The functional role of frontal and parietal feedback to visual cortex in selective visual attention

项目概述：想象一下纽约市的时代广场：高楼林立，灯光闪烁，一群 人民。这一视觉场景代表了感官信息的潜在过载。为了引导行为，大脑 使用一组过滤机制，这些机制可以加速行为相关信息的处理 或抑制对分散注意力的信息的处理。感官选择性加工过程中的损伤 信息可能对人类健康产生严重后果。例如，这样的后果是显而易见的， 与中风相关的视觉偏盲，以及一些神经发育障碍，如注意力 缺陷多动障碍(ADHD)和自闭症谱系障碍(ASD)。本提案具体而言 重点关注视觉空间中位置的选择性加工，称为空间注意。一场大规模的 大脑区域网络引导空间注意力，但每个网络节点对空间注意力的具体贡献 与注意力相关的增强和抑制在很大程度上仍然是未知的。这里，我们将测试DISTINCT 注意网络中的电路在一个特征明确的区域驱动着这些互补过程 视皮层，即视区4(即，V4)。我们将专门研究来自两个 猕猴注意网络的皮质结节：额叶皮质和外侧的额叶眼野 顶叶皮质的顶内区(LIP)。FEF和LIP都有助于自上而下的注意控制，基于 行为目标。为了确定是否有不同的或冗余的神经回路潜在的影响 注意相关的增强和抑制对视觉处理，我们将记录层特定神经 来自V4的活性，同时使用光遗传学(即使用遗传编码的光驱动离子 通道或泵)以停用已知的皮质通路，从FEF到V4或从LIP到V4。这个 光遗传学的使用，与其他因果操作(例如，电微刺激或 药理失活)，将允许我们(I)从特定的区域间分离贡献， 以及(Ii)比较来自FEF或LIP的失活这些通路的效果， 在同一实验期内进行不同的试验。目前的建议有三个具体目标：(1) 建立V4中光基因注射后病毒在FEF和LIP中的逆行表达，(Ii)检测 FEF和LIP的皮质通路是否对注意相关神经有不同的贡献 V4中的效应，以及(Iii)测试注意相关增强和注意相关的互补过程 抑制在V4中相互作用。我们将检验中心假设，即FEF主要对目标做出贡献- 通过颗粒上层的连接定向增强V4中的行为相关信息， 而(Ii)在V4中，LIP主要起到目标定向抑制干扰信息的作用 颗粒层下的连接。目前建议将推进我们的总体目标： 理解注意力网络如何塑造我们复杂而动态的环境的视觉处理。

PROJECT SUMMARY: Imagine Times Square in New York City: tall buildings, flashing lights, a swarm of people. This visual scene represents a potential overload of sensory information. To guide behavior, the brain uses a collection of filtering mechanisms that either boosts the processing of behaviorally relevant information or suppresses the processing of distracting information. Impairments in this selective processing of sensory information can have critical consequences for human health. Such consequences are apparent, for example, in visuo-hemineglect associated with stroke, and in some neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). The present proposal specifically focuses on the selective processing of locations in visual space, referred to as spatial attention. A large-scale network of brain regions directs spatial attention, but the specific contributions of each network node to attention-related enhancement and suppression remain largely unknown. Here, we will test whether distinct circuits within the attention network are driving these complementary processes in a well-characterized region of visual cortex, i.e., visual area 4 (i.e., V4). We will specifically investigate functional contributions from two cortical nodes of the attention network in macaques: the frontal eye fields (FEF) in frontal cortex and the lateral intraparietal area (LIP) in parietal cortex. FEF and LIP both contribute to top-down attentional control, based on behavioral goals. To determine whether there are distinct or redundant neural circuits underlying the effects of attention-related enhancement and suppression on visual processing, we will record layer-specific neural activity from V4, while simultaneously using optogenetics (i.e., the use of genetically coded, light-driven ion channels or pumps) to inactivate known corticocortical pathways, either from FEF to V4 or from LIP to V4. The use of optogenetics, in comparison to other causal manipulations (e.g., electrical microstimulation or pharmacological inactivations), will allow us (i) to isolate contributions from specific between-region, corticocortical pathways and (ii) to compare the effects of inactivating these pathways, from either FEF or LIP, on different trials within the same experimental session. The present proposal has three specific aims: (i) to establish the retrograde-only expression of virus in FEF and LIP after optogenetic injections in V4, (ii) to test whether corticocortical pathways from FEF and LIP make distinct contributions to attention-related neural effects in V4, and (iii) to test whether the complementary processes of attention-related enhancement and suppression interact in V4. We will test the Central Hypothesis that FEF primarily contributes to the goal- directed enhancement of behaviorally relevant information in V4 through connectivity in supragranular layers, while (ii) LIP primarily contributes to the goal-directed suppression of distracting information in V4 through connectivity in infragranular layers. The present proposal will advance our overarching objective of understanding how the attention network shapes visual processing of our complex and dynamic environment.