The processing of negative sentences in fluent aphasics: semantic and pragmatic aspects.

This paper examines the processing of negative sentences with respect to their truth value in fluent aphasic subjects. Three groups of 25 subjects each (men and women) were studied: the first group consisted of fluent aphasics, the second consisted of right temporal lobe-damaged subjects, and the third of normal subjects. An experiment of sentence verification was carried out. A quantitative study of reaction time (RT) and a qualitative study of the types of answers were carried out. The results show that the fluent aphasics were impaired in their logical-semantic processing of negative sentences and showed a predilection for the affirmative in answering strategies. The right temporal lobe-damaged subjects showed differences only in respect to the normal subjects in the RT, but not in answering strategies. The results suggest that in Wernicke's Aphasics there is a tendency to substitute a type of contextual-pragmatic processing for the logical-semantic processing.