The aphasics' identification of a superordinate's referents with basic object level and subordinate level terms.
In a hierarchically-structured semantic field, words at different hierarchical levels exhibit different scopes of reference. The possibility that fluent aphasics could refer more accurately with a subordinate level term than a basic object level term, due to its narrower scope of reference, was investigated in this study. Non-fluent aphasics, fluent aphasics, subjects with insult lateralized to the right hemisphere, and control subjects were asked to name instances of 20 familial superordinates (e.g., vegetables). Responses which were basic object level names (e.g., squash) and those which were subordinate level names (e.g., acorn squash) were analyzed separately. Aphasics produced fewer responses overall than non-aphasic subjects, although they produced larger proportions of subordinate level responses than non-aphasics. An analysis of the basic object level names revealed that the non-fluent aphasics produced the most highly representative instances of a superordinate, while the fluent aphasics provided the least representative instances, often naming out-of-set referents. In marked contrast, an examination of the subordinate level responses revealed that the fluent aphasics were as accurate as any other subjects in naming out-of-set referents. In marked contrast, an examination of the subordinate level responses revealed that the fluent aphasics were as accurate as any other subjects in naming instances of a superordinate. These data, in conjunction with the findings of other recent studies, suggest some to the skills which the fluent aphasics may successfully bring to bear in their attempts to refer with a word.