PROCESSING STREAMS IN EARLY VISION

描述(调查人员摘要)：最近的证据表明 视觉处理的早期阶段可以分为几个平行的阶段 专门用于分析不同视觉效果的流 属性。在这里提出的研究将调查路由 使用五种刺激通过这些早期处理流传递信息 媒体：亮度、颜色、纹理、立体声和运动。尤其是， 研究人员对这些早期的相对贡献感兴趣 流到最终确定刺激形状特征(具体地 大小和方向)、运动和深度，以及是否测量 形状、运动和立体声多次出现(每次重复 路径)或仅在共同表示中一次。相反的刺激， 归纳和适应范式将被用来评估 对每种介质的分析的独立性。初步实验 表明对二维形状特征的类似分析实际上是重复的 对于每种媒介。这种重复分析的一个原因可能是 汇集多个介质的信息可以提高等高线的精度 本地化，特别是当亮度信息不可靠时。一个 第二个原因是使用相似的代码或图像格式 代表权将为他们随后的融合提供便利。另一方面 另一方面，另一项试点实验表明，多个、特定于中型的 不会对运动进行分析。情况可能类似于 双眼视差的分析。 如果独立于其他介质来分析介质，例如，取向， 调查员还将在其中寻找编码的独立性 5~6成熟。例如，如果颜色定义的边框的方向为 中定义的边框的方向独立分析 媒体，可能是负责的机制对 任何颜色边框的方向，无论涉及哪种颜色-- 是，它们可能是特定于颜色的，但对特定颜色没有选择性 (无独立编码)。或者，它们可能都对颜色有选择性 以及定向选择性(独立性)。同样的对立 将使用上述归纳和适应范例来评估 对一种媒介中不同价值的分析的独立性。这个 这些研究的结果将与一组相应的 对连词进行视觉搜索的实验。这些视觉搜索任务 将连接相同的值(例如，颜色和方向、颜色和运动) 与在相反的诱导和适应实验中测试的那些相同。这个 预测是，在相反的适应实验中的独立性将 与连词任务中缓慢的、连续的搜索相关。这个 解释在于分心物组的异质性。 除了正常观察者的心理物理任务外， 调查人员建议对已知丢失的患者进行测试(尤其是， 皮质色盲)来验证信息的路由。哪里 在数据的支持下，调查人员应将这些测试扩展为 测量不同视觉通路的相对功能，可能是 对特定疾病的诊断。

DESCRIPTION (Investigator's Abstract): Recent evidence indicates that the early stages in visual processing may be broken into several parallel streams that are specialized for the analysis of different visual attributes. The research proposed here will investigate the routing of information through these early processing streams using five stimulus media: luminance, color, texture, stereo and motion. In particular, the investigator is interested in the relative contributions of these early streams to the final determination of stimulus shape features (specifically size and orientation), motion and depth, and whether the measurement of shape, motion, and stereo emerges several times (repeated within each pathway) or only once in a common representation. Opposed stimuli, induction and adaptation paradigms will be used to evaluate the degree of independence of the analyses for each medium. Preliminary experiments suggest that a similar analysis of 2-D shape features is actually repeated for each medium. One reason for this duplication of analyses may be that pooling information from several media can improve the accuracy of contour localization particularly when luminance information is unreliable. A second reason is that using similar codes or image formats for each representation will facilitate their subsequent integration. On the other hand, another pilot experiment suggests that multiple, medium-specific analyses do not occur for motion. The situation may be similar for analyses of binocular disparity. If a medium is analyzed independently of other media for, say, orientation, the investigator will also look for independence of coding within that medium. For example, if the orientation of color-defined borders is analyzed independently of the orientation of borders defined in other media, it may be that the mechanisms responsible are selective for the orientation of any color border no matter which colors are involved -- that is, they may be specific to color but not selective for particular colors (no independent coding). Alternatively, they might be both color-selective as well as orientation-selective (independence). The same opposing induction and adaptation paradigms mentioned above will be used to evaluate the independence of analysis for different values within a medium. The results of these studies will be compared to a set of corresponding experiments on visual search for conjunctions. These visual search tasks will conjoin the same values (e.g. color and orientation, color and motion) as those tested in the opposing induction and adaptation experiments. The prediction is that independence in the opposing adaptation experiments will correlate with slow, serial search in the conjunction task. The explanation lies in the heterogeneity of the distractor groups. In addition to psychophysical tasks with normal observers, the investigators propose to test patients with known losses (in particular, cortical color blindness) to verify the routing of information. Where supported by the data, the investigators shall extend these tests as a measure of relative function of different visual pathways that may be diagnostic of particular diseases.