Visual recognition in right brain-damaged patients: evidence from a tachistoscopic confrontation naming task.

Right brain-damaged patients performed a confrontation naming task. Pictures were tachistoscopically presented to the right visual field and selected for their high degree of canonicity and name agreement measured in control subjects. Compared to controls, patients exhibited significant errors. Misnamings were mainly perceptual, i.e., visual-semantic or purely visual errors. No evidence of pure semantic error was found. Half of visual-semantic misnamings referred to objects of a different size (scale error) within the correct semantic field. Misnamings are tentatively attributed to a disturbance of the visual-imagistic automatic encoding process at the level of the pictorial data store.