Dissociations of language functions in aphasics with speech automatisms (recurring utterances)

The linguistic performance of 27 aphasics with frequent production of non-lexical speech automatisms (recurrent utterances; e.g. do-do-do...) in spontaneous speech was investigated. Of the 26 patients examined with the Aachen aphasia test (AAT), 24 cases suffered from global aphasia, one from Broca's aphasia, and one was not classifiable but most resembled the fluent types as Wernicke's or conduction aphasia. While most patients were severely impaired in language comprehension, a subgroup showed impairments on a moderate level. In four cases clear dissociations between oral and written output performance were found. Only one patient, and very rarely so, interspersed his written output with his speech automatism. Analysis of written output within the theoretical framework of the logogen model provided evidence for the possibility of a partially intact phonological system in patients with speech automatisms. Results are interpreted as supporting a sub-phonemic hypothesis of the generation of non-lexical speech automatisms.