The Relationship Between Spatial Transformations and Iconic Gestures

Current theories of gesture production all suggest that spatial working memory is a critical component of iconic gesture production. However, none of the models has a selection mechanism for what aspect of spatial working memory is gestured. We explored how expert and journeyman scientists gestured while discussing their work. Participants were most likely to make iconic gestures about change over time (spatial transformations), less likely to gesture about spatial relations and locations (geometric relations), and far less likely to gesture about the magnitude of spatial entities. We also found that experts were especially likely to have a high degree of association between iconic gestures and spatial transformations. These results show that different features of spatial language are gestured about at different rates. We suggest that current gesture production models need to be expanded to include selection mechanisms to account for these differences.