Infants temporally coordinate gesture-speech combinations before they produce their first words

This study explores the patterns of gesture and speech combinations from the babbling period to the one-word stage and the temporal alignment between the two modalities. The communicative acts of four Catalan children at 0;11, 1;1, 1;3, 1;5, and 1;7 were gesturally and acoustically analyzed. Results from the analysis of a total of 4,507 communicative acts extracted from approximately 24 h of at-home recordings showed that (1) from the early single-word period onwards gesture starts being produced mainly in combination with speech rather than as a gesture-only act; (2) in these early gesture-speech combinations most of the gestures are deictic gestures (pointing and reaching gestures) with a declarative communicative purpose; and (3) there is evidence of temporal coordination between gesture and speech already at the babbling stage because gestures start before the vocalizations associated with them, the stroke onset coincides with the onset of the prominent syllable in speech, and the gesture apex is produced before the end of the accented syllable. These results suggest that during the transition between the babbling stage and single-word period infants start combining deictic gestures and speech and, when combined, the two modalities are temporally coordinated.A preliminary version of this paper was presented at the conferences Architectures and Mechanisms for Language Processing (Paris, France, September 1-3, 2011) and Gesture and Speech in Interaction (Bielefeld, Germany, September 5-7, 2011). We would like to thank participants at those meetings, especially Marc Swerts, Heather Rusiewicz, and Stefan Kopp, for their helpful comments. We thank Aurora Bel, Louise McNally, and José Ignacio Hualde for being part of the PhD project defense of the first author of the study and for their helpful observations. We also thank Ulf Liszkowski for his useful comments on the analysis of the intentions behind pointing gestures, Simone Bijvoet and Joan Borràs for their help with the statistical analysis, and Alfonso Igualada and Santiago González-Fuente for the inter-rater reliability tests. Finally, we are really grateful to the children and the children’s parents for voluntarily taking part in this study. This research has been funded by two research grants awarded by the Spanish Ministry of Science and Innovation (FFI2009-07648/FILO “The role of tonal scaling and tonal alignment in distinguishing intonational categories in Catalan and Spanish”, and FFI2012-31995 “Gestures, prosody and linguistic structure”), by a grant awarded by the Generalitat de Catalunya (2009SGR-701) to the Grup d’Estudis de Prosòdia, by the Generalitat de Catalunya (2009SGR-701) to the Grup d’Estudis de Prosòdia, by the grant RECERCAIXA 2012 for the project “Els precursors del llenguatge. Una guia TIC per a pares i educadors” awarded by Obra Social ‘La Caixa’, and by the Consolider-Ingenio 2010 (CSD2007-00012) grant