Object category structure in response patterns of neuronal population in monkey inferior temporal cortex. Export

@article{Kiani2007, abstract = {Our mental representation of object categories is hierarchically organized, and our rapid and seemingly effortless categorization ability is crucial for our daily behavior. Here, we examine responses of a large number (>600) of neurons in monkey inferior temporal (IT) cortex with a large number (>1,000) of natural and artificial object images. During the recordings, the monkeys performed a passive fixation task. We found that the categorical structure of objects is represented by the pattern of activity distributed over the cell population. Animate and inanimate objects created distinguishable clusters in the population code. The global category of animate objects was divided into bodies, hands, and faces. Faces were divided into primate and nonprimate faces, and the primate-face group was divided into human and monkey faces. Bodies of human, birds, and four-limb animals clustered together, whereas lower animals such as fish, reptile, and insects made another cluster. Thus the cluster analysis showed that IT population responses reconstruct a large part of our intuitive category structure, including the global division into animate and inanimate objects, and further hierarchical subdivisions of animate objects. The representation of categories was distributed in several respects, e.g., the similarity of response patterns to stimuli within a category was maintained by both the cells that maximally responded to the category and the cells that responded weakly to the category. These results advance our understanding of the nature of the IT neural code, suggesting an inherently categorical representation that comprises a range of categories including the amply investigated face category.}, author = {Kiani, Roozbeh and Esteky, Hossein and Mirpour, Koorosh and Tanaka, Keiji}, citeulike-article-id = {3504849}, citeulike-linkout-0 = {http://dx.doi.org/10.1152/jn.00024.2007}, doi = {10.1152/jn.00024.2007}, institution = {Research Group for Brain and Cognitive Sciences, School of Medicine, Shaheed Beheshti University, P.O. Box 19835-181, Tehran, Iran.}, journal = {J Neurophysiol}, keywords = {action, analysis, animal, animals, behavior, brain, classificationphysiology, cluster, cytology, file-import-08-11-12, humans, lobe, macaca, mapping, methods, mulatta, neurons, pathways, pattern, photic, physiology, potentials, probability, reaction, recognition, stimulation, temporal, time, visual}, month = {Jun}, number = {6}, pages = {4296--4309}, posted-at = {2008-11-12 02:55:13}, priority = {2}, title = {Object category structure in response patterns of neuronal population in monkey inferior temporal cortex.}, url = {http://dx.doi.org/10.1152/jn.00024.2007}, volume = {97}, year = {2007} }

TY - JOUR ID - Kiani2007 L3 - citeulike-article-id:3504849 N2 - Our mental representation of object categories is hierarchically organized, and our rapid and seemingly effortless categorization ability is crucial for our daily behavior. Here, we examine responses of a large number (>600) of neurons in monkey inferior temporal (IT) cortex with a large number (>1,000) of natural and artificial object images. During the recordings, the monkeys performed a passive fixation task. We found that the categorical structure of objects is represented by the pattern of activity distributed over the cell population. Animate and inanimate objects created distinguishable clusters in the population code. The global category of animate objects was divided into bodies, hands, and faces. Faces were divided into primate and nonprimate faces, and the primate-face group was divided into human and monkey faces. Bodies of human, birds, and four-limb animals clustered together, whereas lower animals such as fish, reptile, and insects made another cluster. Thus the cluster analysis showed that IT population responses reconstruct a large part of our intuitive category structure, including the global division into animate and inanimate objects, and further hierarchical subdivisions of animate objects. The representation of categories was distributed in several respects, e.g., the similarity of response patterns to stimuli within a category was maintained by both the cells that maximally responded to the category and the cells that responded weakly to the category. These results advance our understanding of the nature of the IT neural code, suggesting an inherently categorical representation that comprises a range of categories including the amply investigated face category. IS - 6 JF - J Neurophysiol EP - 4309 TI - Object category structure in response patterns of neuronal population in monkey inferior temporal cortex. VL - 97 SP - 4296 KW - action KW - analysis KW - animal KW - animals KW - behavior KW - brain KW - classificationphysiology KW - cluster KW - cytology KW - file-import-08-11-12 KW - humans KW - lobe KW - macaca KW - mapping KW - methods KW - mulatta KW - neurons KW - pathways KW - pattern KW - photic KW - physiology KW - potentials KW - probability KW - reaction KW - recognition KW - stimulation KW - temporal KW - time KW - visual AU - Kiani, Roozbeh AU - Esteky, Hossein AU - Mirpour, Koorosh AU - Tanaka, Keiji PY - 2007/Jun// UR - http://dx.doi.org/10.1152/jn.00024.2007 ER -