Pointing the way forward: the role of gesture in preschoolers' and adults' communication and comprehension of route direction information

Speakers and listeners use gesture as an integral part of the thinking and communication process. Research has shown that producing gestures enhances spatial task performance for young preschool-aged children and adults, although the relationship between gesture and speech content needs clarification.It is not yet clear whether gesture that repeats speech content is useful, or only gesture that is unique.Further, while it is known that producing gestures accompanying speech enhances memory and speech production for speakers, it is not yet known whether gestures benefit listeners' comprehension and subsequent recall of spatial information. Finally, it is not known whether particular types of gestures accompanying spatial messages are more beneficial to listeners' recall than others. The aim of this thesis was to clarify the role of gesture on spatial route communication and recall across development. Across four studies, this thesis investigated(1) the information relationship between the gestures and speech phrases produced by three-to five-year old children and adults when conveying spatial route information; (2) whether gestures accompanying route directions enhance listeners'recall during development; and (3) whether gestures accompanying route directions enhance adult listeners'recall. Findings were threefold. First, there were important developmental differences in the production of gestures accompanying route direction information, suggesting spatial conceptualisation changes as language and cognition develop. Second, gestures accompanying spoken route directions enhanced both verbal recall and physical route navigation during early childhood. Finally, gestures accompanying spoken route directions enhanced verbal recall for adult listeners when the spoken message was incomplete. However, the benefit of gestures accompanying route directions for adult listeners may depend on the method of recall, with poorer physical route navigation by listeners presented with gestures accompanying route information. Thus, this thesis showed that gestures are an integral part of the spatial communication environment vi for both speakers and listeners, facilitating spatial information delivery and recall,and ultimately influencing spatial information application.