The dissertation consists of three parts. In the first part, Levelt's 'Blueprint of the Speaker' speech production model is extended to incorporate the production of gesture. The second part is a detailed experimental study of the temporal synchronization of pointing gestures and concurrent speech. De Ruiter shows that pointing gestures are closely synchronized with speech, even in the case of speech hesitations and interruptions. The third part addresses the issue of the potential facilitatory function gesture has on speech production.
Evidence is found that gesturing aids the retrieval of visual imagery during speech production.
This study compared the formal features of the spontaneous gestures and signs produced in the narration of an animated cartoon. The Gesture Phone coding system was developed to phonetically transcribe the data. The first set of findings showed that two-handed gestures and signs in the narratives violate the 'Symmetry Condition' to the same degree. The Symmetry Condition states that when two hands move without touching each other, the movement and configurational features of the sign must be the same or symmetrical for the two hands. Two-handed signs in which each hand produces separate morphemes violated the Symmetry Condition especially frequently.