Neural mechanisms of color

颜色的神经机制

• 批准号: 9125855
• 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
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9125855
• 关键词: Accounting; 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; Health; 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; Process; Property; Psychometrics; Psychophysics; Research; Role; Sampling; Scheme; Series; Shapes; Signal Transduction; Staging; Stereotyping; Stimulus; Stroke; Temporal Lobe; Testing; Texture; Time; Tissues; Vision; Visual; Visual Perception; Visual impairment; Weight; Work; achromatopsia; base; color category; color processing; experience; habituation; image guided; interstitial; microstimulation; nervous system disorder; neural circuit; neuromechanism; novel; receptive field; relating to nervous system; research study; response; treatment strategy

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(申请人提供)：人们对神经活动、知觉和认知之间的联系知之甚少。这项提议将颜色作为一种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，关于眼睛发出的视锥信号是如何编码并传输到大脑皮层的，人们已经知道了很多。但令人惊讶的是，人们对解码这些信号以产生感知颜色和指导感知决策的机制知之甚少。已经提出了两个相互竞争的解码方案：区间码，它需要具有尖锐色调的细胞群，它们一起包含所有颜色空间，加上赢家通吃的规则；以及种群码，它需要至少两组颜色调整的神经元，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参与其中。其中一个线索来自恒河猴下颞叶皮质(IT)的损伤，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色盲。它是一个广泛的组织区域，牵涉到对象编码的许多方面，而对IT的功能组织知之甚少。没有这些信息，我们几乎不可能知道哪些神经元最有可能参与颜色处理。可能的组织方案包括由独特的专门领域组成的模块模式；分布式处理模式；或由一系列层级组成的混合模式，每个层级包括完整的职能分区域。AIM 1呼吁在警觉的猴子身上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 以测试哪种模型适用于IT组织。目的2概述在fMRI引导下的微电极记录猴子完成颜色任务时与微刺激配对的IT颜色区域，以检验神经活动和感知颜色之间的因果联系，并确定两种解码方案中的哪一种在IT中实施。这项研究将揭示神经回路活动中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，这项工作将建立人和猴子之间的高级区域关系，这对于将猴子用作人类视力和疾病的模型是必要的。