Obligatory Processing Of Irrelevant Gesture

This paper presents a study of selected iconic gestures with a view to determining their effects on RT in a task-relevant and a task-irrelevant context. In two experiments, participants were presented with a coloured shape on a computer screen, a spoken statement referring to the presented shape, and a gesture that was task irrelevant. The findings from both experiments show strong support for the assumption that gesture processing is obligatory; irrelevant gestures affected speed of task performance. Furthermore the findings suggest that for slower, more cognitively controlled decisions incongruent gestures have an inhibitory effect, while for faster, more cognitively automated decisions congruent gestures have a facilitatory effect.