Visual Adaptation, Selective Attention, and Shape Coding

视觉适应、选择性注意和形状编码

• 批准号: 6681200
• 负责人: SATORU SUZUKI
• 金额: $ 22.28万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6681200
• 关键词: attention; behavior test; behavioral /social science research tag; clinical research; human subject; neural information processing; psychophysics; stimulus /response; visual feedback; visual perception; visual stimulus

Classic visual aftereffects have provided a powerful tool for psychophysically characterizing the receptive field properties of neural units involved in coding local image features, providing a link between physiologically specified receptive fields of cells in V 1 and perception. However, the application of aftereffects has been limited primarily to studying low-level coding of local features because the aftereffects bore signatures of early processing (e.g., retinotopy, narrow tunings for orientation and spatial frequency). Recently, Suzuki and colleagues and others have reported that under specific temporal conditions (brief adaptation probed with a brief test pattern following a brief adapt-to-test interval), aftereffects can be induced for global shape attributes such as aspect ratio, skew, taper, curvature, and convexity. These brief shape aftereffects bear signatures of high-level coding (e.g., tolerance for position, scale, and/or defining surface features). Brief shape aftereffects are thus promising as a tool for characterizing a processing stage in which global configurations of oriented contours are systematically coded. Detailed characterization of this "mid-level" visual coding will expand understanding of how visual pattern processing evolves from the coding of local image features to the coding of various intermediate geometric features, and eventually to the coding of representations of meaningful objects. The oal of this proposal is three-fold. In Aim 1, the temporal requirements for producing global shape aftereffects (as opposed to local image aftereffects) will be carefully specified to refine brief shape aftereffects as a tool for probing global shape coding. In Aim 2, brief shape aftereffects will be used to psychophysically characterize the receptive field properties and the nature of population coding operating at the stage of coding global shape attributes. In a real-world environment where objects routinely overlap, position-tolerant coding of global shape attributes cannot be considered without reference to an attentional selection mechanism. Consistent with this idea, brief shape aftereffects have been shown to be sensitive to attention. Thus, in Aim 3, the experiments are designed to investigate how observers' attention and image parameters interact to select individual shapes for global shape coding. Thus, the proposed three-fold investigation will provide a thorough psychophysical characterization of the receptive field and coding properties of the mid- to high-level shape representation whose activation depends on both the physical properties of the stimuli and attention. The results will begin to provide a link between the physiologically specified receptive fields in the higher cortical visual areas (e.g., in the ventral "pattern processing stream" such as V4 and IT) and perception of global shape attributes.

经典的视觉后遗症提供了一个强大的心理物理工具来表征参与编码局部图像特征的神经单元的感受野特性，提供了生理上指定的v1细胞的感受野与感知之间的联系。然而，后效的应用主要局限于研究局部特征的低水平编码，因为后效具有早期处理的特征（例如，视网膜切除，方向和空间频率的窄调谐）。最近，Suzuki及其同事和其他人报告说，在特定的时间条件下（在短暂的适应-测试间隔之后用短暂的测试模式探索短暂的适应），可以诱导整体形状属性（如长宽比、倾斜、锥度、曲率和凸度）的后效应。这些简短的形状后遗症具有高级编码的特征（例如，对位置、尺度和/或定义表面特征的公差）。因此，简短的形状后效很有希望作为表征一个处理阶段的工具，在这个阶段中，定向轮廓的全局配置被系统地编码。对这种“中级”视觉编码的详细描述将扩大对视觉模式处理如何从局部图像特征的编码发展到各种中间几何特征的编码，并最终发展到有意义对象表示的编码的理解。这一提议的目标有三个方面。在目标1中，将仔细指定产生全局形状后效（与局部图像后效相反）的时间要求，以完善简短的形状后效，作为探测全局形状编码的工具。在目标2中，简短的形状后效将用于心理物理表征接受野的性质和性质