Generalisation and maintenance across word classes: comparing the efficacy of two anomia treatments in improving verb naming

Abstract

Background: Many language treatments have been developed to remediate anomia, a debilitating and pervasive symptom of aphasia. The two major types of anomia treatments, semantic and phonological, have been shown to improve spoken production of trained words. However, generalisation to untrained words has been considerably variable and few studies have examined the improvement of untrained words from a different word class despite the presence of unbalanced noun-verb impairments in the majority of people with aphasia.

Aim: This retrospective study investigated within and between treatment group effects of two anomia treatments (Semantic Feature Analysis, SFA, and Phonomotor Treatment, PMT) on naming of untrained verbs.

Methods & Procedures: The data for this study were retrospectively analysed from a randomised controlled trial with 57 persons with aphasia randomised to one of two treatment groups. Each participant received 56–60 hours of intensively delivered treatment over 6 weeks, with testing before, immediately after, and three months after treatment termination.

Outcomes & Results: There was no significant between-group difference on confrontation naming of untrained verbs immediately post-treatment or three months following treatment termination (maintenance). Significant within-group findings were evident immediately post-treatment for the individuals in the SFA group and at maintenance for the PMT group.

Conclusions: Our results show that neither SFA nor PMT was superior at inducing generalisation effects across word class (i.e. from nouns to verbs). These findings were consistent with the between-group results from the larger randomised controlled trial from which these data are analysed (Kendall, Oelke, Allen, Torrence, & Nadeau, 2018) in that there was no between-group difference in generalization to untrained words that do not share semantic or phonological sequence features. However, the within-treatment group results in the maintenance phase add to evidence from prior studies that Phonomotor Treatment is more likely to facilitate generalisation. Although generalisation to untrained stimuli was minimally maintained after SFA treatment, there was further improvement to untrained exemplars over time following Phonomotor Treatment.