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Visual Adaptation, Selective Attention, and Shape Coding

视觉适应、选择性注意和形状编码

基本信息

批准号：
6946785
负责人：
SATORU SUZUKI
金额：
$ 22.28万
依托单位：
NORTHWESTERN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-08-01 至 2007-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6946785
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

项目摘要

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.

经典的视觉后效提供了一个强大的工具，psychopperically特征的感受野特性的神经元参与编码的本地图像功能，提供了一个生理指定的感受野V 1和感知的细胞之间的联系。然而，后效的应用主要限于研究局部特征的低级编码，因为后效带有早期处理的特征（例如，retinotopy，用于定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（在简短的适应测试间隔之后，用简短的测试模式探测简短的适应），可以对全局形状属性（如纵横比，倾斜度，锥度，曲率和凸度）产生后效。这些简短的形状后效带有高级编码的签名（例如，位置、比例和/或限定表面特征的公差）。因此，简短的形状后效是有前途的工具，用于表征的处理阶段，在该阶段中，全球配置的定向轮廓系统编码。这种“中级”视觉编码的详细表征将扩展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的表示的编码的理解。该提案的目标有三个方面。在目标1中，将仔细指定用于产生全局形状后效（与局部图像后效相对）的时间要求，以细化简短的形状后效，作为探测全局形状编码的工具。在目标2中，简短的形状后效将被用来表征感受野特性和性质的心理特征在全局形状属性编码阶段进行总体编码。在现实世界的环境中，对象经常重叠，全局形状属性的位置容忍编码不能被认为没有参考的注意力选择机制。与这个想法相一致的是，短暂的形状后效被证明对注意力很敏感。因此，在目标3中，实验被设计成调查观察者的注意和图像参数交互以选择用于全局形状编码的单个形状。因此，拟议的三重调查将提供一个彻底的心理物理表征的感受野和编码性能的中到高层次的形状表示，其激活取决于物理性质的刺激和注意。结果将开始提供更高皮层视觉区域中生理指定的感受野之间的联系（例如，在腹侧的“图案处理流”，如V4和IT）和整体形状属性的感知。