Coding of Border Ownership in Monkey Visual Cortex Export

@article{citeulike:441282, abstract = {Areas V1 and V2 of the visual cortex have traditionally been conceived as stages of local feature representations. We investigated whether neural responses carry information about how local features belong to objects. Single-cell activity was recorded in areas V1, V2, and V4 of awake behaving monkeys. Displays were used in which the same local feature (contrast edge or line) could be presented as part of different figures. For example, the same light-dark edge could be the left side of a dark square or the right side of a light square. Each display was also presented with reversed contrast.We found significant modulation of responses as a function of the side of the figure in >50\% of neurons of V2 and V4 and in 18\% of neurons of the top layers of V1. Thus, besides the local contrast border information, neurons were found to encode the side to which the border belongs ("border ownership coding"). A majority of these neurons coded border ownership and the local polarity of luminance-chromaticity contrast. The others were insensitive to contrast polarity. Another 20\% of the neurons of V2 and V4, and 48\% of top layer V1, coded local contrast polarity, but not border ownership. The border ownership-related response differences emerged soon (<25 msec) after the response onset. In V2 and V4, the differences were found to be nearly independent of figure size up to the limit set by the size of our display (21{degrees}). Displays that differed only far outside the conventional receptive field could produce markedly different responses. When tested with more complex displays in which figure-ground cues were varied, some neurons produced invariant border ownership signals, others failed to signal border ownership for some of the displays, but neurons that reversed signals were rare.The influence of visual stimulation far from the receptive field center indicates mechanisms of global context integration. The short latencies and incomplete cue invariance suggest that the border-ownership effect is generated within the visual cortex rather than projected down from higher levels.}, author = {Zhou, Hong and Friedman, Howard S. and von der Heydt, Rudiger}, citeulike-article-id = {441282}, citeulike-linkout-0 = {http://www.jneurosci.org/cgi/content/abstract/20/17/6594}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/10964965}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=10964965}, day = {1}, journal = {J. Neurosci.}, keywords = {activity, area, awake, cortex, fields, figure-ground, macaque, monkey, nonclassical, organization, perception, perceptual, primate, receptive, segregation, single-unit, v1, v2, v4, visual}, month = {September}, number = {17}, pages = {6594--6611}, posted-at = {2009-03-21 23:21:41}, priority = {2}, title = {Coding of Border Ownership in Monkey Visual Cortex}, url = {http://www.jneurosci.org/cgi/content/abstract/20/17/6594}, volume = {20}, year = {2000} }

TY - JOUR ID - citeulike:441282 L3 - citeulike-article-id:441282 N2 - Areas V1 and V2 of the visual cortex have traditionally been conceived as stages of local feature representations. We investigated whether neural responses carry information about how local features belong to objects. Single-cell activity was recorded in areas V1, V2, and V4 of awake behaving monkeys. Displays were used in which the same local feature (contrast edge or line) could be presented as part of different figures. For example, the same light-dark edge could be the left side of a dark square or the right side of a light square. Each display was also presented with reversed contrast.We found significant modulation of responses as a function of the side of the figure in >50% of neurons of V2 and V4 and in 18% of neurons of the top layers of V1. Thus, besides the local contrast border information, neurons were found to encode the side to which the border belongs ("border ownership coding"). A majority of these neurons coded border ownership and the local polarity of luminance-chromaticity contrast. The others were insensitive to contrast polarity. Another 20% of the neurons of V2 and V4, and 48% of top layer V1, coded local contrast polarity, but not border ownership. The border ownership-related response differences emerged soon (<25 msec) after the response onset. In V2 and V4, the differences were found to be nearly independent of figure size up to the limit set by the size of our display (21{degrees}). Displays that differed only far outside the conventional receptive field could produce markedly different responses. When tested with more complex displays in which figure-ground cues were varied, some neurons produced invariant border ownership signals, others failed to signal border ownership for some of the displays, but neurons that reversed signals were rare.The influence of visual stimulation far from the receptive field center indicates mechanisms of global context integration. The short latencies and incomplete cue invariance suggest that the border-ownership effect is generated within the visual cortex rather than projected down from higher levels. IS - 17 JF - J. Neurosci. EP - 6611 TI - Coding of Border Ownership in Monkey Visual Cortex VL - 20 SP - 6594 KW - activity KW - area KW - awake KW - cortex KW - fields KW - figure-ground KW - macaque KW - monkey KW - nonclassical KW - organization KW - perception KW - perceptual KW - primate KW - receptive KW - segregation KW - single-unit KW - v1 KW - v2 KW - v4 KW - visual AU - Zhou, Hong AU - Friedman, Howard AU - von der Heydt, Rudiger PY - 2000/09/01/ UR - http://www.jneurosci.org/cgi/content/abstract/20/17/6594 ER -