Novel Word Learning as a Treatment of Word Processing Disorders in Aphasia

Abstract

Research suggests that novel word learning tasks engage both verbal short-term memory (STM) and lexical processing, and may serve as a potential treatment for word processing and functional language in aphasia (e.g., Gupta, Martin, Abbs, Schwartz, Lipinski, 2006; Tuomiranta, Grönroos, Martin, & Laine, 2014). The purpose of this study was to gain support for the hypotheses that novel word learning engages verbal STM and lexical access processes and can be used to promote improvements in these abilities in treatment of aphasia. We used a novel word learning task as a treatment with three participants: KT, UP, and CN, presenting with different types and severities of aphasia and predicted that treatment would result in (1) acquisition of trained novel words (2) improved verbal STM capacity and (3) improved access to and retrieval of real words. Twenty novel words were trained for 1 hour x 2 days/week x 4 weeks. Language and learning measures were administered pre- and post-treatment. All three participants showed receptive learning and some improvement on span tasks, while UP and CN demonstrated some expressive learning. KT also improved in performance on the Peabody Picture Vocabulary Test and the Philadelphia Naming Test. UP showed significant improvement on proportion Correct Information Units (CIUs) in discourse. CN showed some minimal improvement in narrative production for proportion CIUs and proportion of closed class words. These findings support that novel word learning treatment, which engages verbal STM processes and lexical retrieval pathways, can improve input lexical processing. Theoretically, this study provides further evidence for models that propose common mechanisms supporting novel word learning, short-term memory, and lexical processing.