Neuropsychological demonstration of splenial interhemispheric disconnection in a case of "optic anomia".

A patient is described whose neuropsychological deficit corresponded to the notion of "optic aphasia" or, better, optic anomia. The functional deficit was undirectional, i.e. there was a severe impairment in the naming of visually presented stimuli without impairment in the comprehension of the corresponding names. The splenial disconnection was demonstrated by intact cross modal matching within the right hemisphere as well as preserved left-handed tactile naming, which is processed via mid-callosal pathways. The psychological interpretation is discussed in terms of visual and tactile semantics, considering also the presumably diffuse cerebral organization of semantic fields.