Decoding gestural iconicity

Representational gestures are used ubiquitously to depict ideas in an iconic fashion, such as when holding up the thumb and the index finger at a certain distance to indicate the size of a matchstick. However, the process by which a physical hand configuration is mentally transformed into abstract spatial information is not well understood. We present a series of experiments that investigate how people decode the physical form of an articulator to derive imaginary geometrical constructs, which are embraced in our use of “gesture form”. We provide quantitative evidence for several key properties that play a role in this process. First, “profiling”, the ability to focus on a structural sub-unit within the complex form of the gesturing hand. Second, “perspective”, for which we show that one and the same handshape seen from different perspectives can lead to different spatial interpretations. Third, “selectivity”, the fact that gestures focus on certain spatial features at the expense of others. Our results provide a first step toward mapping out the process of how representational gestures make the communication of spatial information possible.