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

• Infants start combining gesture with speech from the early one-word stage.
• Early gesture-speech combinations contain mostly deictic gestures with declarative intention.
• Infants’ coordination of gesture and speech starts already at the babbling stage.
• Infants’ multimodal coordination is adult-like when prominence is taken into account.

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.