Probing the role of feature dimension maps in visual cognition

项目总结 当在灌木丛中寻找红色瓢虫时，我们的注意力可能会被树丛中的红色有效地引导 绿叶。相反，如果我们的目标是找到一只绿色的毛毛虫，那么同样的红色就需要被忽略， 取而代之的是，一片移动的叶子应该指引我们的寻找。搜索对象涉及到复杂的相互作用 独特的环境特征，吸引我们的注意力(例如，瓢虫)和我们当前的任务 目标(例如，寻找与绿色毛毛虫相关的运动)。目前尚不清楚不同的大脑 区域有助于基于不同类型的环境特征的视觉注意的引导， 以及这些大脑区域的激活模式如何受到我们的行为目标的影响。我们的长期目标是 了解分布式神经处理系统如何支持灵活视觉的原理 认知力。我们的总体目标，也是我们追求长期目标的下一步，是确定如何达到- 向下目标和自下而上的刺激属性共同塑造了整个功能选择性大脑的激活模式 地区。我们的中心假设是支持注意力选择的核心计算--自下而上 增强显著位置和自上而下地增强相关位置或刺激维度- 发生在在特征选择性皮质区域实例化的划分维度图的级别，以及 这些调制被聚合到一个统一的优先级映射中，以指导行为。建议的理由是 研究表明，一旦我们确定了注意力选择如何调节健康参与者的维度图， 我们可以建立改进的诊断和治疗技术来理解和治疗注意力障碍 控制力。这一假设将通过三个目标进行检验：(1)分析自下而上的刺激显著如何影响 在维度图和优先级图中的刺激表示；(2)表征顶层的独立影响。 向下注意选择维度图内的激活轮廓，以及(3)确立神经的作用 维度图在视觉搜索任务中引导注意。在所有目标中，我们将应用基于模型的 神经成像分析用于测量特征选择性视网膜定位脑区的刺激表征 用功能磁共振成像。在目标1中，参与者将执行一项注视任务，而我们将呈现不同类型的刺激进行测量 与不同特征的刺激显著相关的反应。在目标2中，参与者将有选择地参加 当我们操纵刺激显示的属性时，定义刺激的几个特征值之一。在AIM 3，参与者将执行一项要求很高的视觉搜索任务，而我们则操纵任务和刺激的各个方面 展示。总体而言，该项目将生成数据，以确定维度图在引导视觉注意力方面的作用。 该项目具有创新性，因为它使用基于模型的神经成像分析来表征空间地图 在苛刻的认知行为中由特征选择的大脑区域携带，因为它测试了一个关键方面 一个重要的理论框架。这个项目意义重大，因为它将导致对 不同的大脑区域如何协作，结合刺激和任务相关的因素来引导视觉注意力。

PROJECT SUMMARY When looking for a red ladybug in a bush, our attention may be efficiently guided by the red color among the green leaves. If, instead, finding a green caterpillar is our goal, the same red color would need to be ignored, and instead a moving leaf should guide our search. Searching for an object involves a complex interplay between features of the environment that are unique and capture our attention (e.g., the ladybug) and our current task goals (e.g., look for the movement associated with a green caterpillar). It remains unknown how different brain regions contribute to the guidance of visual attention based on different types of features of the environment, and how activation patterns in these brain regions are impacted by our behavioral goals. Our long-term goal is to understand the principles governing how distributed neural processing systems support flexible visual cognition. Our overall objective, which is the next step in pursuit of our long-term goal, is to ascertain how top- down goals and bottom-up stimulus properties jointly mold activation patterns across feature-selective brain regions. Our central hypothesis is that the core computations supporting attentional selection – bottom-up enhancement of salient locations and top-down enhancement of relevant locations or stimulus dimensions – occur at the level of compartmentalized dimension maps instantiated in feature-selective cortical areas, and these modulations are aggregated into a unified priority map to guide behavior. The rationale for the proposed research is that, once we establish how attentional selection modulates dimension maps in healthy participants, we can build improved diagnostic and therapeutic techniques to understand and treat disorders of attentional control. This hypothesis will be tested across 3 Aims: (1) assay how bottom-up stimulus salience impacts stimulus representations in dimension maps and priority maps; (2) characterize the independent impact of top- down attentional selection on activation profiles within dimension maps, and (3) establish the role of neural dimension maps in guiding attention during visual search tasks. Across all Aims, we will apply model-based neuroimaging analyses to assay stimulus representations in feature-selective retinotopic brain regions measured with fMRI. In Aim 1, participants will perform a fixation task while we present different types of stimuli to measure responses associated with stimulus salience in different features. In Aim 2, participants will selectively attend to one of several feature values defining a stimulus while we manipulate properties of the stimulus display. In Aim 3, participants will perform a demanding visual search task while we manipulate aspects of the task and stimulus display. Overall, this project will generate data to determine the role of dimension maps in guiding visual attention. This project is innovative because it uses model-based neuroimaging analyses to characterize spatial maps carried by feature-selective brain regions during demanding cognitive behavior, and because it tests a key aspect of an important theoretical framework. This project is significant because it will lead to a new understanding of how disparate brain regions collaborate to incorporate stimulus- and task-related factors to guide visual attention.