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Orientation column

About: Orientation column is a research topic. Over the lifetime, 1142 publications have been published within this topic receiving 130169 citations.


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Journal ArticleDOI
TL;DR: It is concluded that in dark-reared cats, but not normal ones, the orientation and direction sensitivities of cells in the LGNd and visual cortex do not differ quantitatively or qualitatively, and during normal development intracortical mechanisms appear to expand upon and/or modify the weak orientation and Direction sensitivity of their inputs.
Abstract: Visual deprivation in early life profoundly affects the characteristic sensitivity of visual cortical cells to stimulus orientation and direction. Recently, relay cells in the lateral geniculate nucleus (LGNd) have been shown to exhibit significant degrees of orientation and direction sensitivity. The effects of visual deprivation upon these properties of subcortical cells are unknown. In this study cats were reared from birth to 6–12 months of age in total darkness; the orientation and direction sensitivities of area 17 (striate cortex) and LGNd cells were compared. All cells were studied using identical quantitative techniques and statistical tests designed to analyze distributions of angles. The results confirm previous work and indicate that the orientation and direction sensitivities of cells in area 17 are profoundly reduced by dark rearing. In marked contrast, these properties of LGNd relay cells are unaffected. The result is that, unlike in the normal cat, in dark-reared cats the orientation and direction sensitivities of cells in the LGNd and visual cortex do not differ. It is concluded that (1) the orientation and direction sensitivities of cortical cells contribute little, if at all, to the sensitivities of LGNd cells since LGNd cells exhibit normal sensitivities even though the cortical cells projecting to them exhibit greatly reduced sensitivities and (2) during normal development intracortical mechanisms appear to expand upon and/or modify the weak orientation and direction sensitivities of their inputs. These intracortical mechanisms depend upon normal visual experience since in dark-reared cats, but not normal ones, the orientation and direction sensitivities of cells in the LGNd and visual cortex do not differ quantitatively or qualitatively.

44 citations

Journal ArticleDOI
TL;DR: The results confirm previous electrophysiological studies on the location, size and organization of rat primary visual cortex and serves as a precursor before examining animal models of retinal degeneration and the effectiveness of potential therapies to stem retinal disease.

44 citations

Journal ArticleDOI
TL;DR: The present data indicate that neurons in this association area respond to restricted visual stimuli in a specific manner, and this sensory-specific visual input is dependent upon participation of visual cortex.

44 citations

Journal ArticleDOI
TL;DR: Analysis of the development and structure of orientation (OR) and ocular dominance maps in the primary visual cortex of cats and monkeys using the elastic net algorithm suggests that developmental order can be predicted from the final OR and OD periodicities.
Abstract: The development and structure of orientation (OR) and ocular dominance (OD) maps in the primary visual cortex of cats and monkeys can be modelled using the elastic net algorithm, which attempts to find an 'optimal' cortical representation of the input features. Here we analyse this behaviour in terms of parameters of the feature space. We derive expressions for the OR periodicity, and the first bifurcation point as a function of the annealing parameter using the methods of Durbin et al (Durbin R, Szeliski R and Yuille A 1989 Neural Computation 1 348-58). We also investigate the effect of the relative order of OR and OD development on overall map structure. This analysis suggests that developmental order can be predicted from the final OR and OD periodicities. In conjunction with experimentally measured values for these periodicities, the model predicts that (i) in normal macaques OD develops first, (ii) in normal cats OR develops first and (iii) in strabismic cats OD develops first.

44 citations

Journal ArticleDOI
TL;DR: The mammalian visual cortex contains a complex mosaic of areas that are richly connected with one another, and both macroscopic and microscopic aspects of cortical organization, and of information flow within and between functionally specialized processing streams are advanced.

43 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231
20223
20212
20208
20192
20189