Neural and Behavioral Analyses of the Representation of Shape

形状表征的神经和行为分析

• 批准号: 0617699
• 负责人: Irving Biederman
• 金额: $ 54.59万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0617699&HistoricalAwards=false
• 关键词: Neural; Behavioral; Analyses; Representation; Shape

In a fraction of a second a human observer can easily comprehend an image of an object or scene that has never been encountered before. Knowledge of the neural basis of this remarkable ability has been advanced by the discovery of a cortical area that is activated by the shape of intact objects but not by scrambled versions of these same images. This brain region, termed the lateral occipital complex (LOC), is activated in functional magnetic resonance imaging (fMRI) studies by both familiar and unfamiliar objects. The LOC is also activated by both photographs and line drawings of the same object, indicating that the surface qualities are represented elsewhere. And, bilateral lesions to LOC have been shown to produce a complete inability to recognize objects on the basis of their shape. LOC thus represents physical shape to which, presumably, semantic information, including a name, can be associated. With support from the National Science Foundation, Dr. Irving Biederman and colleagues at the University of Southern California will conduct a series of experiments that aim to better determine how shape is represented in the LOC. One project will test whether parts and relations have distinguishable neural loci. Other projects will assess whether the coding of shape in the LOC is accomplished in terms of local image features, parts, global shape or concepts, and the locus and extent to which invariant coding of shape - which allows an object to be recognized as unchanged even when it is viewed at a different position in the visual field, at a different size, at a different orientation, or lit from a different direction - is manifested in LOC. This research will fill a critical gap between human psychophysical research on object recognition and work on single-neuron recordings in response shape variations that have been performed in non-human primates. Although the homologues between human and non-human primate primary sensory and motor cortices are well established there are significant questions concerning the homologues of later, perceptual association areas. Perhaps the most important potential impact of the proposed research is that it could allow us to understand the neural representations that subserve not only object recognition but cognition more generally.

在几分之一秒的时间里，人类观察者可以很容易地理解以前从未遇到过的物体或场景的图像。 由于发现了一个皮层区域，这个区域会被完整物体的形状激活，但不会被这些相同图像的混乱版本激活，因此对这种非凡能力的神经基础的认识得到了进一步的发展。该大脑区域被称为枕外侧复合体（LOC），在功能磁共振成像（fMRI）研究中，熟悉和不熟悉的物体都会激活该区域。同一物体的照片和线条画也会激活这种感觉，这表明表面质量在其他地方得到了体现。 而且，双侧病变到小脑已经被证明产生完全不能根据物体的形状识别物体。因此，它表示物理形状，可能与语义信息（包括名称）相关联。 在美国国家科学基金会的支持下，南加州大学的欧文·比德曼博士和他的同事们将进行一系列实验，旨在更好地确定形状在大脑中是如何表现的。一个项目将测试部分和关系是否有可区分的神经位点。其他项目将评估在局部图像特征、部分、整体形状或概念方面是否完成了对物体形状的编码，以及形状不变编码的轨迹和程度--这使得即使在视野中的不同位置、不同大小、不同方向观察物体时，也能将物体识别为未改变，或从不同的方向被照亮--都表现为反射。 这项研究将填补人类心理物理学对物体识别的研究与在非人类灵长类动物中进行的单神经元响应形状变化记录之间的关键空白。 虽然人类和非人类灵长类动物的初级感觉和运动皮层之间的同源物已经很好地建立，但关于后来的知觉关联区域的同源物存在重大问题。 也许这项研究最重要的潜在影响是，它可以让我们了解不仅有助于物体识别，而且有助于更普遍的认知的神经表征。