Head gesture timing is constrained by prosodic structure

Abstract

There is an increasing consensus to regard gesture and speech as parts of an integrated communication system, in part because of the findings related to their temporal coordination at different levels. In general, results for different types of gestures show that the most prominent part of the gesture (the apex) is typically aligned with accented syllables [6, 10-12, 14, 17]. The aim of the present study is to test for this coordination by focusing on head movements taken from a semi-spontaneous setting in order to look at the effects of upcoming phrase boundaries on their timing. Our results show that while apexes of head gestures are synchronized with accented syllables, upcoming phrase boundaries have an effect on the timing of three gestural points, namely the start, apex, and end time of head gestures. Crucially, these points are aligned differently with respect to the stressed syllable for trochees as compared with iambs/monosyllables, showing that head nods are retracted before upcoming phrase boundaries. This result corroborates previous results by Esteve-Gibert & Prieto [17] for pointing gestures in laboratory settings.