Verb retrieval in fluent aphasia: A clinical study

We are grateful to the three participants and their practice partners, the speech and language therapists who referred participants, and Lizet Van Ewijk who helped with the analyses of the data. The project was funded by a University of Reading Health Research Fellowship.

Abstract

Background: Problems with lexical retrieval are common across all types of aphasia but certain word classes are thought to be more vulnerable in some aphasia types. Traditionally, verb retrieval problems have been considered characteristic of non‐fluent aphasias but there is growing evidence that verb retrieval problems are also found in fluent aphasia. As verbs are retrieved from the mental lexicon with syntactic as well as phonological and semantic information, it is speculated that an improvement in verb retrieval should enhance communicative abilities in this population as in others. We report on an investigation into the effectiveness of verb treatment for three individuals with fluent aphasia.

We are grateful to the three participants and their practice partners, the speech and language therapists who referred participants, and Lizet Van Ewijk who helped with the analyses of the data. The project was funded by a University of Reading Health Research Fellowship.

Methods & Procedures: Multiple pre‐treatment baselines were established over 3 months in order to monitor language change before treatment. The three participants then received twice‐weekly verb treatment over approximately 4 months. All pre‐treatment assessments were administered immediately after treatment and 3 months post‐treatment.

Outcome & Results: Scores fluctuated in the pre‐treatment period. Following treatment, there was a significant improvement in verb retrieval for two of the three participants on the treated items. The increase in scores for the third participant was statistically non‐significant but post‐treatment scores moved from below the normal range to within the normal range. All participants were significantly quicker in the verb retrieval task following treatment. There was an increase in well‐formed sentences in the sentence construction test and in some samples of connected speech.

Conclusions: Repeated systematic treatment can produce a significant improvement in verb retrieval of practised items and generalise to unpractised items for some participants. An increase in well‐formed sentences is seen for some speakers. The theoretical and clinical implications of the results are discussed.

Notes

We are grateful to the three participants and their practice partners, the speech and language therapists who referred participants, and Lizet Van Ewijk who helped with the analyses of the data. The project was funded by a University of Reading Health Research Fellowship.

1. We used three different types of statistical tests suitable for non‐parametric data in our analysis. The McNemar is a version of the chi‐square for within‐subject design. It was used to compare before and after treatment scores, as it has been identified as a suitable test for such data (Pring, 2005) and for repeated measure designs. The Wilcoxon was applied when the sets were related but not dichotomous, so when comparing scores of T1+T2+T3 with scores from T4 or T5. This test was also used for analysis of the latency scores. For the comparison of percentage correct on the noun and verb lists, we used the Mann‐Whitney test, as the sets were independent (and of different size) (Perry, 1995). We are aware that there are differing opinions about the use of statistics in single‐subject design studies, with some researchers claiming that the use of statistics is inappropriate while others insist that “improvement” can only be claimed when the change is statistically significant (Pring, 2005; Thompson, in press). We are unable