Motion processing with two eyes in three dimensions

描述（由申请人提供）：物体在三维环境中移动，人类显然能够深入感知这种运动。然而，视觉神经科学家并不知道我们的神经系统如何编码视觉世界的这个基本方面。尽管有大量的文献运动和深度知觉，有一个令人惊讶的缺乏知识整合这两个视觉特征，直接表征大脑如何处理的三维方向的移动物体。这项拟议研究的目标是了解灵长类动物大脑中的神经回路如何利用双目信息来表示物体在3D环境中移动的方向。 首先，我们将心理特征的双目线索的三维运动。最近的工作表明，通过深度的运动的感知依赖于两个双目线索，一个是基于随时间变化的差异，一个是基于速度的眼间比较。我们的总体假设是，基于速度的线索是非常重要的三维运动的感知。因此，我们将进行心理物理实验，隔离眼睛特定的运动信号，并将它们相对于基于视觉的信号（并与之相互作用）进行表征。这些实验将解开这些重要感知信息的心理物理构建模块和签名，并改进用于神经成像和电生理研究的视觉显示。 其次，我们将使用神经成像来识别处理3D运动的神经回路。从我们的心理物理学实验中获得刺激和见解，我们将进行功能磁共振成像实验，以可视化人脑中的这种处理。方向选择性自适应协议将被用来表征基于相似性和基于速度的线索及其相互作用，并了解如何（或如果）这些线索被集成到一个单一的（线索独立）表示的三维运动。这些实验还将评估系统的心理物理分析如何直接映射到神经信号。 第三，我们将执行电生理学，以指定潜在的神经计算。在心理物理学和神经影像学的指导下，我们将进行单神经元记录来表征编码3D运动的双眼神经信号。V1中的记录将采用多电极阵列; MT中的记录将采用多四极和单电极清醒准备。这项工作将测试的假设，眼睛特定的运动信号表示在V1的水平，然后集成（由单个神经元）在MT。该3D运动路径可以以较慢的速度暴露，并且因此可以在已知的相同电路中多路复用，以在使用较快的速度评估时提取2D/前平行方向。 公共卫生相关性：真实的世界中的物体在三维空间中移动，人类依靠其深度感知运动的能力来指导适当的行动。对3D运动感知的神经基础的透彻理解将被证明对于涉及在动态三维环境中视觉引导控制机器人或假体设备的生物医学技术的改进是有价值的。

DESCRIPTION (provided by applicant): Objects move through the environment in three dimensions, and humans are clearly capable of perceiving such motion in depth. Visual neuroscientists do not, however, know how our nervous system encodes this fundamental aspect of the visual world. Despite large literatures motion and depth perception, there is a surprising lack of knowledge integrating these two visual features to directly characterize how the brain processes the three-dimensional direction of moving objects. The goal of this proposed research is to understand how neural circuits in the primate brain exploit binocular information to represent the direction of objects moving through a 3D environment. First, we will psychophysically characterize the binocular cues to 3D motion. Recent work suggests that the perception of motion through depth relies on two binocular cues, one based on changing disparities over time, and one based on an inter-ocular comparison of velocities. Our overarching hypothesis is that the velocity-based cue is of great importance for the perception of 3D motion. We will therefore perform psychophysical experiments that isolate eye-specific motion signals and characterize them relative to (and in interaction with) disparity-based signals. These experiments will unpack the psychophysical building blocks and signatures of this important perceptual information, and refine visual displays used for neuroimaging and electrophysiological studies. Second, we will use neuroimaging to identify the neural circuits that process 3D motion. Taking stimuli and insights from our psychophysical experiments, we will perform fMRI experiments to visualize this processing in the human brain. Direction-selective adaptation protocols will be used to characterize both the disparity-based and velocity-based cues and their interactions, and to understand how (or if) these cues are integrated into a single (cue-independent) representation of 3D motion. These experiments will also assess how directly psychophysical assays of the system map on to neural signals. Third, we will perform electrophysiology to specify the underlying neural computations. Guided by the psychophysics and neuroimaging, we will perform single-neuron recordings to characterize the binocular neural signals that encode 3D motion. Recordings in V1 will employ multi-electrode arrays; recordings in MT will employ both multiple-tetrode and single-electrode awake preparations. This work will test the hypothesis that eye-specific motion signals are represented at the level of V1 and are then integrated (by single neurons) in MT. This 3D motion pathway may be exposed at slower speeds, and thus may be multiplexed in the same circuitry known to extract 2D/frontoparallel direction when assessed using faster speeds. PUBLIC HEALTH RELEVANCE: Objects in the real world move through three dimensions, and humans rely on their ability to sense motion in depth in order to guide appropriate actions. A thorough understanding of the neural basis of the perception of 3D motion will prove valuable for the refinement of biomedical technologies involving the visually-guided control of robotic or prosthetic devices in a dynamic three-dimensional environment.