Competing conceptual representations trigger co-speech representational gestures

Various interconnections between the processing of speech and gesture have been demonstrated in the literature. However, it is not well understood what cognitive factors influence intra-speaker variation of the gesture frequency. This study investigates the hypothesis that provides a unifying explanation for the previous findings on this issue; namely, competing representations in the conceptualisation process for speaking trigger representational gestures. Twenty adult participants described complex geometric figures. In the easy condition, the organisation of the lines necessary for conceptualisation were highlighted by making some lines darker, but in the hard condition, unnecessary competitor conceptualisations were highlighted. The descriptions in the two conditions were lexically comparable. However, the rate of representational gestures (but not that of beat gestures) was higher in the hard condition than in the easy condition. This finding is compatible with the idea that gestures may play a role in the conceptualisation process for speaking.