Henderson, L. 1 , Weighall, A. 2 & Gaskell, G. 1
1 University of York
2 Sheffield Hallam University
Although the acquisition of a novel spoken form is often rapid, previous research on adults suggests that integration of novel and existing knowledge (measured by engagement in lexical competition) requires a consolidation period associated with sleep. These findings are well-explained by neural models of learning in which sleep provides an opportunity for hippocampal information to be fed into long-term neocortical memory. It remains unclear whether this time-course dissociation characterises word learning in children. Fifty-three children (7 - 12 years) were exposed to novel competitor words at 07:30-09:30 (AM Group) or 17:30-19:30 (PM Group). Whilst children were able to recognise and recall some novel words immediately after exposure, performance improved significantly after sleep (at the 12-hr retest for the PM Group and the 24-hr retest for the AM Group) and remained good 8 days later. Similarly, novel words only induced competition effects after a period of sleep (rather than wake). These findings suggest that children utilize a dual-memory system in the acquisition and integration of vocabulary. Since previous research into vocabulary acquisition in children has largely focused on the immediate consequences of word learning, the present data call for a shift in our conception of vocabulary acquisition in development.