Establishing the Limits of Perceptual Inference for Visual Motion

关于世界的统计学在支配我们的感官知觉方面起着重要的作用。当传入时 感官输入携带有限的信息，例如在黄昏等低对比度条件下，感知似乎 这在很大程度上取决于对不同感官体验概率的隐含假设。更 特别是，当代研究表明，人类视觉运动感知是很好地描述了一个理想的 观察者模型收集有关运动的环境信息，但也假设 环境最有可能是静止的或相对缓慢地移动。实施这一点的理论工作 模型，被称为贝叶斯观测器与“低速先验”，已经成功地解释了许多 不同的感知研究发现了感知运动中的奇怪偏见，并产生了深远的影响。 关于我们如何看待人类的空间视觉。尽管这种低速先验假设很有用，但它使几个 关键的，未经检验的假设：即视觉系统代表一个运动之前，在一个准确的，世界- 坐标系。虽然这对贝叶斯观察者来说是理想的，但它与来自 视觉运动知觉的心理物理学文献。目前还不清楚这种先验在成年人中的灵活性。 面对不断变化的环境条件或刺激。因此，本提案的主要假设是 运动统计（1）的人类表示根据强有力的证据进行更新， 环境统计数据的变化或具体刺激措施统计数据的变化，以及（2）最好的特点是 介于视网膜系统和世界系统之间的坐标系统。拟议的研究将解决 具体目标1中的假设（1），通过测试在暴露于 改变的运动统计很好地解释了更新到慢速之前，概括了整个刺激， 任务该提案将通过在以下条件下估计先验来解决具体目标2中的假设（2）， 分离视网膜和世界运动统计。在每个目标中，将使用以下组合来研究这些问题： 视觉心理物理学和计算建模，正式表示的先验。在一起， 这些目标将解决当前文献中的重大空白， 知觉学习的研究和相对较少的研究解决的方式，其中视觉系统更新 它代表了感官统计学。这些研究将有助于我们了解基本的 将感官证据从外围转换为强大感知的计算。这 奖学金计划包括在世界级研究机构（牛津大学）的详细培训计划。 加州，伯克利）与几位专家在心理物理研究和访问现代视觉显示 技术和计算资源。拟议的研究将利用这些资源， 设计下一代视觉系统中感知推理的模型，该模型植根于物理和 生物限制。

Learned statistics about the world play an important role in dictating our sensory perception. When incoming sensory inputs carry limited information, such as in low-contrast conditions like dusk, percepts appear to be heavily dictated by implicit assumptions about the probability of different sensory experiences. More specifically, contemporary research suggests that human visual motion perception is well-described by an ideal observer model that gathers environmental information about motion, but also assumes that objects in the environment are most likely either stationary or moving relatively slowly. Theoretical work implementing this model, referred to as a Bayesian observer with a "slow speed prior", has successfully explained many disparate perceptual studies that found curious biases in perceived motion, and has had far-reaching influence on how we think about human spatial vision. As useful as this slow speed prior hypothesis is, it makes several critical, untested assumptions: namely that the visual system represents a motion prior in an accurate, world- based coordinate system. While this is ideal for a Bayesian observer, it is at odds with evidence from the psychophysical literature on visual motion perception. It is also unclear how flexible this prior is in adults in the face of changing environmental conditions or stimuli. Thus the overarching hypotheses of this proposal are that human representations of motion statistics (1) are updated in the light of strong evidence for either general changes in environmental statistics or changes in stimulus-specific statistics, and (2) are best characterized by coordinate system that is intermediate between retinal and world systems. The proposed research will address hypothesis (1) in Specific Aim 1 by testing whether changes in perceived visual motion following exposure to altered motion statistics are well-explained by updates to slow speed prior that generalizes across stimuli and tasks. This proposal will address hypothesis (2) in Specific Aim 2 by estimating priors under conditions that dissociate retinal and world motion statistics. In each aim, the questions will be studied using a combination of visual psychophysics and computational modeling that formalizes the representation of the priors. Together, these aims will address the substantial gap in the current literature that is marked by a vast number of perceptual learning studies and relatively few studies addressing the ways in which the visual system updates its representation of sensory statistics. These studies will contribute to our knowledge on the fundamental computations involved in the transformation of sensory evidence from the periphery into robust percepts. This fellowship proposal includes a detailed training plan at a world-class research institution (University of California, Berkeley) with several specialists in psychophysical research and access to modern visual display technology and computational resources. The proposed research will take advantage of these resources to design a next-generation model of perceptual inference in the visual system that is well-rooted in physical and biological constraints.