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Showing papers on "Orientation column published in 1970"


Journal ArticleDOI
03 Oct 1970-Nature
TL;DR: Experiment has shown that two lines of different orientation interact with each other so that they seem to be displaced from one another in orientation, suggesting mutual inhibition between neighbouring columns in the visual cortex.
Abstract: Experiment has shown that two lines of different orientation interact with each other so that they seem to be displaced from one another in orientation. This could be explained in terms of mutual inhibition between neighbouring columns in the visual cortex.

589 citations


Journal ArticleDOI
TL;DR: Lesions injuring the white matter produced anterograde degeneration in the nucleus praetectalis, three pulvinar nuclei, the lateral geniculate nucleus and the pregeniculate nucleus, which must have resulted from the interruption of fibers originating in areas other than the lateral striate cortex, and passing beneath the site of the lesion.
Abstract: Laminar lesions made by the thermocoagulation in the lateral striate cortex of Saimiri reveal details of three distinct groups of descending fibers: interlaminar, cortico-cortical, and cortico-subcortical. The two most massive connections originate mainly from layer III. These are the interlaminar fibers terminating in the underlying layer V, and the systematically arranged projection upon area 18. Another cortical projection upon a narrow region in the superior temporal sulcus originates mainly from the infragranular layers, from which originate also the fibers passing to three subcortical structures, viz. the colliculus superior, the medial pulvinar and the griseum pontis. These subcortical projections are sparse compared to the interlaminar and cortico-cortical connections. In particular, no evidence was obtained that the lateral geniculate nucleus receives fibers from the lateral striate cortex. Lesions injuring the white matter, however, produced, in addition, anterograde degeneration in the nucleus praetectalis, three pulvinar nuclei, the lateral geniculate nucleus and the pregeniculate nucleus. This degeneration must have resulted from the interruption of fibers originating in areas other than the lateral striate cortex, and passing beneath the site of the lesion. The origin of the interlaminar fibers and of the association fibers upon area 18 provided strong evidence that, in Saimiri's striate cortex, the two sublayers traditionally referred to as sublayers IVa and IVb, actually form part of the conspicuously enlarged layer III which thus is subdivided into three distinct sublayers.

271 citations


Journal ArticleDOI
TL;DR: A neurophysiological theory for binocular single vision and depth discrimination is put forward as a theoretical framework for the construction of the horopter for the cat as well as a region analogous to Panum's fusional area in man.
Abstract: Of binocularly-activated striate neurons only a proportion have their two receptive fields in exactly corresponding positions in the contralateral hemifield Those which are not corresponding are said to show receptive field disparity Because the eyes diverge in the anaesthetized and paralyzed preparation, the binocular receptive fields are horizontally separate With increasing retinal eccentricity there is a gradual decrease in this horizontal separation as well as progressive changes in the local receptive field disparities With increasing horizontal retinal eccentricity there is a progressive increase in horizontal receptive field disparities together with a smaller decrease in vertical disparities Receptive field disparities are relatively unaffected by increasing vertical retinal eccentricity

186 citations


Journal ArticleDOI
TL;DR: The authors showed that the pattern of degeneration in layer IV of the striate cortex was indeed arranged in parallel stripes that alternated with zones of sparing, and postulated that the (striate) cortex can therefore be thought of as subdivided into slab-shaped columns with walls perpendicBrain Research, 23 (1970) 185-191.

135 citations


Journal ArticleDOI
Irving T. Diamond1, M. Snyder1, H.P. Killackey1, Jane Ja1, William C. Hall1 
TL;DR: It is suggested that V II may be the result of convergent evolution in different mammalian lines of descent, and the evidence from Striate area lesions suggests that the lateral geniculate projections are confined to the striate area as defined by cytoarchitecture, which in turn corresponds precisely with visual area I asdefined by electrophysiological recording.
Abstract: Cortical lesions were placed in 18 hemispheres, and thalamic degeneration was studied after a survival period of at least six weeks. Very small lesions within the striate area produced complete degeneration of neurons in a column through the lateral geniculate, from medial to lateral borders and comprising all of the laminae. Lesions of various loci within the striate area reveal a precise topographic projection, with the rostral lateral geniculate sending fibers to the caudal extremity of the striate area and the caudal lateral geniculate projecting to the rostral extremity of the striate; further, the dorso-ventral dimension in the lateral geniculate projects to the medio-lateral dimension in the striate area. Finally, the evidence from striate area lesions suggests that the lateral geniculate projections are confined to the striate area as defined by cytoarchitecture, which in turn corresponds precisely with visual area I as defined by electrophysiological recording. This conclusion is supported by the failure to find retrograde degeneration after lesions of the belt of cortex adjacent to the striate area. The temporal area which occupies an extensive section from V II to the rhinal fissure and the auditory cortex and which has been shown to be a visual receiving area, is the target of essential projections from the pulvinar. The pulvinar also sends sustaining collaterals within the temporal area and probably outside as well, especially to V II. However, the very crude topographic organization apparent in the pulvinar projections does not seem to be sufficiently refined to account for the organization of V II. A suggestion was made in closing that V II may be the result of convergent evolution in different mammalian lines of descent.

