Neural correlates of 3D visual orientation

描述（由申请人提供）：我们可以看到三维（3D）的东西，因为视觉系统从投射到视网膜上的物体的二维图像重建物体的3D配置。先前的研究已经描述了顶叶损伤后3D双眼视觉和结构性失用的丧失，尽管这种影响的神经生理学仍然知之甚少。许多研究的特点是双眼视差处理的神经基础，虽然很少有处理的三维表面方向的表示。拟议的研究使用多方面的方法，并承诺提供重要的见解顶叶皮层在3D视觉和视觉方向的恒定性的作用。具体来说，在拟议的研究中，我们检查神经的选择性的3D表面取向，提出了不同的3D方向的平面刺激，而神经元的反应记录从尾侧顶内区（CIP），前顶内区（AIP）和区域V3 a的猕猴。我们采用多方面的方法，结合神经记录，行为，群体解码和化学灭活。这些区域的神经元被调整为在表面方向上的倾斜操作，如由双眼视差或线性透视和纹理梯度所定义的。在这里，我们测试V3 a/CIP/AIP神经元的调谐是否代表倾斜和倾斜的所有组合，以及倾斜和倾斜调谐曲线是否独立于定义的线索，刺激位置在frontoparallel平面和深度。此外，我们还探讨了该区域在视觉定向恒定性中的作用，即，当头部/身体取向在世界上改变时，保持场景的感知作为整体稳定取向的能力。我们假设，通过结合部分调谐曲线移位和增益变化，CIP和AIP中的种群活动实现了视觉定向恒定性。这将允许在世界坐标中表示对象的3D方向，这是实现我们与环境的许多交互所必需的属性。此外，我们将使用Fisher信息分析来计算人口阈值如何作为倾斜和倾斜参考方向的函数而变化。我们假设CIP/AIP神经元的特性可以预测行为阈值及其对参考方向的依赖性。最后，我们将直接测试的因果关系的作用，这些领域中的每一个倾斜歧视首先记录广告，然后操纵神经活动，而猕猴执行一个罚款倾斜歧视任务。神经放电率将使用信号检测理论进行分析，神经元敏感性将被 与行为敏感性相比。使用相同的数据集，我们还将计算“选择概率”，以确定神经元反应的试验间变异性是否与感知选择的变异性相关。然后，我们将探讨在这些领域的神经元和3D表面取向知觉之间的因果关系，采用可逆失活。总之，这些研究构成了一个国家的最先进的多方面的方法，并将提供一个重要的测试， 这个回路有助于3D视觉的假设。

DESCRIPTION (provided by applicant): We can see things in three dimensions (3D) because the visual system reconstructs the 3D configuration of objects from their two-dimensional images projected onto the retina. Previous studies have described loss of 3D binocular vision and constructional apraxia after parietal lesions, although the neurophysiology of this effect remains poorly understood. Many studies have characterized the neural basis of binocular disparity processing, although few have dealt with the representation of 3D surface orientation. The proposed studies use a multi-faceted approach and promise to provide important insights into the role of the parietal cortex in 3D vision and visual orientation constancy. Specifically, i the proposed studies we examine neural selectivity for 3D surface orientation by presenting planar stimuli with different 3D orientations while neuronal responses are recorded from the caudal intraparietal area (CIP), anterior intraparietal area (AIP) and area V3a of macaque monkeys. We employ a multi-faceted approach, combining neural recordings, behavior, population decoding & chemical inactivation. Neurons in these areas are tuned to tilt manipulations in surface orientation, as defined by either binocular disparity or linear perspective and texture gradients. Here we test whether tuning of V3a/CIP/AIP neurons represents all combinations of tilt and slant, as well as whether tilt and slant tuning curves are independent of the defining cue, stimulus position in the frontoparallel plane and in depth. Furthermore, we also explore the role of this area in visual orientation constancy, i.e., the abiliy to maintain the percept of the scene as a whole stably oriented as head/body orientation changes in the world. We hypothesize that, through a combination of partial tuning curve shifts and gain changes, population activity in CIP and AIP achieves visual orientation constancy. This would allow a representation of the 3D orientation of objects in world coordinates, a property that is necessary to implement many of our interactions with the environment. In addition, we will use Fisher information analyses to compute how population thresholds vary as a function of tilt and slant reference orientation. We hypothesize that the properties of CIP/AIP neurons can predict behavioral thresholds and their dependence on reference orientation. Finally, we will directly test for a causal role of each of these areas in slant discrimination by first recording ad then manipulating neural activity while macaques perform a fine slant discrimination task. Neural firing rates will be analyzed using signal detection theory and neuronal sensitivity will be compared to behavioral sensitivity. Using the same dataset, we will also compute 'choice probabilities' to establish whether trial-to-trial variability in neuronal responses is correlated ith variability in perceptual choices. We will then probe for causal links between neurons in these areas and 3D surface orientation perception by employing reversible inactivation. Together, these studies constitute a state-of-the-art multi-faceted approach and will provide a vital test of the hypothesis that this circuit contributes to 3D vision.