Patterns of activity in the categorical representations of objects
Patterns of activity in the categorical representations of objects
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DOI：
10.1162/089892903322307429
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发表时间：
2003-07-01
影响因子：
3.2
通讯作者：
He, S
中科院分区：
文献类型：
--
作者：
Carlson, TA;Schrater, P;He, S
近年来，物体知觉已成为功能磁共振成像研究的一个主题。然而，人类大脑中物体的皮质表征的本质仍然存在争议。功能磁共振成像数据的分析传统上集中在激活与呈现各种刺激相关的个体素。目前的分析方法功能成像数据作为集体信息的刺激。将大脑中的活动与刺激联系起来被视为模式分类问题。线性判别分析用于重新分析Ishai等人（2000）最初发表的一组数据，可从fMRIDC获得（登录号2-2000- 1113 D）。新分析的结果表明，将一类物体与其他类别区分开来的活动模式在很大程度上是相互独立的，无论是在活动方面还是在空间重叠方面。用于从相位加扰控制刺激中检测对象的信息在区分一个对象类别与另一个对象类别中不是必不可少的。此外，在扫描过程中执行对象匹配任务显着提高了从控制中预测对象的能力，但对对象分类的影响很小，这表明基于任务的注意力益处对对象类别是非特异性的。
Object perception has been a subject of extensive fMRI studies in recent years. Yet the nature of the cortical representation of objects in the human brain remains controversial. Analyses of fMRI data have traditionally focused on the activation Of individual voxels associated with presentation of various stimuli. The current analysis approaches functional imaging data as collective information about the stimulus. Linking activity in the brain to a stimulus is treated as, a pattern-classification problem. Linear discriminant analysis as was used to reanalyze a set of data originally published by Ishai et al. (2000), available From the fMRIDC (accession no. 2-2000-1113D). Results of the new analysis reveal that patterns of activity that distinguish one category of objects from other categories are largely independent of one another, both in terms of the activity and spatial overlap. The information used to detect objects from phase-scrambled control stimuli is not essential in distinguishing one object category from another. Furthermore, performing an object-matching task during the scan significantly improved the ability to predict objects from controls, hut had minimal effect on object classification, suggesting that the task-based attentional benefit was nonspecific to object categories.