Specific Semantic Word Categories in Aphasia

Abstract

This study was prompted by clinical observations that aphasic defects in naming or in auditory comprehension of words are sometimes disproportionately severe for certain semantic categories or are even confined to one category. The question was posed as to whether any regularities existed between such circumscribed deficits and other factors in aphasia. One hundred thirty-five aphasics were tested for their proficiency in naming objects, colors, numbers, letters, and actions, and for their auditory comprehension of words in these categories, plus the additional categories of “geometric forms” and “body parts.”. It was found that “Objects” were the most difficult category to name, but one of the two easiest to comprehend auditorily. In contrast, “Letters” were the easiest category for naming, but the most difficult for auditory comprehension. A further analysis by diagnostic class of aphasia was based on data from 72 patients, who had been classified as either Broca's, Wernicke's, or amnesic aphasics. It was found that for all classes of aphasics, comprehension of object names was most frequently the easiest receptive category and comprehension of letter names most frequently the hardest. Body part comprehension was most frequently depressed among Wernicke aphasics, relative to the other categories. The most striking distinction between diagnostic classes emerged in relation to the naming of objects and letters. It was the Wernicke's aphasics and amnesic aphasics whose scores accounted for the previously observed superiority of letternaming and the inferiority of object-naming. The Broca's aphasics, in contrast, showed no significant differences between the various semantic classes in their naming proficiency. It is concluded that the pattern of differences in naming and auditory discrimination among words of various semantic categories varies predictably with the major clinical types of aphasia.