Correlates of perceived size in V1 neurons

描述（由申请人提供）：该项目的目标是使用行为和单单元记录技术来理解三维 (3D) 上下文在对象大小的神经处理中的作用。估计物体的大小凸显了视觉中的一个基本计算问题：视网膜图像固有的模糊性。对于任何给定的视网膜图像，物体大小和观看距离的组合有无数种，可以产生该图像。一个基本的挑战是了解距离信息（未在视网膜图像中明确表示）如何与视网膜尺寸信息相结合，以实现物体尺寸的准确且稳定的表示。该提案的总体框架是在视觉系统的早期阶段将距离信息与视网膜尺寸信息相结合。 来自人类行为、功能磁共振成像和 ERP 实验的综合证据表明，物体大小由初级视觉皮层表示。这些结果与初级视觉皮层被动反射视网膜上的刺激不一致，而是表明与 3D 场景解释相关的高级信号可能会反馈到初级视觉皮层，以调整分配用于表示视觉对象的组织量。为了扩展这些发现，我们提出的实验使用心理物理测量和单神经元电生理记录在动物模型中追求这些结果。提出了两个具体目标：1）单单元记录，以研究单个视觉皮层神经元感受野结构随 3D 环境变化的变化；2）在特定目标 1 中使用的同一动物模型中对尺寸错觉进行心理物理学测量。这些具体目标将共同揭示尺寸感知的过程，这对于与 3D 世界交互至关重要，并将在人类和非人类受试者的视觉研究之间架起一座桥梁。 公共卫生相关性：该项目的相关性在于我们将进一步了解大脑如何构建对环境的视觉感知。这个过程是到达眼睛的光信号与我们关于环境结构的内置隐性知识之间的复杂相互作用。这种理解对于确定视觉系统如何发育以及寻找针对脑损伤或疾病引起的视觉障碍的潜在治疗方法至关重要。

DESCRIPTION (provided by applicant): The goal of this project is to use behavioral and single-unit recording techniques to understand the role of three-dimensional (3D) context in the neural processing of object size. Estimating the size of an object highlights a fundamental computational problem in vision: the inherent ambiguity in the retinal image. For any given retinal image there are an infinite number of combinations of object sizes and viewing distances that could give rise to that image. A fundamental challenge is to understand how distance information - which is not explicitly represented in the retinal image - is combined with retinal size information to achieve an accurate and stable representation of object size. The overarching framework of this proposal is that distance information is combined with retinal size information in early stages of the visual system. Convergent evidence from behavioral, fMRI, and ERP experiments in humans have shown that object size is represented in the primary visual cortex. These results are inconsistent with the primary visual cortex passively reflecting the stimulus on the retina, but rather suggest that high-level signals related to 3D scene interpretation may be fed back to primary visual cortex to adjust the amount of tissue allocated to represent visual objects. To extend these findings, our proposed experiments pursue these results in an animal model using psychophysical measurements and single-neuron electrophysiological recordings. Two specific aims are proposed: 1) single-unit recording to investigate the changes in receptive field structure of individual visual cortical neurons as a function of 3D context and 2) psychophysical measurements of size illusions in the same animal model used in specific aim 1. Together these specific aims will shed light on the processes that underlie size perception, which are critical for interacting with a 3D world, and will provide a bridge between vision studies in human and non-human subjects. PUBLIC HEALTH RELEVANCE: The relevance of this project is that we will gain further understanding into how the brain constructs visual perceptions of the environment. This process is a complex interaction between the light signal that arrives at the eye and our built- in, implicit knowledge about the structure of the environment. This understanding is essential for identifying how the visual system develops and for finding potential treatments for visual impairments in response to brain injury or disease.