Improving auditory access to low imageabilty words by embedding them in imageable semantic-syntactic contexts in a case of deep phonological dysphasia

Abstract

Deep dysphasia is a relatively rare subcategory of aphasia, characterized by word repetition impairment and profound auditory-verbal short-term memory (AVSTM) limitation. Accuracy of word repetition is better for words than nonwords (lexicality effect) and better for high-image than low-image words (imageability effect). The cardinal feature of deep dysphasia is the occurrence of semantic errors in single word repetition (Howard & Franklin, 1988). Phonological dysphasia shares all of these features except that semantic errors in repetition appear in repetition of multiple words and sentences. Thus, it has been proposed that these two ‘syndromes’ are not distinct, but actually are based on an impairment of auditory-verbal STM that can vary by severity, leading to deep dysphasia when severe and phonological dysphasia when mild (Martin, Saffran & Dell, 1996; Ablinger, Ablel & Huber, 2008). First, we report a single case treatment study of a person whose pattern of word repetition performance was consistent with the continuum of phonological-deep dysphasia: poor repetition of nonwords, imageability effects in repetition of single and multiple words and semantic errors in repetition of multiple word utterances. Differences in processing abstract (i.e., low imageability) versus concrete (i.e., high image) have been considered recently in aphasic treatment protocols (Kiran, Sandberg & Abbott, 2009). Here we test the effects of a theoretically motivated treatment that manipulates the semantic cohesiveness of low imageability (i.e., abstract)-low frequency (LI-LF)words to improve access to and short-term retention of LI words in deep-phonological dysphasia. Following presentation of the treatment case study, we describe an experimental protocol to determine if this approach of increasing imageability of abstract words through syntactic and semantic contexts can be extended to other individuals who present along the deep--phonological dysphasia continuum