Behavioural and neural changes after a “choice” therapy for naming deficits in aphasia: preliminary findings

Abstract

Background: Anomia, difficulty producing words, is a pervasive symptom of many individuals with aphasia. We have developed a treatment for naming deficits—the Phonological Components Analysis (PCA) protocol—that has proven efficacious in improving word-finding abilities for individuals with post-stroke aphasia.

Aims: The aim of this investigation is to present preliminary findings exploring the potential influence of choice—that is the active engagement of a participant in therapy—on our PCA treatment.

Methods & Procedures: Five individuals with aphasia were treated in one of two conditions—Choice or No Choice. Potential changes in neural activation as a function of the treatment were also investigated. Two individuals (one from each condition) underwent functional MRI (fMRI) pre- and post-therapy.

Outcomes & Results: All the individuals demonstrated a significant treatment effect immediately post-treatment and at a 4-week follow-up and four of the five participants at an 8-week follow-up. Three also demonstrated generalisation to untrained items. Unfortunately, no clear-cut patterns emerged to allow us to make claims about the influence of choice, per se, on the behavioural manifestations of improved naming. Interestingly, the participant from the Choice condition showed neural activation changes post-treatment in frontal and parietal regions that were not evident for the participant in the No Choice condition. Moreover, these changes were accompanied by a larger treatment effect for that individual and generalisation to a novel naming task.

Conclusion: The efficacy of PCA treatment for naming deficits is further supported. In addition, the neuroimaging data suggest the possibility that active engagement of an individual in his/her therapy (in this case choosing phonological attributes of a target word) may exercise executive functions important for success in treating anomia. Also, continued exploration of task factors that may promote even better treatment effects using this protocol is warranted, as is continued investigation of the neural underpinnings associated with treatment effects.

Keywords:

• stroke
• aphasia
• anomia
• rehabilitation
• neuroimaging
• neuroplasticity

Acknowledgements

Portions of this work were presented at the Festival of International Conferences on Caregiving, Disability, Aging and Technology, Toronto, Canada, June 2011 (Rochon, E., Leonard, C., Laird, L., Burianova, H., Soros, P., Graham, S., Grady, C.); at The Heart and Stroke Foundation Centre for Stroke Recovery 9th Annual Scientific Meeting, Toronto, Canada, May 2011 (Rochon, E., Leonard, C., Laird, L., Simic, T.); at the Venice Summer School on Aphasia Rehabilitation, Venice, Italy, September, 2011; and at the 14th International Aphasia Rehabilitation Conference, Montreal, Canada, June 2010 (Leonard, C., Rochon, E., Laird, L). We acknowledge the support of Toronto Rehabilitation Institute, which receives funding under the Provincial Rehabilitation Research Program from the Ministry of Health and Long-Term Care in Ontario. We thank the MRI technologists and Caron Murray at Sunnybrook Health Sciences Centre for assistance with this experiment. Danna Rybko and Liz Pigott provided valuable assistance on this project. We especially thank the participants for their patience and perseverance, and we thank the referring clinicians at the Aphasia Institute and the York-Durham Aphasia Centre.

Notes

1. P2 had only 21 target words as he did not have enough words in error at baseline.

2. The responses used to represent the rhyming words were identified in a norming study of 10 healthy adults as the one that rhymed best.

3. We did not compare performance on treated versus untreated items because of a confound related to the untreated items. Many of the items in the untreated set were ones that the patient was able to name correctly pre-treatment, resulting in artificially inflated pre-treatment scores for untreated items.