This study investigated the role of joint attention in infants' word learning. Infants aged 18–21 months were taught new words in two social contexts, joint attention (eye contact, positive tone of voice) or non-joint attention (no eye contact, neutral tone of voice). Event-related potentials were measured as the infants saw objects either congruent or incongruent with the taught words. For both social contexts, an early negativity was observed for the congruent condition, reflecting a phonological-lexical priming effect between objects and the taught words. In addition, for the joint attention, the incongruent condition elicited a late, widely distributed negativity, attributed to semantic integration difficulties. Thus, social cues have an impact on how words are learned and represented in a child's mental lexicon.
aMax Planck Institute for Human Cognitive and Brain Sciences
bSchool of Linguistics and Language Studies and Institute of Cognitive Science, Carleton University, Canada
cHunter College, The City University of New York, New York, USA
Correspondence to Dr Masako Hirotani, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1a, Leipzig 04103, Germany
Tel: +49 341 9940 107; fax: +49 341 9940 260; e-mail: firstname.lastname@example.org
Received 28 January 2009 accepted 2 February 2009