Assessing phonetic and phonological working memory precision

Only few studies have investigated auditory-verbal working memory (WM) precision, which is the resolution at which verbal items are maintained in WM. The aim of this study was to explore WM precision using a phonetic-phonological similarity gradient in a recognition task. Lists of non-words were presented auditorily. After each list, a probe non-word was presented, and participants had to decide whether or not that item had been in the list. At the phonetic level, we modified the onset of the initial phoneme of one of the memoranda to render it phonetically ambiguous. At the phonological level, probe items differed from the memoranda by close (/p/-/b/) or more distinct (/p/-/t/) phonological contrasts. We observed an influence of both phonetic and phonological contrasts, which furthermore interacted with the serial position of the memoranda. This study suggests that WM precision is influenced by the level of linguistic abstraction and by serial position.