Enhanced recognition and recall of new words in 7- and 12-year old children following a period of offline consolidation

Recent studies of adults have found evidence for consolidation effects in the acquisition of novel words (Dumay & Gaskell, 2007), but little is known about whether such effects are found developmentally. In two experiments we familiarized children with novel nonwords (e.g., biscal) and tested their recognition and recall of these items. In Experiment 1 7-year old children were then retested either the same or the following day to examine changes in performance after a short delay compared with a longer delay including sleep. Experiment 2 used two age groups (7and 12-year old children), with all participants retested 24 hours later. Twelve-year-old children accurately recognized the novel nonwords immediately after exposure, as did 7-year-olds in Experiment 2 (but not 1), suggesting generally good initial rates of learning. Experiment 1 revealed improved recognition of the novel nonwords after both short 3-4 hour and longer 24 hour delays. In contrast, recall was initially poor but showed improvements only when children were re-tested 24-hours later, not after a 3-4 hour delay. Similar improvements were observed in both age groups despite better overall performance in 12-year-olds. We argue that children, like adults, exhibit offline consolidation effects on the formation of novel phonological representations.