title: Pre-lexical disorders in repetition conduction aphasia.
abstract: At the level of clinical speech/language evaluation, the repetition type of conduction aphasia is characterized by repetition difficulties concomitant with reduced short-term memory capacities, in the presence of fluent spontaneous speech as well as unimpaired naming and reading abilities. It is still unsettled which dysfunctions of the pre-lexical processing stage of spoken word recognition contribute to this syndrome and whether there is any relevant top-down impact of the mental lexicon upon the phonetic/phonological level of speech perception. In order to further specify the underlying pathomechanisms, a comprehensive battery of psycholinguistic tests was applied to a patient suffering from repetition conduction aphasia. The obtained results point at a pre-lexical disorder in this subject. To further specify the assumed pre-lexical dysfunction, computer simulations of single-word processing, based upon an interactive activation model (IAM), were conducted. An attenuation of the features-to-phonemes inhibition value was found to simulate the observed profile of psycholinguistic deficits. Conceivably, these pre-lexical disorders interfere with the task-dependent adjustment of the temporal windows of signal analysis, giving rise to compromised sequencing of auditory-verbal information.
authors.affiliation: Graduate School of Neural and Behavioural Sciences, University of Tübingen, Osterbergstr. 3, D-72074 Tübingen, Germany. ksidiros@web.de
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Sidiropoulos
authors.forename: Ria
authors.initials: R
authors.lastname: de Bleser
authors.forename: Hermann
authors.initials: H
authors.lastname: Ackermann
authors.forename: Bruno
authors.initials: B
authors.lastname: Preilowski