title: Eye-tracking the time-course of novel word learning and lexical competition in adults and children.
abstract: Lexical competition is a hallmark of proficient, automatic word recognition. Previous research suggests that there is a delay before a new spoken word becomes engaged in this process, with sleep playing an important role. However, data from one method - the visual world paradigm - consistently show competition without a delay. We trained 42 adults and 40 children (aged 7-8) on novel word-object pairings, and employed this paradigm to measure the time-course of lexical competition. Fixations to novel objects upon hearing existing words (e.g., looks to the novel object biscal upon hearing "click on the biscuit") were compared to fixations on untrained objects. Novel word-object pairings learned immediately before testing and those learned the previous day exhibited significant competition effects, with stronger competition for the previous day pairings for children but not adults. Crucially, this competition effect was significantly smaller for novel than existing competitors (e.g., looks to candy upon hearing "click on the candle"), suggesting that novel items may not compete for recognition like fully-fledged lexical items, even after 24h. Explicit memory (cued recall) was superior for words learned the day before testing, particularly for children; this effect (but not the lexical competition effects) correlated with sleep-spindle density. Together, the results suggest that different aspects of new word learning follow different time courses: visual world competition effects can emerge swiftly, but are qualitatively different from those observed with established words, and are less reliant upon sleep. Furthermore, the findings fit with the view that word learning earlier in development is boosted by sleep to a greater degree.
authors: School of Psychology, University of Leeds, Leeds LS2 9JT, UK. Electronic address: a.r.weighall@leeds.ac.uk.
authors: A R
authors: AR
authors: Weighall
authors: Department of Psychology, University of York, York YO10 5DD, UK. Electronic address: lisa-marie.henderson@york.ac.uk.
authors: L M
authors: LM
authors: Henderson
authors: Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK. Electronic address: dale.barr@glasgow.ac.uk.
authors: D J
authors: DJ
authors: Barr
authors: Department of Psychology, University of York, York YO10 5DD, UK. Electronic address: scott.cairney@york.ac.uk.
authors: S A
authors: SA
authors: Cairney
authors: Department of Psychology, University of York, York YO10 5DD, UK. Electronic address: gareth.gaskell@york.ac.uk.
authors: M G
authors: MG
authors: Gaskell
mesh_terms: D000328:Adult; D002648:Child; D003463:Cues; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006309:Hearing; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D012660:Semantics; D012890:Sleep / Q000502:physiology*; D014936:Word Association Tests; D055815:Young Adult
keywords: Acquisition; Complementary learning systems (CLS); Language development; Learning; Memory consolidation; Sleep; Spoken word recognition; Visual world paradigm; Word learning