Nonverbal Working Memory as a Predictor of Anomia Treatment Success.

Purpose: The purpose of the study was to determine (a) reliability of the spatial span as a nonverbal working memory (WM) task in individuals with aphasia, (b) whether participation in anomia treatment changed spatial span scores, and (c) the degree to which visuospatial WM predicted response to anomia treatment.
Method: Eight individuals with chronic aphasia were repeatedly assessed on the forward and backward conditions of the spatial span over 4 weeks while undergoing treatment for anomia. Experiment 1 assessed reliability of the spatial span conditions and determined whether span scores changed after beginning anomia treatment. Experiment 2 investigated the spatial span as a predictor of anomia treatment success.
Results: Results of Experiment 1 showed that 7 participants demonstrated stability of the forward condition of the spatial span, and 5 participants demonstrated stability of the backward condition across all sessions (p = .05). No participants showed an effect of aphasia treatment on span performance in either condition. Experiment 2 found that the backward span condition significantly predicted anomia treatment effect size, F(1, 6) = 15.202, p = .008.
Conclusions: Visuospatial WM abilities were highly predictive of response to anomia treatment, supporting an account of WM that includes a central processing mechanism.