Visuospatial bootstrapping: implicit binding of verbal working memory to visuospatial representations in children and adults

When participants carry out visually-presented digit serial recall, their performance is better if they are given the opportunity to encode extra visuospatial information at encoding - a phenomenon that has been termed 'visuospatial bootstrapping'. This bootstrapping is the result of integration of information from different modality-specific short term memory systems and visuospatial knowledge in long term memory, and can be understood in the context of recent models of working memory that address multimodal binding (for example models incorporating an 'Episodic Buffer'). Here we report a cross-sectional developmental study that demonstrated visuospatial bootstrapping in adults (n = 18) and 9 year-old children (n = 15), but not in 6 year-old children (n = 18). This is the first developmental study addressing visuospatial bootstrapping and results demonstrate that the developmental trajectory of bootstrapping is different to that of basic verbal and visuospatial working memory. This pattern suggests that bootstrapping (and hence integrative functions such as the Episodic Buffer) emerge independently of the development of basic working memory slave systems during childhood.