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Spatial Reference Frames for Object Recognition: Tuning for Rotations in Depth

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dc.contributor.author Logothetis, N.K. en_US
dc.contributor.author Pauls, J. en_US
dc.contributor.author Poggio, T. en_US
dc.date.accessioned 2004-10-08T20:36:01Z
dc.date.available 2004-10-08T20:36:01Z
dc.date.issued 1995-03-01 en_US
dc.identifier.other AIM-1533 en_US
dc.identifier.uri http://hdl.handle.net/1721.1/6637
dc.description.abstract The inferior temporal cortex (IT) of monkeys is thought to play an essential role in visual object recognition. Inferotemporal neurons are known to respond to complex visual stimuli, including patterns like faces, hands, or other body parts. What is the role of such neurons in object recognition? The present study examines this question in combined psychophysical and electrophysiological experiments, in which monkeys learned to classify and recognize novel visual 3D objects. A population of neurons in IT were found to respond selectively to such objects that the monkeys had recently learned to recognize. A large majority of these cells discharged maximally for one view of the object, while their response fell off gradually as the object was rotated away from the neuron"s preferred view. Most neurons exhibited orientation-dependent responses also during view-plane rotations. Some neurons were found tuned around two views of the same object, while a very small number of cells responded in a view- invariant manner. For five different objects that were extensively used during the training of the animals, and for which behavioral performance became view-independent, multiple cells were found that were tuned around different views of the same object. No selective responses were ever encountered for views that the animal systematically failed to recognize. The results of our experiments suggest that neurons in this area can develop a complex receptive field organization as a consequence of extensive training in the discrimination and recognition of objects. Simple geometric features did not appear to account for the neurons" selective responses. These findings support the idea that a population of neurons -- each tuned to a different object aspect, and each showing a certain degree of invariance to image transformations -- may, as an assembly, encode complex 3D objects. In such a system, several neurons may be active for any given vantage point, with a single unit acting like a blurred template for a limited neighborhood of a single view. en_US
dc.format.extent 1535116 bytes
dc.format.extent 1799567 bytes
dc.format.mimetype application/postscript
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.relation.ispartofseries AIM-1533 en_US
dc.title Spatial Reference Frames for Object Recognition: Tuning for Rotations in Depth en_US


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