Changes in multimodal communication synchrony (Murillo et al., 2018)

<div><b>Purpose: </b>The aim of this study is to analyze the changes in temporal synchrony between gesture and speech of multimodal communicative behaviors in the transition from babbling to two-word productions.</div><div><b>Method: </b>Ten Spanish-speaking children were observed at 9, 12, 15, and 18 months of age in a semistructured play situation. We longitudinally analyzed the synchrony between gestures and vocal productions and between their prominent parts. We also explored the relationship between gestural– vocal synchrony and independent measures of language development.</div><div><b>Results: </b>Results showed that multimodal communicative behaviors tend to be shorter with age, with an increasing overlap of its constituting elements. The same pattern is found when considering the synchrony between the prominent parts. The proportion of overlap between gestural and vocal elements at 15 months of age as well as the proportion of the stroke overlapped with vocalization appear to be related to lexical development 3 months later.</div><div><b>Conclusions: </b>These results suggest that children produce gestures and vocalizations as coordinated elements of a single communication system before the transition to the two-word stage. This coordination is related to subsequent lexical development in this period.</div><div><br></div><div>Examples of Types of Gestures Coded in the Study</div><div><br></div><div><b>Supplemental Material S1.</b> Examples of pointing gestures.</div><div><br></div><div><b>Supplemental Material S2. </b>Example of reaching gesture.</div><div><br></div><div><b>Supplemental Material S3. </b>Example of showing gesture.</div><div><b><br></b></div><div><b>Supplemental Material S4.</b> Example of give gesture.</div><div><br></div><div><b>Supplemental Material S5.</b> Example of conventional gesture.</div><div><br></div><div><b>Supplemental Material S6.</b> Example of symbolic gesture.</div><div><br></div><div><b>Supplemental Material S7. </b>Example of “other” gesture.</div><div><br></div><div><b>Supplemental Material S8. </b>Sequence of the preparation phase of the gesture. The arm starts to move until its full extension.</div><div><br></div><div><b>Supplemental Material S9. </b>Sequence of the stroke phase of the gesture. The expression of the gesture is fully accomplished, indicating where the attention of the observer is intended to go.</div><div><br></div><div>Examples of the Phases of Gestures Coded in the Study</div><div><br></div><div><b>Supplemental Material S10.</b> Sequence of the retraction phase of the gesture. The arm moves from the stroke position until the initial rest position.</div><div><br></div><div>Murillo, E., Ortega, C., Otones, A., Rujas, I., & Casla, M. (2018). Changes in the synchrony of multimodal communication in early language development.<i> Journal of Speech, Language, and Hearing Research</i>. Advance online publication.</div><div><br></div><div><br></div>