Effects of Semantic Context on Criterion-learning Naming Treatment in Aphasia

Overview

Aphasia is a disorder of spoken and written language, most commonly following a stroke. It is estimated that between 2.5 and 4 million Americans are living with aphasia today. A common problem in aphasia involves difficulty retrieving known words in the course of language production and comprehension. The overarching goal of this project is to develop and test early efficacy, efficiency, and the tolerability of a lexical treatment for aphasia in multiple-session regimens that are comprised of retrieval practice, distributed practice, and training dedicated to the elicitation of correct retrievals. The aim of this work is to add to and refine the evidence base for the implementation and optimization of these elements in the treatment of production and comprehension deficits in aphasia, and make important steps towards an ultimate goal of self-administered lexical treatment grounded in retrieval practice principles (RPP) to supplement traditional speech-language therapy that is appropriate for People with Aphasia (PWA) from a broad level of severity of lexical processing deficit in naming and/or comprehension. This project cumulatively builds on prior work to develop a theory of learning for lexical processing impairment in aphasia that aims to ultimately explain why and for whom familiar lexical treatments work, and how to maximize the benefits they confer.

This study examines a retrieval practice-based naming treatment termed criterion learning. In criterion learning, each item's assigned criterion level dictates the number of times that item is correctly retrieved before it is dropped from further training within a session. Criterion learning optimally incorporates potent learning experiences, including spaced retrieval practice with emphasis on correct retrievals during training. The present study will provide critical observations for optimizing criterion learning for treating word processing deficits in people with aphasia. This study will recruit 12 community-dwelling individuals with aphasia, who will undergo comprehensive neuropsychological characterization. Subsequently, participants will engage in an experimental treatment designed to promote improvements in word retrieval deficits. This study will examine whether making retrieval practice more effortful by increasing semantically-driven lexical competition enhances naming treatment benefit in a multiple-session naming treatment. This involves training items amidst related (e.g., for "dog," horse, cow, zebra) or unrelated items (e.g., for "dog," ambulance, pencil, rose). Each PWA will complete multiple training/test rounds--a round refers to the two training sessions separated by one or more days, and a retention test for those items. In some sessions, a desk-mounted eyetracker will be used to track eyegaze patterns as participants name pictures.