度限制。在空间(注意不同的手指或不同的手)、次通道(注意振动或形状)和时间(在一次试验的持续时间内的变化)上的选择的限制是什么，以及这种注意选择的神经元相关性是什么？我们将具体测量平均放电率和神经元之间的相关性(同步)的变化。目的2是确定注意选择对已识别的神经元亚群的反应的影响，包括由皮层和神经元的突触后效应(兴奋或抑制)定义的功能亚群。我们还将确定是否所有显示同步的神经元都是一个种群的一部分，或者是否有几个亚种群的成员彼此同步，但不与其他亚种群的成员同步。关于神经同步性在知觉中的作用的两个理论模型(1：标记注意的刺激，2：标记感知的刺激的不同部分)对亚群的数量做出了不同的预测，本分析将检验这些预测。目标3是研究同步性产生的潜在机制。将被检验的一个假设是动作电位与周期函数(振荡)的相位锁定。

DESCRIPTION (provided by applicant): Humans and higher animals receive much more information from their sensory periphery than they can process in detail by their central nervous system. Selective attention is the triage process by which incoming information is divided into the behaviorally most relevant parts, which require detailed processing, and all others that are suppressed. The goal of this research is to understand the neural mechanisms underlying tactile selective attention which will be studied by single unit recordings and local field potential recordings in awake behaving monkeys. The first Aim is to determine the limits of granularity of attentional selection. What are the limits of selection in space (attend to different fingers or to different hands), submodality (attend to vibration or to form) and time (changes within the duration of one trial), and what are the neuronal correlations of this attentional selection? We will specifically measure changes in mean firing rate and in correlations between neurons (synchrony). Aim 2 is to determine the influence of attentional selection on the responses of identified neuronal subpopulations, including the functional populations defined by the cortical layers and by the postsynaptic effects of neurons (excitation or inhibition). We will also determine whether all neurons showing synchrony are part of one population or whether there are several subpopulations whose members are synchronous with each other but not with members of other subpopulations. Two theoretical models of the role of neural synchrony in perception (1: tagging of the attended stimulus, 2: tagging of different parts of a perceived stimulus) make different predictions for the number of subpopulations and this analysis will test those predictions. Aim 3 is to study the mechanisms underlying the generation of synchrony. One hypothesis that will be tested is phase locking of action potentials to a periodic function (oscillations).