Working memory and sentence production

What is it about?

This study shows that verbal working memory (WM), that is, our ability to store and process a small number of verbal items (e.g., words or numbers) for a limited amount of time (i.e. for a few seconds), impacts on our ability to produce grammatically correct sentences. In particular, this study focused on Greek and found that verbal WM plays a role in grammatical ("morphosyntactic") phenomena such as Tense/Time Reference (e.g., "Yesterday he went to the cinema" and not "Yesterday he will go to the cinema") and Aspect (e.g., "While I was writing a letter, the phone rang" and not "While I wrote a letter, the phone rang"). In contrast, the results suggest that verbal WM does not affect subject-verb Agreement (e.g., "He walks to work every day" and not "He walk to work every day"). Interestingly, the same interaction between verbal WM and grammatical/morphosyntactic phenomena was found in eight individuals with agrammatic aphasia (i.e., individuals who suffered a stroke, which in turn gave rise to problems with language production and grammar) and in 103 neurologically healthy individuals. Importantly, this interaction shaped the pattern of morphosyntactic performance exhibited by both groups, which had better performance on subject-verb Agreement than on Time Reference/Tense and Aspect, and better performance on Time Reference/Tense than on Aspect.

Why is it important?

This is one of the few studies that explored the relationship between working memory (WM) and morphosyntactic production. The most important finding was that verbal WM is critically involved in morphosyntactic production, differentially affecting the production of verb-related morphosyntactic categories and shaping the pattern of morphosyntactic impairment in persons with agrammatic aphasia and healthy older adults.