Phonological Production Deficits in Conduction Aphasia

Abstract

The purpose of this chapter is to present, evaluate, and interpret recent investigations of phonemic paraphasia as it is manifested in conduction aphasia (CA). Although phonemic paraphasia has been observed in other aphasic syndromes, it represents the primary linguistic deficit in conduction aphasia. The production model that serves as the primary vehicle for characterizing the phonemic paraphasias in CA is that of Merrill Garrett (e .g., 1988, 1990a). This model has been constructed on the basis of spontaneous speech in which slips-of-thetongue have occurred, and so the spontaneous speech of CAs is considered . However, because much of the data on phonemic paraphasias in CA has been garnered at confrontation testing in neuropsychological and clinicallaboratories, I also consider various stimulus-response elicitations collected experimentally . Some of the typical tasks utilized are repetition, object naming, and oral reading. Paraphasic production on these tasks is characterized as well by the Garrett model, with several distinct control factors taken into account, because responding to experimental stimuli is cognitively driven somewhat differently from responding to normal spontaneous speech stimuli in typical discourse settings; that is, the ideational-message level processing is different for spontaneous speaking versus responding on confrontational testing. I also consider the phonemic paraphasias produced in self-repairs of errors, either in spontaneous speech or on confrontation elicitation. Self-repair through self-monitoring has been studied under the heading of sequential phonemic approximation or conduite d'approche. Aphasia researchers have gained a great deal of information on phonemic paraphasia by the analysis of these self-repairs . Thebasic issue addressed, however, is whether and to what extent we can locate some level or levels in the Garrett model that serve to uniquely capture the phonemic paraphasic component in the language of conduction aphasics.