title: Effects of kainic acid and radiofrequency lesions of the pulvinar on visual discrimination in the monkey.
abstract: Monkeys with thermocoagulation or kainic acid lesions of the pulvinar and unoperated control monkeys were tested in two tasks: pattern discrimination retention and color discrimination learning in which the stimuli were located at the response sites or were separated spatially from them (S-R separation). The monkeys with kainic acid pulvinar lesions were mildly impaired in retention of the pattern discrimination, but were unimpaired in the color discrimination tasks with or without the S-R separation. The monkeys with thermocoagulation lesions, like monkeys with superior colliculus lesions in a prior study, were severely impaired in performing one of the color discrimination tasks with S-R separation. These findings suggest that: (a) the inferior pulvinar, unlike the superior colliculus, does not contribute to the performance of discriminations involving S-R separation; and (b) corticotectal projections traversing the pulvinar and destroyed by the thermocoagulation lesions are crucial to the performance of discriminations involving S-R separation. The results of an earlier experiment also suggested that interruption of corticotectal fibers passing through the pulvinar impairs performance in another task sensitive to superior colliculus lesions--spatial localization of light flashes. Thus, corticotectal projections may be crucial for the contribution of the colliculus to performance in a variety of visual tasks.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D003118:Color Perception / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology*; D008252:Macaca fascicularis; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011759:Pyrrolidines / Q000494:pharmacology*; D013477:Superior Colliculi / Q000502:physiology; D013787:Thalamic Nuclei / Q000187:drug effects / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology
chemical_list: D011759:Pyrrolidines; D007608:Kainic Acid