Neural mechanisms of color

颜色的神经机制

基本信息

批准号：
9335851
负责人：
Mehrdad Jazayeri
金额：
$ 39万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9335851
关键词：
Afterimage Animals Anterior Appearance Area Automobile Driving Biological Biological Models Blindness Brain Brain region Bypass Cells Cerebral cortex Code Cognition Color Color blindness Complement Complex Cone Coupled Data Diagnosis Discrimination Disease Etiology Eye Face Frequencies Functional Magnetic Resonance Imaging Hospitals Human Hybrids Impaired cognition Inferior Knowledge Lesion Link Location Macaca mulatta Measures Mediating Memory Mental disorders Microelectrodes Modeling Monkeys Nature Neurons Pattern Perception Population Probability Property Psychometrics Psychophysics Research Role Sampling Scheme Series Shapes Signal Transduction Stereotyping Stimulus Stroke Temporal Lobe Testing Texture Time Tissues Vision Visual Visual Perception Visual impairment Work achromatopsia base color category color processing experience experimental study habituation image guided interstitial microstimulation nervous system disorder neural circuit neuromechanism novel public health relevance receptive field relating to nervous system response treatment strategy

项目摘要

DESCRIPTION (provided by applicant): The links between neural activity, perception and cognition are poorly understood. This proposal advances color as a model system to fill these gaps in knowledge. Color is an essential feature of visual experience, and much is known about how cone signals from the eye are encoded and transmitted to the cortex. But surprisingly little is known about the mechanisms that decode these signals to bring about perceived colors and guide perceptual decisions. Two competing decoding schemes have been proposed: an interval code, which requires a population of cells with sharp chromatic tuning that together encompass all color space, coupled with a winner- take-all rule; and a population code, which needs at minimum two groups of color-tuned neurons, coupled with a weighted-average rule. It is unclear which groups of neurons within the cerebral cortex are involved. One hint comes from lesions of inferior temporal cortex (IT) in rhesus monkeys, which cause profound color blindness similar to the achromatopsia that accompanies certain cerebral strokes in humans. IT is an expansive region of tissue implicated in many aspects of object coding, and the functional organization of IT is poorly understood. Without this information, it is almost impossible to know which neurons are the most likely to be contributing to color processing. Possible organizational schemes include a modular model comprising uniquely specialized areas; a distributed-processing model; or a hybrid model, consisting of a series of hierarchical stages, each comprising a full complement of functional subregions. Aim 1 calls for a battery of functional magnetic resonance imaging (fMRI) experiments in alert monkey that will determine the distribution of color-coding regions in IT, their functional connectivity and relationship to other functionally defined regions to test which model accounts for the organization of IT. Aim 2 outlines fMRI-guided microelectrode recordings of IT color regions paired with microstimulation while monkeys perform color tasks, to test the causal link between neural activity and perceived color, and to determine which of the two decoding schemes, interval or population, is implemented in IT. The research will uncover principles by which perception and cognition emerge from the activity of neural circuits. This information is required to understand the etiology, diagnosis, and treatment of mental illnesses and strokes that impair cognition and perception. Moreover, the work will establish the relationship of higher-order areas between humans and monkeys, which is necessary in order to use monkeys as models of human vision and disease.

描述（由申请人提供）：人们对神经活动、感知和认知之间的联系知之甚少。该提案提出将颜色作为模型系统来填补这些知识空白。颜色是视觉体验的一个基本特征，人们对来自眼睛的视锥细胞信号如何编码并传输到皮层的了解很多。但令人惊讶的是，人们对解码这些信号以产生感知颜色并指导感知决策的机制知之甚少。已经提出了两种相互竞争的解码方案：间隔码，它需要一组具有尖锐色彩调谐的单元，这些单元一起包含所有颜色空间，并结合赢者通吃的规则；和一个群体代码，它至少需要两组颜色调整的神经元，再加上加权平均规则。目前尚不清楚大脑皮层内的哪些神经元群参与其中。一个线索来自于恒河猴的下颞叶皮层（IT）损伤，这种损伤会导致严重的色盲，类似于人类某些脑中风所伴随的全色盲。 IT 是一个广阔的组织区域，涉及对象编码的许多方面，而人们对 IT 的功能组织知之甚少。如果没有这些信息，几乎不可能知道哪些神经元最有可能对颜色处理做出贡献。可能的组织方案包括由独特的专业领域组成的模块化模型；分布式处理模型；或混合模型，由一系列分层阶段组成，每个阶段包含完整的功能子区域。目标 1 要求在警觉猴子中进行一系列功能磁共振成像 (fMRI) 实验，以确定 IT 中颜色编码区域的分布、它们的功能连接性以及与其他功能定义区域的关系测试 IT 组织的模型。目标 2 概述了当猴子执行颜色任务时，功能磁共振成像引导的 IT 颜色区域的微电极记录与微刺激配对，以测试神经活动和感知颜色之间的因果关系，并确定两种解码方案（间隔或群体）中的哪一个被实施。它。该研究将揭示神经回路活动产生感知和认知的原理。这些信息是了解损害认知和知觉的精神疾病和中风的病因、诊断和治疗所必需的。此外，这项工作将建立人类和猴子之间的高阶区域的关系，这对于使用猴子作为人类视觉和疾病的模型是必要的。