INTEGRATIVE APPROACH TO CORTICAL COGNITIVE NETWORKS

该项目有两个主要目标。第一个是确定在工作记忆过程中，认知神经元网络的结构和功能特性的联合皮层（前额叶和后顶叶）。第二个目标主要是方法：证实工作记忆中神经活动和血液动力学变化之间的耦合。这两个目标将在猴子中追求的四个微创和行为兼容的记录方法的组合使用：近红外光谱（NIRS），表面场电位（FP）记录，局部场电位（LFP）记录，和单位活动记录。将使用硬膜外探头同时记录NIRS信号和表面FP。还将通过经硬膜微电极同时记录单位活动和局部场电位（LFP）。基于认知网络架构的某些假设和每种方法的空间分辨率，这四种方法将组合使用，以测试在两个工作记忆任务，空间延迟响应（DR）和非空间延迟匹配到样本（DMS）的性能期间感兴趣区域的神经激活和血液动力学变化的三个特定假设。分析将集中在神经和血液动力学活动的感觉刺激在工作记忆中的保留。NIRS、FP和单位数据将与与待测试的特定假设最相关的每个变量相关：皮质位置、刺激或记忆、任务、试验时间和正确表现水平。在认知功能的神经-血流动力学耦合的研究中，将特别强调NIRS信号和细胞放电的电表现之间的相关性。这些相关性预计将提供关键信息的神经元基础上的功能成像信号，如BOLD功能磁共振成像，在人类认知。

This project has two major objectives. The first is to identify structural and functional properties of cognitive neuronal networks in cortex of association (prefrontal and posterior parietal) during working memory. The second objective is largely methodological: to substantiate the coupling between neural activity and hemodynamic changes in working memory. Both objectives will be pursued in the monkey by the combined use of four minimally invasive and behavior-compatible recording methods: near-infrared spectroscopy (NIRS), surface field-potential (FP) recording, local field-potential (LFP) recording, and unit-activity recording. NIRS signals and surface FPs will be recorded simultaneously with epidural probes. Unit activity and local field potentials (LFPs) will also be recorded simultaneously by means of transdural microelectrodes. Based on certain assumptions of cognitive network architecture and the spatial resolution of each method, the four methods will be used in combination to test three specific hypotheses of neural activation and hemodynamic change in the regions of interest during the performance of two working-memory tasks, spatial delayed response (DR) and non-spatial delayed matching to sample (DMS). The analysis will focus on the neural and hemodynamic activity during the retention of a sensory stimulus in working memory. NIRS, FP, and unit data will be correlated with each of the variables most relevant to the specific hypotheses to be tested: cortical location, stimulus or memorandum, task, time of trial, and level of correct performance. In the study of neural-hemodynamic coupling in cognitive function, special emphasis will be placed on the correlations between NIRS signals and electrical manifestations of cell discharge. These correlations are expected to provide crucial information on the neuronal basis of functional imaging signals, such as those obtained by BOLD fMRI, in human cognition.