The treatment of an auditory working memory deficit and the implications for sentence comprehension abilities in mild "receptive" aphasia

Background: Theoretical studies have shown that some deficits in verbal short-term/working memory can impact comprehension abilities. Clinicians often suspect that their clients are failing to understand speech because they cannot remember what has been said. Yet there are no reports of how to treat such a problem. Aims: To see if improving the short-term/working memory abilities of a person with aphasia would improve her comprehension at the sentence level. In addition, we sought to explore the issues involved in carrying out research-based therapy in a clinical environment. Methods & Procedures: The memory and language impairments of a person with aphasia were assessed. The memory impairments were then targeted in therapy by requiring the repetition of gradually more demanding sentences. Comprehension itself was not practised at all during therapy. Outcome and Results: Certain aspects of short-term and working memory improved post-therapy, notably an increase in digit span and an ability to repeat more words in sentences. There was a limited generalisation of improvement to comprehension tasks, meaning that the client could understand longer sentences and required fewer repetitions. The existence of possible additional impairments was revealed post-therapy. Conclusions: If memory limitations are causing comprehension difficulty, therapy may need to take the focus away from language and on to short-term/working memory. However, improvement may be limited. In addition, we suggest that within the context of a clinical setting, a reasonable balance between research and therapy can be struck (albeit with some difficulty) if compromises are made.