University of Washington
In a recent review of anomia management, Maher & Raymer reported that 30% of aphasia intervention research from 1946 to 2001 focused on naming; however, "despite this proliferation of case reports and small group studies, there is still no clear agreement on how best to manage these deficits" (Maher & Raymer, 2004, p. 13). The inconsistency of acquisition, maintenance, and generalization effects observed across participants and types of treatment protocols is likely to stem from an inadequate knowledge base about how subject and treatment variables influence learning.
One treatment variable that has received increasing attention over the past two or three years is treatment intensity. Principles of neurobiological learning across both animal and human research suggest that the intensity of treatment is a significant factor for learning. Additional research exploring experience-dependent neural plasticity involved in memory and learning indicates that a large number of trials per session are required to elicit behavioral and/or neural change. Despite a considerable amount of literature examining overall treatment intensity, data are not available regarding the frequency (i.e., stimulus dosage) of treatment at which individuals with aphasia will maximally benefit.
A single-subject A-B design with replication across four individuals with aphasia and one healthy non-brain injured gender-matched control participant was used to assess the influence of repeated attempts at picture-naming, coupled with repeated exposure to hearing and reading target words, on the acquisition and maintenance of trained stimuli, and generalization to untrained stimuli. Individuals with chronic aphasia participated in a multi-week repetition priming protocol designed to investigate the influence of stimulus dosage on naming accuracy and latency. Results revealed positive repetition priming effects for trained items across both acquisition and maintenance phases; such positive effects were not observed for untrained stimuli or alternate exemplars. Stimulus dosage manipulations did not consistently influence naming performance for individuals with aphasia.
© 2008 Catherine A. Off