Comparing the cognitive load of gesture and action production: a dual-task study

Speech-accompanying gestures have been shown to reduce cognitive load on a secondary task compared to speaking without gestures. In the current study, we investigate whether this benefit of speech-accompanying gestures is shared by speech-accompanying actions (i.e., movements that leave a lasting trace in the physical world). In two experiments, participants attempted to retain verbal and spatial information from a grid while describing a pattern while gesturing, while making the pattern, or while keeping hands still. Producing gestures reduced verbal load compared to keeping hands still when the pattern being described was visually present (Experiment 1), and this benefit was not shared by making the pattern. However, when the pattern being described was not visually present (Experiment 2), making the pattern benefited verbal load compared to keeping hands still. Neither experiment revealed a significant difference between gesture and action. Taken together, the findings suggest that moving the hands in meaningful ways can benefit verbal load.