Construction of invariant shape selectivity in the ventral visual stream

项目摘要 知觉神经科学的一个基本目标是理解 这是我们感知、识别和记忆视觉对象的非凡能力的基础。在人类身上 和非人灵长类动物，这些表征是通过腹侧加工产生的 视觉流，并通过其最高水平的神经元活动模式--猴子--传达 颞下皮质(IT)。腹侧流解决的关键计算问题是它 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、姿势、照明的变化的容差(不变性 杂乱无章。事实上，尽管腹侧流的形状选择性特性已经接收到 尽管研究很多，但我们对构建这种耐受性的机制知之甚少。的目标是 这一建议是对腹侧视觉流如何构建 宽容的(“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：自然获得的时间上的邻接经验是否“指导”了 腹流中耐受性的形成？我们最近发现，IT的容忍度 神经元的形状选择性可以由改变的时间连续性强烈而快速地塑造出来 无人监督的视觉对象体验。在这个目标中，我们将使用一系列密切相关的视觉 经验手法，系统地测试和表征这种可塑性在 位置、大小和姿势容忍度学习。这将说明它在指导成人视觉方面的作用 对象表示，并为长期研究这些功能如何强大奠定了基础 表示法是在早期开发过程中组装的。 在目标2中，我们将采用比较的方法来询问对象信息是如何转换的 两个腹侧流区(V4 vs.IT)？使用相同的猴子、相同的任务和相同的视觉 刺激时，我们会用神经元种群的方法来问：IT的耐受性如何 是否从V4表示更改了表示？V4形状选择性是否保留在IT中 代理律师？视觉表示的稀疏性是否从V4更改为IT？何以 容忍形状选择性实时进化？总而言之，这些实验将向中央 问题：“IT中宽容的对象选择性是如何从早期的视觉表现建立起来的？”，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 并更全面地指导我们对大脑皮层信息转换的理解。

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.