Subtotal lesions of the visual cortex impair discrimination of hidden figures by cats.

Abstract

Cats with partial or nearly total ablation of areas 17, 18, and 19 were assessed on the discrimination of hidden figures and other visually guided behaviors to determine whether such insults produce deficits like those that follow lateral striate lesions in monkeys. Cats with destruction limited to the representation of central vision (Group M) were impaired at discriminating patterns complicated by extraneous cues, but they were less impaired than cats with more complete lesions (Group MS). The deficit was not a general one in visual learning since animals in both Groups M and MS learned simple pattern discriminations as rapidly as controls. It is suggested that the loss of geniculocortical functions representing central vision produces similar deficits m cats and monkeys but that to have this effect in cats, damage must extend beyond area 17.

Behavioral effects of early rearing conditions and neonatal lesions of the visual cortex in kittens.

“…This explanation of our findings is not completely satisfactory, however, since it fails to explain why rats with neonatal lesions of the visual cortex choose the shallow side of a visual cliff reliably more often than rats with comparable lesions made in adulthood (Bauer & Hughes, 1970;Tees, 1976). In any case, the results from both the pen-reared and the cage-reared kittens confirm the previous findings that relatively complete lesions of the visual cortex impair performance of cats on the version of the visual cliff used in the present study whether the lesions are made in infancy (Cornwell et al, 1978) or in adulthood (Cornwell, Overman, & Campbell, 1980;Cornwell et al, 1976).…”

“…Stimuli can be made more or less salient by the number and prominence of potentially distracting background stimuli. Adding irrelevant borders to the stimuli, for instance, greatly increases the difficulty of discriminating an upright from an inverted triangle for cats with incomplete damage to the visual cortex (Cornwell et al, 1980). In the present experiment, all stimuli were present in room illumination, and no attempt was made to have only the stimuli themselves lighted.…”

Selective sparing after lesions of visual cortex in newborn kittens.

“…Irrelevant contours might interfere most with pattern discrimination when the masking is in the same spatial frequency range as the patterns to be discriminated. The pattern stimuli and the irrelevant contours used in this study and in our previous work were similar in spatial frequency, and in each of those studies, the irrelevant contours caused serious defects, even by cats with subtotal damage of Areas 17 and 18 (Cornwell et al, 1980;Cornwell et al, 1978;Cornwell & Warren, 1981). Kriiger et al (1986) obtained similar results when cats with relatively complete lesions of Areas 17 and 18 were required to discriminate small geometric patterns in the presence of broadband or medium-frequency Gaussian noise.…”

Differential sparing of depth perception, orienting, and optokinetic nystagmus after neonatal versus adult lesions of cortical areas 17, 18, and 19 in the cat.

“…Visual tracking. Forty cats were assessed .for visual tracking of a tassel of yarn using a procedure described previously (Cornwell, Overman, & Campbell, 1980). The performance of 10 sham-operated controls was compared with that of 19 cats subjected to one-stage neonatal lesions of areas 17,18, and part of 19 on P3 or P4 (Group S3) and 13 cats with lesions of areas 17, 18, and part of 19 made in adulthood (Group S180).…”