The neural representation and transformation of color in human visual cortex

人类视觉皮层颜色的神经表征和转换

• 批准号: 8461563
• 负责人: DAVID J HEEGER
• 金额: $ 36.58万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8461563
• 关键词: 3-Dimensional; Amblyopia; Appearance; Area; Behavioral; Biological Models; Brain; Cognitive; Color; Color Perception; Complex; Computer Simulation; Data Analyses; Dependence; Discrimination; Elements; Face; Functional Magnetic Resonance Imaging; Human; Illusions; Linear Regressions; Measurement; Measures; Methods; Modality; Modeling; Motion; Motor; Movement; Nature; Neurons; Pattern; Population; Positioning Attribute; Principal Component Analysis; Process; Protocols documentation; Psychophysics; Research; Retinal; Retinal Cone; Retinal Diseases; Sensory; Series; Signal Transduction; Staging; Stimulus; Sum; Techniques; Testing; Translations; Visual; Visual Agnosias; Visual Cortex; Visual Illusions; Visual Perception; Visual impairment; Visual system structure; Weight; Work; base; color category; experience; extrastriate visual cortex; insight; neural patterning; novel; object recognition; relating to nervous system; research study; response; restoration; sensory stimulus; vector; visual information

DESCRIPTION (provided by applicant): The representation of any stimulus can be seen as a unique and distributed pattern of activity in a large population of neurons. These neural representations are thought to undergo a series of transformations across processing stages in visual cortex, and to depend on behavioral demands. The nature of these transformations reveals important insights into the computational mechanisms underlying the formation of behaviorally meaningful neural representations from incoming sensory signals. In this proposal, the focus is on measuring the neural representations and characterizing the transformations for a specific visual modality: color. The representation of color takes on many different forms. For example, humans discriminate between many thousands of hues but use only a handful of discrete color categories. This makes color an ideal candidate to investigate distributed neural representations. The novel empirical and theoretical approaches in the current proposal aim to significantly advance understanding of 1) how the human visual system represents color, 2) how this distributed neural representation is transformed across the hierarchy of visual cortical areas 3) the dependence of these representations on behavioral demands, and 4) the dependence on context. Aim 1 experiments will test the hypothesis that the neural representation of color is transformed as chromatic signals ascend the visual system. Neural color spaces will be derived from functional magnetic resonance imaging (fMRI) measurements, using novel experimental protocols and multivariate data analysis techniques. These neural color spaces will be compared with perceptual color spaces derived from psychophysical measurements of color discrimination and categorization. Aim 1 experiments will also test the hypothesis that neural representations of color depend on behavioral demands. The proposed experiments will distinguish between two specific computational hypotheses: 1) that neural color spaces change for different behavioral tasks, indicating a change in the underlying selectivity and tuning of the neurons, versus 2) a (possibly selective) increase in response gain, with no evidence for a change in the color space. Aim 2 experiments will test the hypothesize that changes in color perception, due to a dramatic visual illusion, are correlated with corresponding shifts in the underlying neural representation, and that the extent of the shift in the neural representation varies between visual areas, depending on the neural color space in each visual area. Ultimately, color provides a model for more complex neural representations (e.g., those underlying face and object recognition, control of movement, etc.) and the findings will provide general insights about distributed neural processes and representations. Consequently, the proposed research will provide information about how the brain transforms an incoming set of signals (of any modality) into a set of meaningful representations that subserve a multitude of tasks.

描述（由申请人提供）：任何刺激的表示都可以被视为大量神经元中独特且分布的活动模式。这些神经表征被认为在视觉皮层的处理阶段经历了一系列的转变，并且取决于行为需求。这些转换的本质揭示了对从传入的感觉信号形成具有行为意义的神经表征的计算机制的重要见解。在该提案中，重点是测量神经表征并表征特定视觉形态（颜色）的转换。颜色的表现有多种不同的形式。例如，人类可以区分数千种色调，但仅使用少数离散的颜色类别。这使得颜色成为研究分布式神经表征的理想选择。 当前提案中的新颖的经验和理论方法旨在显着促进对以下方面的理解：1）人类视觉系统如何表示颜色，2）这种分布式神经表示如何在视觉皮层区域的层次结构中进行转换3）这些表示对行为要求，4) 对环境的依赖。目标 1 实验将检验以下假设：随着彩色信号上升到视觉系统，颜色的神经表征会发生转变。神经色彩空间将使用新颖的实验协议和多变量数据分析技术从功能磁共振成像（fMRI）测量中得出。这些神经色彩空间将与源自颜色辨别和分类的心理物理学测量的感知色彩空间进行比较。目标 1 实验还将检验颜色的神经表征取决于行为需求的假设。所提出的实验将区分两种特定的计算假设：1）神经色彩空间针对不同的行为任务而变化，表明潜在的选择性和调整的变化 神经元，相对于 2）响应增益（可能是选择性的）增加，没有证据表明颜色空间发生变化。目标 2 实验将测试以下假设：由于戏剧性的视觉错觉，颜色感知的变化与底层神经表征的相应变化相关，并且神经表征的变化程度在视觉区域之间有所不同，具体取决于视觉区域每个视觉区域的神经色彩空间。 最终，颜色为更复杂的神经表示（例如，那些底层的面部和物体识别、运动控制等）提供了一个模型，并且研究结果将提供有关分布式神经过程和表示的一般见解。因此，拟议的研究将提供有关大脑如何将一组输入信号（任何形式）转换为一组有意义的表示的信息，以支持多种任务。