Inner Speech Can Predict Naming Treatment Outcomes in Aphasia: A Pilot, Single-Subject Design Study

This single-subject design study examined whether self-reported inner speech (IS)-the subjective experience of retrieving a word internally-can predict item-level outcomes in a cueing-based naming treatment for individuals with poststroke aphasia.

Five adults with chronic, poststroke aphasia completed an IS self-report task and naming task to identify appropriate treatment stimuli in two categories: successful IS (sIS) and unsuccessful IS (uIS). Participants then completed 2 weeks of hierarchical, cueing-based naming treatment targeting both sIS and uIS items. Treatment effects were analyzed using Tau U and mixed-effects models, with additional insights from visual analysis of individual performance.

In four of five participants, naming accuracy improved significantly for sIS items but not for uIS items. The participant who did not show treatment-based learning had the most severe aphasia and apraxia of speech among the group. Mixed-effects models confirmed that self-reported IS significantly predicted posttreatment naming accuracy, even when controlling for aphasia severity and baseline naming performance. The relationship between self-reported IS and naming accuracy also changed over time, as naming accuracy for sIS items increased to more closely align with participants' initial reports of sIS.

Self-reported IS can serve as a clinically useful predictor of naming treatment outcomes in some individuals with aphasia. These findings support our hypotheses and suggest that IS can be a useful tool for guiding treatment stimulus selection and monitoring change during naming therapy. Future research should continue to explore individual variability in the relationship between IS and naming treatment response.

https://doi.org/10.23641/asha.31865308.