Criterion-learning Based Naming Treatment in Aphasia

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. By examining scheduling and dosing parameters, and feasibility of at-home delivery, the present study will provide critical observations for optimizing criterion learning for treating word processing deficits in people with aphasia. This study will recruit 90 community-dwelling individuals with aphasia, who will undergo comprehensive neuropsychological characterization which may include neuroimaging. Subsequently, participants will engage in treatments designed to promote improvements in word retrieval deficits. To advance theoretical and clinical aims, depending on outcomes of neuropsychological characterization, participants may be invited to complete one or more experiments.

Experiment 1 will examine naming mastery of personally-relevant, functional vocabulary for PWA as a function of per-item naming practice dosage (i.e., criterion-level) and number of training sessions. Each participant will take part in a multi-session naming treatment study requiring completion of five training sessions generally separated by one-week. A retention test of naming performance will be administered approximately one week following the final training session. The first trial per item in sessions following the initial session serves as a one-week test of retention of prior training. Analyses will identify the item-dosage and session-dosage that most efficiently confers the highest naming mastery of treated items at a one-week retention interval.

Experiment 2 will adopt the most efficient item-dosage/session-dosage schedule identified in Study Arm 1. In Study Arm 2, each PWA will complete an in-lab module, and an at-home module, with each module preceded by a baseline phase and followed by naming post-tests. Different sets of personally-relevant, functional items will be assigned to the two modules for each PWA. A retention test will be administered in the lab after the final training session in each module, and each test will include a set of untreated items, to probe a potential generalized benefit of the treatment. To assess individual benefits, improvement on the retention test will be calculated relative to baseline in each module.

Experiment 3 will examine whether making retrieval practice more effortful by increasing semantically-driven lexical competition enhances naming treatment efficacy 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 approximately 1-week, and a retention test for those items.

Experiment 4 will examine transfer from two types of naming treatment to word comprehension performance. Each PWA will perform naming treatment in one session at different dosages with a retention test of comprehension performance administered approximately one week and one month following treatment. Main outcomes of interest will be degree of transfer of each type of naming treatment to comprehension performance.

Eligibility Criteria:
Inclusion Criteria:

* English as a native or primary language
* Adults with stroke who are at least 6 months post-onset

Exclusion Criteria:

* History of comorbid neurological diagnoses, such as Multiple Sclerosis or Parkinson's Disease
* History of a learning disability that significantly impacted language development, such as developmental language disorder