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The effect of cortical and tectal lesions on the visual fields of binocularly deprived cats
Author(s) -
Sherman S. Murray
Publication year - 1977
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.901720204
Subject(s) - cats , superior colliculus , tectum , visual field , superior colliculi , biology , neuroscience , anatomy , cortical blindness , visual cortex , optic chiasm , visual system , optic nerve , midbrain , medicine , blindness , central nervous system , optometry
The visual fields of seven cats raised with binocular lid suture were measured before and after various neural lesions. Each of the cats preoperatively responded with each eye to stimuli from 90° ipsilateral through to the midline. A transection of the optic chiasm rendered one cat bline on the visual field tests. Large bilateral occipito‐temporal cortical ablations (4 cats) did not measurably affect orienting responses or the extent of visual field. Unilateral occipito‐temporal cortical ablations (2 cats) also had no affect on the visual fields, but subsequent ablations of the contralateral superior colliculus produced permanent blindness in the hemifield contralateral to the ablated tectum. These two cats also were apparently blind with the eye contralateral to the ablated tectum; but with the other eye, the cats retained their preoperative orienting responses. These data are consistent with the hypothesis that, with early binocular deprivation, cats develop dependence upon retinotectal and not thalamocortical pathways for visually guided orienting behavior.