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底物。人类大脑的一个区域被称为腹侧颞叶皮质(VTC)，它与视觉识别有关，这是基于来自对非人类灵长类动物的电生理和损伤研究的证据，以及临床观察，即当大脑的这一区域受损时，视觉识别能力会丧失。此外，人类损伤研究和最近的功能神经成像发现表明，VTC的不同区域可能优先对不同的对象类别做出反应。对这些结果的一种流行解释是，专门的神经系统致力于识别不同的对象类别。然而，认知行为研究表明，物体识别在很大程度上依赖于对物体形状信息的处理，而形状信息驱动着类别组织。因此，本建议的论点是，职业训练局特定类别的大脑激活模式实际上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，工具和家具等制造的对象类别在形状上重叠不多，而面在形状上重叠很大。相反，看起来特定于面部处理的大脑区域可能参与了解决高度形状相似性的问题。功能磁共振成像(FMRI)在本方案中用于检测VTC在物体识别过程中的血流变化。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VTC关键地参与了将知觉信息映射到关于物体形状的存储信息上。另一种假设考察了VTC中fMRI反应的大小和空间分布，因为对象之间的形状相似性参数增加。当形状相似性较低时，可能涉及后VTC区域(如在制造对象类别的情况下)，但前VTC区域可能被招募来解决高程度的形状相似(如在面部的情况)。第二个目标是将该形状相似性框架与另外两种流行的类别专用性方法--分类类别帐户和分类级别帐户--进行比较。形状相似性可以解释VTC脑激活模式的分类分类差异和分类水平差异。分离视觉识别的适当认知加工成分并将这些成分映射到功能神经解剖学上，对于了解脑损伤后视觉识别缺陷的性质以及为康复和功能恢复提供潜在的治疗方法是非常有价值的。

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.