Dissociations in auditory word comprehension; evidence from nine fluent aphasic patients

Abstract

Traditional aphasia classifications do not allow for a detailed description of auditory comprehension impairments. A cognitive neuropsychological model of lexical processing allows us to distinguish at least 5 different levels of impairment in single word auditory comprehension. It also specifies a more complex relationship between impairments in repetition and auditory comprehension. Nine fluent aphasic patients, with auditory comprehension disorders, were assessed using tests of phoneme discrimination, lexical decision, synonym matching and word and non-word repetition. The results of these tests, as predicted, indicated that there were 5 dissociable levels of impairment, although there was some evidence for interaction between levels. The patients showed qualitative differences between auditory and written comprehension. Four of the patients had impairments in repetition despite having no impairment in phoneme discrimination tests. No two patients showed exactly the same pattern of impairment across all the tests administered.