Correlates of perceived size in V1 neurons

这个项目的目标是使用行为和单单元记录 技术，以了解三维（3D）的背景下，在神经的作用， 对象大小的处理。估计对象的大小突出了 视觉中的基本计算问题：视网膜中固有的模糊性 形象对于任何给定的视网膜图像， 物体的大小和观察距离，这些都能产生这样的图像。一 一个根本的挑战是要了解距离信息--这不是 在视网膜图像中明确表示-与视网膜大小相结合 信息，以实现对象大小的准确和稳定的表示。的 该建议的总体框架是， 在视觉系统的早期阶段，视网膜的大小信息。 来自行为，功能磁共振成像和ERP实验的收敛证据， 人类已经表明，物体的大小是在初级视觉皮层中表示的。 这些结果与初级视觉皮层被动地反映 视网膜上的刺激，而是表明与3D相关的高水平信号 场景解释可以被反馈到初级视觉皮层以调整 用于表示视觉对象的组织量。为了扩展这些发现， 我们提出的实验在动物模型中追求这些结果，使用 心理物理测量和单神经元电生理 录音.提出了两个具体目标：1）单一单位记录， 观察个体视皮层感受野结构的变化 神经元作为3D上下文的函数，以及2）大小的心理物理测量 在特定目标1中使用的相同动物模型中的错觉。综合这些 具体的目标将揭示的过程，基础规模的看法， 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。

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.