The fluency-non fluency dimension in the classification of aphasic speech.

Summary In this study, we have investigated whether the fluency-non fluency dimension of spontaneous aphasic speech can be confirmed by mathematical analysis. The speech production of 47 unselected aphasic patients was rated according to criteria similar to those proposed by Benson (1967). A cluster analysis in two-dimensional as well as in ten-dimensional space yielded two distinct groups, corresponding to the clinical syndromes of fluent and non fluent aphasia. Thus, it was demonstrated that this classification of spontaneous aphasic speech reflects naturally occurring differences in language behavior. A tentative rank order of variables according to their discriminating power was computed.