Population codes and sensory discrimination

人口代码和感官歧视

• 批准号: 10709774
• 负责人: DARIO L RINGACH
• 金额: $ 41.52万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-15 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10709774
• 关键词: Population; codes; sensory; discrimination

Project Summary / Abstract How do cortical populations represent sensory input and support perceptual decision making? It has long been known that the responses of individual neurons to the repeated presentation of a stimulus are highly variable. Nonetheless, the pattern of activity across a population encodes enough information to support precise perceptual decisions. This implies that hidden in the distribution of population responses there are invariant features, yet to be identified, which robustly encode the sensory stimulus from one trial to the next. Here we propose to mathematically model the conditional distribution of the population response given a stimulus and to uncover the invariant features that support the reliable discrimination of sensory stimuli. Surprisingly, preliminary data reveal that the distribution of population responses to a fixed stimulus is star- shaped — in any one trial, the population vector can point in one among a finite set of directions. The directions are highly invariant across trials, while the amplitude of the responses is variable. Based on these observations we hypothesize that cortical coding is a one-to-many correspondence. This idea represents a major departure from the prevailing view of cortical coding as a one-to-one map between a stimulus and a population direction. We propose to study star-shaped distributions and their role in the encoding of sensory information with the following three Aims: (a) measure population responses to the repeated presentation of a stimulus and test the hypothesis the structure is well-described by star-shaped distributions, (b) test a mathematical model linking the direction of population responses evoked in indiviudal trials to behavioral choice in a discrimination task, (c) establish if star-shaped distributions are generated in the cortex or inherited from thalamic input. The proposed studies are significant because they challenge the dominant view that cortical coding implements a one-to-one map. We introduce an innovative framework to study and understand the structure of cortical variability that generalizes prior approaches, yielding predictive models that link population activity to behavior. Altogether, the proposed studies will significantly advance our understanding of cortical coding and function.

项目总结/摘要 皮质群如何代表感觉输入并支持知觉决策？人们早就 已知单个神经元对重复呈现的刺激的反应是高度可变的。 尽管如此，整个种群的活动模式编码了足够的信息来支持精确的 知觉决定这意味着在群体反应的分布中隐藏着不变的 特征，尚未被识别，其从一个试验到下一个试验鲁棒地编码感官刺激。这里我们 建议对给定刺激的群体响应的条件分布进行数学建模， 揭示支持感官刺激的可靠区分的不变特征。 令人惊讶的是，初步数据显示，对固定刺激的群体反应分布是星星- 形状-在任何一次试验中，种群向量都可以指向有限方向集中的一个方向。的方向 在试验中高度不变，而响应的幅度是可变的。基于这些观察 我们假设皮层编码是一对多的对应关系。这个想法代表了一个重大的偏离 从流行的观点来看，皮层编码是刺激和群体方向之间的一对一映射。 我们建议研究星形分布及其在感官信息编码中的作用， 以下三个目的：（a）测量人口对重复呈现刺激的反应，并测试 假设该结构由星形分布很好地描述，（B）测试连接该结构的数学模型。 在个体试验中诱发的群体反应方向对辨别任务中的行为选择，（c） 确定星形分布是在皮层中产生的还是从丘脑输入中继承的。 这项研究意义重大，因为它们挑战了大脑皮层编码 一对一的地图我们引入了一个创新的框架来研究和理解皮层的结构， 变异性概括了先前的方法，产生了将人口活动与行为联系起来的预测模型。 总而言之，这些研究将大大促进我们对皮层编码和功能的理解。