Multi-step treatment for acquired alexia and agraphia (Part I): efficacy, generalisation, and identification of beneficial treatment steps

ABSTRACT

Reading and writing impairments are common in individuals with post-stroke aphasia. Treatment typically aims to improve the function of one of these modalities by strengthening aspects of either lexical or sublexical processing. In the present study, eight adults with acquired alexia and agraphia were administered a comprehensive treatment targeting specific lexical and sublexical processes underlying reading and/or writing. Two participants were trained in reading and six were trained in writing. Throughout treatment, reading and writing accuracy were monitored for trained items, as well as untrained but orthographically and semantically related items. Linear mixed effects models indicated that the most substantial gains were made on trained items in the trained modality; generalisation to trained items in the untrained modality and untrained but related items in both modalities was also observed. Participants improved significantly on a subset of treatment steps intended to address lexical access and representations, sublexical conversion mechanisms, and the graphemic and/or phonological buffer processes in both modalities. These results demonstrate the efficacy of a novel, comprehensive treatment protocol and suggest that targeting multiple reading and writing processes in conjunction may facilitate widespread generalisation.

KEYWORDS:

• Alexia
• agraphia
• aphasia
• treatment
• therapy
• dyslexia/dysgraphia

Acknowledgements

First and foremost, the authors thank the individuals who participated in this study; without their time and commitment, none of this work would have been possible. We also thank the members of the Aphasia Research Laboratory for their support throughout the development and execution of this study and Gheorghe Doros and Stefano Cardullo for their consultation on statistical analyses. Finally, we thank Boston University’s Sargent College for supporting this study through the Dudley Allen Sargent Research Fund.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Jeffrey P. Johnson http://orcid.org/0000-0003-4269-3098

Katrina Ross http://orcid.org/0000-0003-2071-6033

Notes

1 Note that P4’s alexia diagnosis was based on a limited number of productions due to numerous non-responses to oral reading items at baseline. This was likely due to moderate-severe apraxia of speech.

2 The majority of words included in participants’ trained sets were regularly spelled; however, the criteria of each trained word having an orthographic neighbour and semantic associate, as well as balancing all sets for letter length and frequency, were prioritised; thus, in some cases, irregularly spelled words were trained (e.g., blood).

3 Steps 1 and 4 were eliminated because participants P1 – P5 found them to be extremely easy even at the beginning of treatment, suggesting they did not offer substantial therapeutic value. Additionally, the processes they were intended to target (lexical and semantic access/representations) were addressed by other steps in the protocol (e.g., steps involving repeating/copying the target and semantic feature analysis).

Additional information

Funding

This work was supported by the Dudley Allen Sargent Research Fund, College of Health & Rehabilitation Sciences: Sargent College, Boston University.