Purpose: To optimize aphasia treatment, it is critical to understand the variables contributing to outcomes. For example, treatment factors such as dosage and treatment type have received considerable attention. In this study, we examine the influence of timing, or when treatment occurs. We investigate the impact of naming training in the morning versus the evening with individuals with chronic poststroke aphasia. Prior work with other populations led to our hypothesis that training conducted in the evening would be more durable compared to training in the morning. Method: Thirteen people with chronic aphasia (at least 1 year poststroke) completed an online confrontational naming training followed by three posttests in two temporal conditions, with training occurring in both the morning and evening. The trained stimuli were unique to each participant and selected based on a screener. This resulted in a within-participant comparison of posttraining retention based on the time of training. Participants were characterized based on their results on the Boston Naming Test, the Quick Aphasia Battery, and the Morningness–Eveningness Questionnaire. Results: There was a significant interaction between training schedule and test timing, such that words trained in the evening showed stable retention, whereas words trained in the morning showed significant decline after a 24-hr delay. We did not detect an overall difference in average naming accuracy between evening and morning conditions when collapsed across all time points. Conclusions: These results indicate that the time of day should be considered when administering aphasia treatment. Although proximity to sleep did not result in overall larger accuracy in this sample, the interaction suggests that sleep may still play a protective role in the retention of learned items, which is consistent with findings from studies of sleep and memory in adults without aphasia. Supplemental Material: https://doi.org/10.23641/asha.31152322
Washington et al. (2026) studied this question.