Phonological Similarity Effect in Children's Working Memory: Do Maintenance Mechanisms Matter?

Previous studies using working memory span tasks have shown that phonologically similar words were less recalled than dissimilar words in adults. This phonological similarity effect (PSE) is known to affect their maintenance of verbal information. More precisely, PSE is considering as an indicator of the use of articulatory rehearsal. The small or absent PSE in young children has often been taken as evidence for the view that young children do not rehearse to maintain verbal information. The aim of the present study was to explore phonological effect in 6- to 8-year-old children and to investigate the impact of a concurrent articulation. We also chose to control for attentional refreshing, because this mechanism allows the maintenance of verbal information in working memory. In two complex span tasks, children had to maintain lists of rhyming, similar or dissimilar words. The opportunity for refreshing was manipulated by varying the attentional demand of the concurrent task. Children had perform the concurrent task silently or aloud to impede the articulatory rehearsal. Our results showed that PSE appeared from 6 years of age, and at 8 this effect interacts with the presence of concurrent articulation. However, this effect relied only on the detrimental effect of the phonologically similar words, dissimilar and rhyming words leading to similar recall performance. In addition, PSE did not interact with the manipulation of attentional demand whatever the children's age. These results suggested that children could adapt the strategy used at 8, but articulatory rehearsal is available from at least the age of 6.