Population dynamics of face-responsive neurons in the inferior temporal cortex
Population dynamics of face-responsive neurons in the inferior temporal cortex
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DOI：
10.1093/cercor/bhh209
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发表时间：
2005-08-01
期刊：
影响因子：
3.7
通讯作者：
Kawano, K
中科院分区：
文献类型：
--
作者：
Matsumoto, N;Okada, M;Kawano, K
猴子下颞叶(IT)皮层的神经元对复杂的视觉刺激(如面部)有选择性地做出反应。IT皮层中的单个神经元在其时间放电模式中编码关于视觉刺激的不同类型的信息。为了理解在IT皮层中群体水平编码的信息的时间方面，我们将主成分分析(PCA)应用于一组神经元的反应。记录每个神经元的反应，同时呈现由人和猴子的几何形状和面部组成的视觉刺激。我们发现，总体分类，即人脸、猴脸和形状，发生在群体反应的早期，而精细分类发生在群体反应的后期，在全局类别的每个成员中。一种混合了高斯分析的聚类分析证实，答复较早部分的集群代表了全球类别。此外，前一部分的簇被分成对应于反应后半部分的人类身份或猴子表情的子簇，即使在子簇出现后，全局分类仍保持不变。结果表明，测试刺激的等级关系在时间上由IT神经元的群体反应来表示。
Neurons in the inferior temporal (IT) cortex of monkeys respond selectively to complex visual stimuli, such as faces. Single neurons in the IT cortex encode different kinds of information about visual stimuli in their temporal firing patterns. To understand the temporal aspects of the information encoded at a population level in the IT cortex, we applied principal component analysis (PCA) to the responses of a population of neurons. The responses of each neuron were recorded while visual stimuli that consisted of geometric shapes and faces of humans and monkeys were presented. We found that global categorization, i.e. human faces versus monkey faces versus shapes, occurred in the earlier part of the population response, and that fine categorization occurred within each member of the global category in the later part of the population response. A cluster analysis, a mixture of Gaussians analysis, confirmed that the clusters in the earlier part of the responses represented the global category. Moreover, the clusters in the earlier part separated into sub-clusters corresponding to either human identity or monkey expression in the later part of the responses, and the global categorization was maintained even after the appearance of the sub-clusters. The results suggest that a hierarchical relationship of the test stimuli is represented temporally by the population response of IT neurons.