84 citations


Journal ArticleDOI
TL;DR: Binocularly driven single units were recorded in the cat's striate cortex and the two monocular receptive fields were stimulated simultaneously to assess the optimal positioning of the image in both eyes to give the best binocular response.
Abstract: 1. Binocularly driven single units were recorded in the cat's striate cortex. For each neurone the two monocular receptive fields were stimulated simultaneously in order to assess the optimal positioning of the image in both eyes to give the best binocular response. 2. The electrode was driven perpendicular to the surface of the brain to explore cortical columns, all the cells of which are known to have the same preferred target orientation. 3. All orientation columns were found to fit into one of two classes according to their binocular organization. 4. In a constant depth column the receptive fields of binocular neurones cover a small retinal area and they are laid out in almost identical arrays in the two eyes. Consequently, the horizontal disparity is practically the same for all the units. The depth column as a whole is viewing a thin sheet of visual space, a few degrees wide, floating at some distance from the cat. There may be about 0·6° disparity difference between neighbouring depth columns. 5. In a constant direction column the binocular units' fields are all super-imposed on the retina contralateral to the hemisphere containing the column. In the ipsilateral eye they are more scattered horizontally. Therefore the horizontal disparity varies enormously from cell to cell and the column as a whole is viewing a cylinder of visual space directed towards the contralateral eye. Neighbouring direction columns may vary by about 4° in their oculocentric visual direction. 6. This columnar arrangement is probably important for space perception in the cat. Activity in only one depth and one direction column would specify the orientation and the three-dimensional locus of an object in space. 7. The two types of column may be involved in the control of disjunctive and conjugate eye movements.

79 citations


Journal ArticleDOI
31 Jan 1970-Nature
TL;DR: The projection from the contralateral eye dominates the cat's visual cortex, and stereoscopic vision may depend on this difference in the two projections.
Abstract: The projection from the contralateral eye dominates the cat's visual cortex. Binocular neurones in any small region have their receptive fields more widely scattered over the ipsilateral retina than over the contralateral. Stereoscopic vision may depend on this difference in the two projections.

76 citations


Journal ArticleDOI
24 Apr 1970-Science
TL;DR: By chromatic adaptation, all three cone mechanisms of rhesus monkey vision can be identified in single neurons of striate cortex and indicates that striate cortical cells tend to be more wavelength discriminating than cells at lower stages of the primate visual system.
Abstract: By chromatic adaptation, all three cone mechanisms of rhesus monkey vision can be identified in single neurons of striate cortex. This trichromatic inter-action occurs in cells sensitive to color and indicates that striate cortical cells tend to be more wavelength discriminating than cells at lower stages of the primate visual system.

49 citations


Journal ArticleDOI
31 Jan 1970-Nature
TL;DR: A post-stimulus histogram (PSH) is obtained, which displays the number of neuronal discharges occurring at various times after each of a series of identical retinal stimuli, and indicates the distribution of probability of unit discharge, following visual excitation.
Abstract: THE primary visual receiving area of the mammalian cerebral cortex is readily excited by sudden alterations in the intensity of light falling on either retina. Techniques developed by Hubel and Wiesel4 have made it possible to record the responses of individual cortical neurones to appropriately placed retinal stimuli of the right shape. The response of single units to the proper form of physiological stimulus is sometimes so clear that a single flash or movement of a pattern of light in the visual field will invariably produce a burst of discharges from the recorded neurone. Most neurones in the lightly anaesthetized or unanaesthetized visual cortex, however, are less predictable in their behaviour, and their response to retinal excitation is best demonstrated by averaging procedures2. A post-stimulus histogram (PSH) is obtained, which displays the number of neuronal discharges occurring at various times after each of a series of identical retinal stimuli. Thus the PSH indicates the distribution of probability of unit discharge, following visual excitation.

9 citations


Journal ArticleDOI
TL;DR: By systematically varying the spatial location of these two blanked points relative to the three unblanked points, a start is made towards mapping the shape of visual inhibitory fields in man.
Abstract: Five point sources of light were displayed sequentially in a horizontal line, with .45 in. of separation between each point, employing a computer-based cathode-ray tube display system. If a particular display order and appropriate display rate is employed, then the first two points being displayed will not be perceived. By systematically varying the spatial location of these two blanked points relative to the three unblanked points, a start is made towards mapping the shape of visual inhibitory fields in man, and this general technique is related to the work of Hartline and of Ratliff on lateral inhibition and to that of Hubel and Wiesel with receptive fields in the cat and monkey striate cortex.

4 citations


Journal ArticleDOI
TL;DR: Receptive fields of neurons in Area 17 of the visual cortex were investigated in cats and an effect of adaptive inhibition was found in which constant illumination of an area in the center of the receptive field inhibits the response in another part.
Abstract: Receptive fields of neurons in Area 17 of the visual cortex were investigated in cats. Concentrically shaped fields, fields responding selectively to orientation of a strip or edge, and fields which can be regarded as intermediate between the first two types are described. The boundary between zones of summation and of lateral inhibition coincides in some receptive fields with the boundary between central and peripheral zones with opposite forms of response, while in other fields they do not coincide. For some cells there is no peripheral zone or it may disappear with worsening of the state of function. Cells were observed for which an increase in area of the stimulus in the central zone inhibits the response reaction. Analysis of these data suggests that several cells of the geniculate ganglion converge on some cortical neurons, and several cortical cells on others. An effect of adaptive inhibition was found in which constant illumination of an area in the center of the receptive field inhibits the response in another part. It is shown that this effect is unconnected with the action of scattered light. Constant illumination of the peripheral part of the receptive field deinhibits adaptive inhibition. The boundary between the zones of summation and of lateral inhibition coincides with the boundary between the zones of adaptive inhibition and deinhibition.