Allocation and Control of Visual Attention

描述（由申请人提供）：选择性注意是感觉处理的关键组成部分。大量的信息冲击到感觉上皮细胞，很可能超出了我们大脑的计算能力。在进化史上出现了几种策略，通过促进选择最显著的环境刺激来减少感觉处理的计算需求。其中一些策略，如在皮层下消除冗余信息，似乎是连续发生的，没有有意识的努力。其他的策略，如视觉或听觉中央凹对显著特征的仔细定位，依赖于一个封闭的感觉-运动回路，经常受到有意识的思维和动态变化的行为目标的高度影响。选择性注意可以将有限的计算资源集中在输入刺激的子集上，从而加速或增强对相关刺激的行为反应。在过去的二十年里，这个心理学框架已经稳步扩展到神经元水平，因为神经科学家越来越意识到皮层，甚至是皮层下神经元表现出一种惊人的能力，可以动态重组以支持不断变化的行为目标。在神经元水平上，选择性注意代表了另一种策略，通过衰减不相关和/或放大相关信息来控制大量流入的感觉信息。本研究探讨了选择性注意对层外视觉皮层神经元选择性的影响。具体来说，本文描述的实验旨在描述在视觉搜索过程中，当选择性注意被部署时，负责脑外区V4视觉敏感性和特征选择性动态变化的皮质回路。为了研究这个问题，我们将记录和描述清醒的灵长类动物在执行注意力要求的视觉搜索任务时的神经元活动。在具体目标1中，我们将研究基于特征的注意如何改变V4神经元的偏好刺激，以支持改进的目标检测。在目标2中，我们将研究在面对搜索目标确切空间位置的不确定性增加时，空间注意力的分配是如何分布的。在这两个目标中，我们将结合多种方法，即单个神经元记录和局部场分析，以更全面地了解选择性注意如何在皮层神经元和皮层微回路水平上运作。拟议的研究将促进我们对“集中注意力”如何提高在困难任务中的表现的理解。在这些实验中，我们将研究视觉系统在视觉搜索过程中如何重新配置注意力。在一些越来越常见的临床疾病中，例如自闭症和注意缺陷多动障碍，人们认为潜在的注意力部署的神经元机制严重受损，经常直接导致适应不良行为。开发更好的注意力分配和控制模型将促进我们对这些疾病的理解和治疗潜力。

DESCRIPTION (provided by applicant): Selective attention represents a key component of sensory processing. The vast amount of information impinging on the sensory epithelium is likely to routinely exceed the computational capacities of our brains. Several strategies have appeared in evolutionary history to reduce the computational demands of sensory processing by facilitating selection of the most salient environmental stimuli. Some of these strategies, like the elimination of redundant information at sub-cortical levels, seems to occur continuously and without conscious effort. Other strategies, like careful orientation of the visual or acoustic fovea towards salient features, depends on a closed sensory-motor loop and are often highly influenced by conscious thought and dynamically changing behavioral goals. Selective attention can focus limited computational resources on subsets of incoming stimuli, thereby accelerating or enhancing behavioral responses to relevant stimuli. Over the last twenty years, this psychological framework has been steadily extended to the neuronal level as neuroscientists have become increasingly aware that cortical, and even sub-cortical, neurons exhibit a surprising ability to dynamically reorganize in support of changing behavioral goals. Selective attention, at the neuronal level, represents another strategy for controlling the large volume of inflowing sensory information by attenuating irrelevant and/or amplifying relevant information. This proposal explores the effects of selective attention on neuronal selectivity in extrastriate visual cortex. Specifically, the experiments described here are aimed at characterizing the cortical circuitry responsible for dynamic changes in visual sensitivity and feature selectivity in extrastriate area V4 when selective attention is deployed during visual search. To investigate this question, we will record and characterize neuronal activity in awake primates performing attentionally demanding visual search tasks. In Specific Aim 1 we will investigate how feature-based attention can alter the preferred stimuli of V4 neurons in support of improved target detection. In Aim 2 we will investigate how the allocation of spatial attention is distributed in the face of increasing uncertainty about the exact spatial position of a search target. In both of these Aims we will combine multiple approaches, namely single neuron recordings and local field analysis to generate a more complete picture of how selective attention operates at the level of the cortical neuron and cortical microcircuit. PUBLIC HEALTH RELEVANCE The proposed research will advance our understanding of how "paying attention" improves performance on difficult tasks. In these experiments we will investigate how the visual system reconfigures when attention is deployed during visual search. In several increasingly common clinical conditions, for example autism and attention deficit hyperactivity disorder, the neuronal mechanisms underlying attentional deployment are thought to be substantially impaired, frequently leading directly to maladaptive behavior. Developing better models of attentional allocation and control will advance our understanding and the potential for treatment of these conditions.