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The superior colliculus (SC) has been implicated in spatial analyses of the environment, although few behavioral studies have explicitly tested this role. To test its imputed role in spatial analyses, we used a battery of four spatial tasks combined with unilateral and bilateral cooling deactivation of the upper and intermediate layers of the superior(More)
This review compares the behavioral, physiological and anatomical repercussions of lesions of primary visual cortex incurred by developing and mature humans, monkey and cats. Comparison of the data on the repercussions following lesions incurred earlier or later in life suggests that earlier, but not later, damage unmasks a latent flexibility of the brain(More)
Extrastriate visual cortex of the ventral-posterior suprasylvian gyrus (vPS cortex) of freely behaving cats was reversibly deactivated with cooling to determine its role in performance on a battery of simple or masked two-dimensional pattern discriminations, and three-dimensional object discriminations. Deactivation of vPS cortex by cooling profoundly(More)
The long-term morphological consequences on laminar thickness and neuron survival were assessed in cerebral cortical area PMLS following excision of visual cortical areas 17, 18, and 19 from adult and adolescent cats and from neonatal kittens. Following excisions from kittens, layers III, V, and VI in area PMLS were reduced in thickness and there was a(More)
We used reversible cooling deactivation to compare the functions of cortices lining the middle suprasylvian (MS) sulcus and forming the ventral portion of the posterior suprasylvian (vPS) gyrus. A battery of attentional, motion and mnemonic processing tasks were used and performance was examined during deactivation of each region. The results show a clear(More)
Bilateral removal of the cortical visual area in newborn cats produces degeneration of retinal ganglion cells. Measurements of over 4,000 cells and calculation of neuron densities from sample areas of retina in the adult show that the medium sized cell population in peripheral retina is reduced by 68%, whereas the populations of small and large cells are(More)
Transneuronal retrograde degeneration of retinal ganglion cells was investigated following neonatal visual cortex ablation in the cat. After a survival time of at least 18 months, retinal ganglion cells projecting to the thalamus were labelled by retrograde transport of horseradish peroxidase. Filled ganglion cells were classified into alpha, beta and gamma(More)
Sparing of visual function was studied in cats with bilateral cortical damage to Areas 17 and 18 and most of Area 19. Cats with lesions made in 2 stages, on Postnatal (P) Days 3 and 6, in 1 stage on P6, or in 1 stage in adulthood were compared with sham-operated controls on 10 visual discrimination tasks. On some tasks, both groups of cats that underwent(More)
Performance by cats with lesions of the visual cortex made in infancy or adulthood was examined on tasks of visually guided behavior that do not require specific training. Cats with lesions confined to areas 17, 18, and 19 made during the 1st postnatal week showed more sparing of function on a visual cliff, at orienting to targets suddenly appearing in the(More)