Cross-modal generalization of anomia treatment to reading in aphasia

Abstract

ABSTRACT Background: Generalization of treatment effects is the ultimate goal of therapy. However, treatment generalization across language modalities is not well understood in the aphasia literature and requires further investigation. This work examined the generalization effects of two word retrieval therapies, Phonomotor Treatment (PMT) and Semantic Feature Analysis (SFA), to reading performance in individuals with aphasia. Aims: This cross-modal generalization investigation was motivated by the Primary Systems Hypothesis, which proposes reading ability is related to and dependent upon underlying phonological and semantic abilities. Therefore, this study sought to determine if enhanced phonological or semantic knowledge following anomia treatment could influence reading ability. Methods & Procedures: Reading data collected in a randomized control trial for anomia treatment were retrospectively analyzed. Fifty-eight participants with chronic aphasia were randomly assigned to receive intensive PMT (n = 28) or SFA (n = 30) treatment for 56–60 hours over 6–7 weeks. Reading measures were administered pre-, post- and 3 months after treatment. To identify and compare the extent of treatment generalization to reading, within-group and between-group analyses of variance were performed. Outcomes & Results: On average, participants in both groups showed positive changes in reading. The PMT group demonstrated significantly improved reading of regularly and irregularly spelled words. The SFA group showed significant gains in reading of regularly spelled words and sentence-level reading comprehension. No statistically significant differences in oral reading or reading comprehension were found between the groups before or after therapy. Conclusions: These preliminary findings support the Primary Systems Hypothesis and suggest a link between reading ability and phonological and semantic abilities. Results show that one anomia treatment was not superior to the other and the positive influence of both PMT and SFA suggests that reading might be enhanced via intensively delivered treatments that focus on the underlying phonological or semantic impairment. Further investigations of cross-modal treatment generalization are needed to help better understand this relationship between word retrieval and reading and its implication for aphasia treatment.