Construction of invariant shape selectivity in the ventral visual stream

腹侧视觉流中不变形状选择性的构建

基本信息

批准号：
8204991
负责人：
James J DiCarlo
金额：
$ 39.03万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-04-01 至 2014-11-30
项目状态：
已结题

项目摘要

Project Summary A fundamental goal of perceptual neuroscience is to understand the neuronal representations that underlie our remarkable ability to perceive, recognize, and remember visual objects. In humans and non-human primates, these representations are produced by processing along the ventral visual stream, and conveyed by patterns of neuronal activity in its highest level -- the monkey inferior temporal cortex (IT). The key computational problem the ventral stream solves is that it produces an IT neuronal representation of visual images that conveys selectivity for object identity and category, with tolerance ("invariance") to changes in object position, size, pose, illumination and clutter. Indeed, although the shape selectivity properties of the ventral stream have received much study, we know very little about the mechanisms that construct that tolerance. The goal of this proposal is a mechanistic understanding of how the ventral visual stream constructs the tolerant ("invariant") visual shape selectivity that underlies our object recognition abilities. In Aim 1 we ask: does naturally-acquired temporally contiguous experience "instruct" the formation of tolerance in the ventral stream? We have recently discovered that the tolerance of IT neuronal shape selectivity can be strongly and rapidly sculpted by altered temporal contiguity of unsupervised visual object experience. In this aim, we will use a series of closely-related visual experience manipulations to systematically test and characterize the role of this plasticity in position, size, and pose tolerance learning. This will illuminate its role in instructing adult visual object representation, and set the stage for longer-term studies of how these powerful representations are assembled during early development. In Aim 2 we will take a comparative approach to ask how object information is transformed across two ventral stream areas (V4 vs. IT)? Using the same monkeys, same task, and same visual stimuli, we will use neuronal population methods to ask: How is the tolerance of the IT representation changed from the V4 representation? Is V4 shape selectivity preserved in the IT representation? Does the sparseness of visual representation change from V4 to IT? How does tolerant shape selectivity evolve in real time? Together, these experiments will inform a central question: "How is the tolerant object selectivity in IT built from earlier visual representation?", and the results will provide strong constraints on computational models of the ventral visual stream and guide our understanding of cortical information transformation more generally.

项目概要感知神经科学的一个基本目标是理解神经元表征这是我们感知、识别和记忆视觉对象的卓越能力的基础。在人类中和非人类灵长类动物，这些表征是通过沿着腹侧处理产生的视觉流，并通过最高级别的神经元活动模式（猴子）来传达下颞叶皮层（IT）。腹侧流解决的关键计算问题是生成视觉图像的 IT 神经元表示，传达对象身份的选择性和类别，对对象位置、大小、姿势、照明的变化具有容差（“不变性”）和混乱。事实上，尽管腹侧流的形状选择性特性已经受到经过大量研究，我们对构建这种耐受性的机制知之甚少。目标是这个提议是对腹侧视觉流如何构建宽容（“不变”）视觉形状选择性是我们物体识别能力的基础。在目标 1 中，我们问：自然获得的时间连续经验是否“指导” 腹侧流中耐受性的形成？我们最近发现IT的容忍度神经元形状选择性可以通过改变神经元的时间连续性来强烈而快速地塑造无监督的视觉对象体验。为了这个目标，我们将使用一系列密切相关的视觉经验操纵系统地测试和表征这种可塑性的作用位置、大小和姿势容差学习。这将阐明它在指导成人视觉方面的作用对象表示，并为长期研究这些强大的表征是在早期开发过程中组装的。在目标 2 中，我们将采用比较方法来询问对象信息如何在不同环境之间进行转换两个腹侧流区域（V4 与 IT）？使用相同的猴子、相同的任务和相同的视觉效果刺激，我们将使用神经元群体方法来询问：IT的耐受性如何 V4 表示法发生了变化吗？ IT 中是否保留了 V4 形状选择性表示？从 V4 到 IT，视觉表示的稀疏性是否发生变化？怎么样宽容的形状选择性实时演变？总之，这些实验将为中央提供信息问题：“IT 中的宽容对象选择性是如何从早期的视觉表示中构建出来的？”，以及结果将为腹侧视觉流的计算模型提供强有力的约束并指导我们更普遍地理解皮质信息转换。