Graduation Year


Document Type




Degree Granting Department

Communication Sciences and Disorders

Major Professor

Jacqueline H. Hinckley

Co-Major Professor

Stefan A. Frisch


aphasia, atypicality, complexity account, personal relevance, semantic treatment


This study investigated the influence of semantic complexity treatment in individuals with fluent aphasia on discourse performance. Semantic treatment is an effective way to improve semantically based word retrieval problems in aphasia. Treatment focused on the semantic application of the Complexity Account of Treatment Efficacy (CATE) (Thompson, Shapiro, Kiran, & Sobecks, 2003) promotes training of complex items resulting in generalization to less complex, untrained items. In addition, research has shown that the personal relevance of treatment material can increase treatment efficacy. This study investigated the effect of semantic treatment of atypical personally relevant items among individuals with aphasia on discourse performance.

Two treatment phases were applied to examine the influence of personally relevant and non-relevant treatment material on discourse performance. In addition, generalization from trained atypical items to untrained typical items was investigated. Methods and procedures were partially replicated from Kiran, Sandberg, & Sebastian (2011) examining semantic complexity within goal-derived (ad hoc) categories. Three participants with fluent aphasia were trained on three semantic tasks including category sorting, semantic feature generation/selection, and Yes/No feature questions. A generative naming task was used for probe data collection every second session. Stimuli consisted of atypical items only.

The hypothesis that semantic complexity training of personally relevant items from ad hoc categories will produce greater generalization to associated, untrained items than training of non-relevant items and consequently increase discourse performance was not supported. The findings revealed a failure to replicate the magnitude and type of improvements previously reported for the typicality effect in generative naming. Clinical significance was found for personally relevant and non-relevant discourse performance. However, no consistent pattern was found within and across participants. In addition, effect size for generalization from trained atypical to untrained typical items was not significant.

Limitations of this study lead to future directions to further specify participation selection, such as cognitive abilities, procedural changes, and the inclusion of discourse performance as an outcome measure. Overall, the results of this study provide weak support for replicating semantic treatment of atypical exemplars in ad-hoc categories and hence demonstrate the critical role of replication across labs to identify key issues in the candidacy, procedures, and outcome measurement of any developing treatment.