The Effect of Visual vs. Verbal Stimuli on Gesture Production

Previous research suggests that speakers gesture more when they are describing information learned in a visuo-spatial format than when describing information learned in a verbal format. The present study examined whether this difference in gesture is due to decreased verbal accessibility when information has been learned visuo-spatially or to the decreased accessibility of mental images when information has been learned verbally. Participants described the events of stories learned in two conditions. In one condition, the participants heard a verbal description twice. In the other condition, the participants heard the verbal description once and then watched an animated cartoon of the events. We found increased representational gestures when speakers had watched the cartoon in addition to hearing its description. Importantly, this increase in gesture does not appear to be due to differences in speech accessibility or output, suggesting that speakers gesture when they have a clear image in mind and not just when they do not have ready access to verbal labels.