Construction of invariant shape selectivity in the ventral visual stream

项目摘要 感知神经科学的一个基本目标是理解神经元的表征， 是我们感知、识别和记忆视觉物体的非凡能力的基础。在人类中 和非人类灵长类动物，这些表征是通过处理沿着腹侧 视觉流，并通过其最高水平的神经元活动模式传达-猴子 下颞叶皮层（IT）。腹流解决的关键计算问题是， 产生视觉图像的IT神经元表示，传达对对象身份的选择性 和类别，具有对对象位置、大小、姿态、照明 和杂乱。事实上，尽管腹流的形状选择性特性已经得到了 尽管我们做了很多研究，但我们对构建这种耐受性的机制知之甚少。的目标 这一建议是对腹侧视觉流如何构建 宽容（“不变”）的视觉形状选择性，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”了 腹侧流耐受性的形成我们最近发现，对IT的容忍度 神经元的形状选择性可以通过改变时间上的连续性来强烈和快速地塑造， 无监督的视觉体验在这个目标中，我们将使用一系列密切相关的视觉 体验操作，以系统地测试和表征这种可塑性在 位置、大小和姿态公差学习。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 在早期开发期间组装表示。 在目标2中，我们将采用一种比较的方法来询问对象信息如何在 两个腹侧流区（V4与IT）？使用同样的猴子，同样的任务，同样的视觉效果， 刺激，我们将使用神经元群体的方法来问：如何耐受的IT 从V4表示更改表示？IT中是否保留了V4形状选择性 代表？从V4到IT，视觉表示的稀疏性是否发生了变化？如何 容差形状选择性在真实的时间内演化？总之，这些实验将告知一个中央 问题：“IT中的宽容对象选择性是如何从早期的视觉表示中建立起来的？“，以及 这些结果将为腹侧视觉流的计算模型提供强有力的约束 并引导我们更普遍地理解皮层信息转换。

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.