Neural Temporal Coding Mechanisms of Tactile Attention

描述（由申请人提供）：人类和高等动物从他们的感觉外围接收到的信息比他们通过中枢神经系统处理的细节要多得多。选择性注意是一种分类过程，通过这种过程，输入的信息被分成与行为最相关的部分，这些部分需要详细处理，而所有其他部分都被抑制。本研究的目的是了解触觉选择性注意的神经机制，这将通过单单元记录和局部场电位记录在清醒行为的猴子中进行研究。第一个目标是确定注意选择粒度的限制。在空间（注意不同的手指或不同的手）、次模态（注意振动或形状）和时间（在一次试验持续时间内的变化）上的选择的限制是什么？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的变化和神经元之间的相关性（同步）。目的2是确定注意选择对确定的神经元亚群的反应的影响，包括由皮质层和神经元的突触后效应（兴奋或抑制）定义的功能群。我们还将确定是否所有显示同步的神经元都是一个群体的一部分，或者是否有几个亚群体的成员彼此同步，但与其他亚群体的成员不同步。神经同步在感知中的作用有两种理论模型（1：标记参与的刺激，2：标记感知刺激的不同部分）对亚种群的数量做出了不同的预测，本分析将对这些预测进行检验。目的3是研究同步产生的机制。将要测试的一个假设是动作电位的周期函数锁相（振荡）。

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).