Neuroimaging of shape similarity in object recognition

描述（由申请人提供）：拟议研究的目标是确定与视觉识别相关的神经基质。人脑中有一个区域被称为腹侧颞叶皮层（VTC），它与视觉识别有关，这是基于电生理和非人类灵长类动物病变研究的证据，以及临床观察表明，当大脑的这一区域受损时，视觉识别能力就会丧失。此外，人体病变研究和最近的功能神经影像学发现表明，VTC的不同区域可能对不同的物体类别有优先反应。对这些结果的一种流行解释是，专门的神经子系统致力于识别不同的对象类别。然而，认知行为研究表明，物体识别主要依赖于处理关于物体形状的信息，形状信息驱动类别组织。因此，本研究的论点是，事实上，VTC中特定类别的大脑激活模式可能反映了对物体识别至关重要的不同程度的形状信息处理。例如，像工具和家具这样的制造对象类别在形状上没有太多重叠，而面孔在形状上却有很大的重叠。大脑中似乎专门处理面部信息的区域可能与解决高度的形状相似性有关。功能磁共振成像（fMRI）在本建议中用于检查在目标识别过程中VTC的血流变化。第一个目标是确定VTC在处理与物体相关的形状信息中的作用。一种假设是后验VTC在将感知信息映射到存储的关于物体形状的信息中起关键作用。另一个假设考察了随着物体之间形状相似性参数化增加，VTC中fMRI反应的幅度和空间分布。当形状相似度较低时（如人造物体类别的情况下），后VTC区域可能参与其中，但前VTC区域可能被招募来解决高度形状相似的问题（如面部的情况）。第二个目标是将这种形状相似性框架与其他两种流行的类别特异性方法（分类学类别帐户和分类级别帐户）的功效进行比较。形状相似性可以解释VTC脑激活模式的分类类别差异和分类水平差异。分离视觉识别的适当认知处理组件，并将这些组件映射到功能神经解剖学中，对于理解脑损伤后视觉识别缺陷的本质，以及导致功能康复和恢复的潜在治疗是非常宝贵的。

DESCRIPTION (provided by applicant): The goal of the proposed research is to determine the neural substrates associated with visual recognition. An area of the human brain, referred to as ventral temporal cortex (VTC), is implicated in visual recognition based on evidence from electrophysiological and lesion studies with non-human primates and on clinical observations that visual recognition abilities are lost when this region of the brain is damaged. In addition, human lesion studies and recent functional neuroimaging findings suggest that different regions of VTC may preferentially respond to different object categories. A popular interpretation of these results is that specialized neural subsystems are dedicated to recognizing different object classes. Cognitive behavioral studies, however, have demonstrated that object recognition depends critically on processing information about an object's shape, and that shape information drives category organization. Consequently, the thesis of the present proposal is that category-specific patterns of brain activation in VTC may, in fact, reflect varying degrees of shape information processing that is crucial for object identification. For example, manufactured object categories like tools and furniture do not overlap much in shape, whereas faces overlap tremendously in shape. Brain areas that appear to be specific to face processing may, instead, be involved in resolving high degrees of shape similarity. Functional magnetic resonance imaging (fMRI) is used in the present proposal to examine blood-flow changes in VTC during object recognition. The first goal is to determine the role of VTC in processing shape information associated with objects. One hypothesis is that posterior VTC is critically involved in mapping perceptual information onto stored information about object form. Another hypothesis examines the magnitude and spatial distribution of fMRI response in VTC as shape similarity parametrically increases among objects. Posterior VTC regions are likely involved when shape similarity is low (as in the case of manufactured object categories), but anterior VTC regions are likely recruited to resolve high degrees of shape similarity (as in the case of faces). The second goal is to compare the efficacy of this shape similarity framework with two other popular approaches to category specificity - a taxonomic category account and a categorization-level account. Shape similarity may explain both taxonomic category differences and categorization level differences in brain activation patterns in VTC. Isolating the proper cognitive processing components of visual recognition and mapping these components to functional neuroanatomy is invaluable for understanding the nature of visual recognition deficits following brain damage, and for leading to potential therapies for rehabilitation and recovery of function.