One of the most common and debilitating features of aphasia is an impairment in ability to retrieve words, whether it involves naming seen objects, or producing nouns, verbs and other words conveying meaning in spontaneous propositional speech. The long-term goal of this line of research is to establish an effective, viable, evidence-based treatment program for word retrieval deficits in persons with acquired aphasia from stroke. The short-term goal, and focus of this project, is to conduct a final phase II trial that tests the efficacy of an experimental treatent (called phonomotor) against customary and usual treatment (i.e. semantic-based therapy) for anomia in aphasia. In the context of a 2-armed control trial, we propose to deliver 60 total hours of therapy to 80 individuals who have suffered a left hemisphere stroke and exhibit aphasia with significant anomia. Effects of treatment acquisition and generalization will be measured at 3 time points (immediately, 3-months and 1-year post treatment termination). The primary aim will address between group differences of confrontation naming performance of untrained nouns at 3 months. Secondary questions will address generalization of treatment to measures of ecologic validity and discourse production. Through a series of phase I and phase II trials, we have shown that intensively delivered phonomotor treatment not only improves confrontation naming performance on trained words but, as predicted by the theory motivating it, importantly achieves generalization to naming of untrained words, some aspects of discourse production, and indicators of quality of life. The treatment program is motivated by a connectionist model of phonology (Nadeau, 2001; Nadeau, 2006, Nadeau, 2012) and by a two level interactive model of language (Dell, 1987). The theoretical foundation for the phonomotor treatment is as follows: through the systematic training of phonemes (sounds) and phoneme sequences, the neural connectivity supporting phoneme sequence knowledge will be enhanced. Because these sound sequences provide the basis for the words that represent concepts, through bidirectional spread of activation among and between linguistic levels, generalization from treating phonemes can be expected to improve naming of untrained words and discourse production, both immediately after treatment and continued beyond treatment termination.
The World Health Organization has deemed stroke a worldwide health problem based upon its high prevalence, associated disability, and the burden it places on the individual, community and society (Janca et al, 2000). A common sequelae of left-hemisphere stroke is a language disorder called aphasia. Currently, the behavioral rehabilitation of aphasia is unsatisfactory and this proposal seeks to further develop an aphasia treatment that has high potential for improving the daily communicative lives of stroke patients.
