Cognitive distancing in mediated categorization in aphasia.

Individuals with fluent and nonfluent aphasia and a matched group of aged normal subjects participated in mediated categorization tasks dealing with two levels of cognitive distancing. Moreover, the categorization tasks entailed the utilization of focal and peripheral exemplars. Fluent aphasic subjects had significantly more difficulty than nonfluent aphasic and normal subjects. All subjects had significantly more difficulty with pictures than actual objects. Peripheral exemplars were used less often than focal exemplars. It was spesculated that some of these results may reflect a degenerative process of aging.