Psychophysical and neurophysiological investigations of the effects of early visual deprivation in the cat.

Cats can locate objects with their monocularly deprived eye best in the monocular segment of their visual field. In contrast they show a marked deficit towards the midline and an almost total failure in the binocular segment contralateral to the deprived eye. This correlates well with the relative frequency of units in the superior colliculus activated by that eye. The performance of the cat in a pattern discrimination task is three times better with the normal eye than with the deprived eye if the patterns have to be detected on a background of visual noise. This correlates well with the loss of units in the visual cortex activated by the deprived eye. There is no loss of visual acuity in the units in lamina A of the lateral geniculate body, but in lamina A1 visual acuity is reduced to half the normal value due to monocular deprivation.