Dual Feedback Streams and Laminar Integration of Long-range Inter-areal Processes in the Early Visual System

早期视觉系统中远程区域间过程的双反馈流和层整合

• 批准号: 431394854
• 负责人: Professor Dr. Pascal Fries
• 金额: --
• 依托单位: Stem Cell and Brain Research Institute (SBRI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/431394854?language=en
• 关键词: Dual; Feedback; Streams; Laminar; Integration

Cortical feedback plays a critical role in perceptual-cognitive integration and in major hypotheses on brain function, including predictive coding theory. We aim to investigate the integrative roles of two feedback pathways that have been identified in the inter-areal projections of primate cerebral cortex in the framework of a multidisciplinary project that will use neuroimaging, electrophysiology and anatomy. The two feedback pathways in supra- and infragranular cortical layers show distinct topographical features: a long-distance, diffusely projecting pathway in infragranular layers and a short-distance pathway whose projections are more focal and confined to supragranular layers. Importantly, the specific functions of these two pathways are unknown. Objectives 1 and 2 probes these pathways by studying laminar dependent activity in early visual areas during cognitive tasks requiring perceptual integration and attention in human and nonhuman primates while performing tasks requiring long-range cortical interaction: figure/ground, motion coherence and spatial vs feature selective attention. Objective 1, in human, uses laminar-resolution functional imaging with fMRI at 7T to explore what stimulus conditions generate differential activation of supra and infragranular layers and causal modeling to infer directed inter-areal effective connectivity. We will explore three tasks: (1) contextual effects on surface color perception that influence (i) the visual stream of origin of feedback signals and (ii) stimulus predictability; (2) the influence of motion coherence and stimulus expectation on feedback to early visual areas; (3) the role of spatial and feature selective attention on the laminar profile of activity. We expect that these experiments will reveal conditions that differentially affect the two feedback streams, thus, informing us about their different functional roles. Objective 2, in marmoset uses multi-site depth electrodes to assess layer-specific activation patterns and directed inter-areal interactions via layer-specific optogenetic activation of the two feedback pathways to probe their causal relevance. We expect that the results will inform us about the differential roles of the two feedback pathways in cortical processing, which will allow more accurate models of cortical processing to be developed in a predictive coding framework. Objective 3 addresses the nature and frequency of long-distance inhibitory connections between cortical areas and interstitial neurons and cortex, investigating if they are preferentially associated with a particular circuit. Such inhibitory processes are predicted to have profound impact on inter-areal processing through effects on oscillation and synchrony. We predict the proposed work will contribute to understanding the canonical cortical microcircuits and the computations they support in a predictive coding framework and thereby furthering understanding the neuronal basis of psychiatric disorders.

皮层反馈在感知-认知整合和大脑功能的主要假设中起着关键作用，包括预测编码理论。我们的目标是调查的整合作用的两个反馈途径，已确定在区域间的灵长类动物大脑皮层的投影在一个多学科的项目，将使用神经影像学，电生理学和解剖学的框架。两个反馈途径在上和颗粒下皮层层显示出不同的地形特征：一个长距离，弥漫性的投射途径在颗粒下层和短距离的途径，其预测是更集中的，并局限于颗粒上层。重要的是，这两种途径的具体功能尚不清楚。目的1和2探讨这些途径，通过研究层状依赖活动在早期视觉领域的认知任务，需要知觉整合和注意在人类和非人类灵长类动物，同时执行任务，需要长距离皮层互动：图形/地面，运动连贯性和空间与功能选择性注意。目的1，在人类中，使用分层分辨率功能成像与功能磁共振成像在7 T，以探索什么刺激条件下产生差异激活的上和下颗粒层和因果建模，以推断定向区域间的有效连接。我们将探讨三项任务：（1）对表面颜色感知的上下文效应，影响（i）反馈信号的视觉流和（ii）刺激的可预测性;（2）运动连贯性和刺激预期对早期视觉区域反馈的影响;（3）空间和特征选择性注意对活动层轮廓的作用。我们期望这些实验将揭示差异影响两个反馈流的条件，从而告知我们它们不同的功能角色。目的2，在绒猴中使用多位点深度电极来评估层特异性激活模式，并通过两种反馈途径的层特异性光遗传学激活来定向区域间相互作用，以探索它们的因果关系。 我们希望，结果将告知我们的两个反馈途径在皮层处理的不同作用，这将允许更准确的模型，皮层处理的预测编码框架中开发。 目的3解决的性质和频率之间的长距离抑制连接皮层区和间质神经元和皮层，调查他们是否优先与一个特定的电路。这种抑制过程被预测通过对振荡和同步性的影响对区域间加工产生深远的影响。我们预测，拟议的工作将有助于理解典型的皮质微电路和计算，他们支持的预测编码框架，从而进一步了解精神疾病的神经元基础。