Measuring gains in connected speech following treatment for word retrieval: a study with two participants with primary progressive aphasia

Abstract

Background: The aim of lexical retrieval treatment for people with anomia is not just to improve accessibility of lexical items for confrontation naming but to carry over this improvement to communicative situations. However, there is no consensus on what measures are the most suitable to evaluate whether such changes have occurred. Anomia is one of the core presenting symptoms for people with primary progressive aphasia (PPA), yet while there is increasing evidence for the efficacy of word retrieval treatments in PPA, there is minimal information about how improvements in picture naming transfer to connected speech.

Aims: This paper evaluates a word retrieval treatment targeting personally relevant words conducted with two people with PPA, focusing on patterns of generalisation.

Methods & Procedures: The study is a single-blind single-case experimental design. Participants and primary communication partners identified words related to two topics that are personally relevant for conversation. Participants completed three baseline and one or two post-test measures of their ability to produce these words in picture naming and a structured interview. Therapy activities lasting 10–15 min/day were carried out over a 2-week period at home, with participants viewing a picture of each target word on a computer screen together with its written and spoken name and repeating/reading the name. Half of the words from one topic were treated; a matched set of words from the treated topic and words from the untreated topic served as controls to allow us to assess generalisation within and across topic.

Outcomes & Results: At post-test, the participants’ naming improved for the treated items, showing generalisation to different pictures of these items. There was neither generalisation to untreated items, nor to retrieval of the same words in a structured interview.

Conclusions: Further research is required to understand the limits and the potential of word retrieval treatments to improve conversation in both acute-onset and progressive aphasia.

Keywords:

• connected speech
• conversation
• generalisation
• progressive aphasia
• frontotemporal dementia
• Alzheimer’s disease

Notes

1. Comprehensive Aphasia Test naming items are of much higher frequency than items in the Graded Naming Test.

2. Overall percentage correct for each participant reflects their anomia relative to the items selected as personally relevant for them. Different items for each participant mean that success is not directly comparable across individuals.

3. Note that the lack of a significant improvement over the study as a whole in cases with progressive aphasia may not mean that there has been no improvement. If the trajectory would have been downward prior to therapy, then no change across the study may be a positive outcome of treatment (Rapp & Glucroft, 2009).

4. As there were 10 analyses in each condition in the analysis of connected speech, we only consider significant values where p > .005.

5. We also asked DQI to imagine walking along a beach and to describe what she saw there, but this did not appear to result in retrieval of more treated or untreated words related this topic.

Additional information

Funding

This project was supported by an Alzheimer’s Australia Research Hazel Hawke Research Grant to Karen Croot, Lyndsey Nickels, and Cathleen Taylor, a Visiting Fellowship at the Centre for Advanced Studies at Ludwigs Maximillians Universitaet Munich held by Karen Croot, a grant from the Dr. Werner Jackstaedt-Stiftung awarded to Stefanie Abel, and an Endeavour Research Fellowship to Inga Hameister. Lyndsey Nickels was funded by an Australian Research Council Future Fellowship [grant number FT120100102].