Iverson and Thelen (1999) highlight the significance of bodily experience in human cognition. They emphasise the importance of the body and how it moves through space, interacting with the world, and affecting how we then process information.
Research within the field of speech and movement focus on three potential theories which may explain the presence of nonverbal gestures during communication. The first is a very linear theory, which essentially purports that the production of speech initiates the production of gestures. The second theory is similar, but in addition to this causal relationship between speech and gestures, this theory claims that gestures can be used to trigger speech if the person is having difficulty recalling a word from memory. Lastly the most embodied theory suggests that speech and gestures are fully interdependent. This would suggest that if one aspect of communication was disrupted the other aspect would be affected too. For example if the ability to move one’s body in order to produce gestures was inhibited, one’s ability to process information would be hindered. This is a potentially controversial statement, suggesting that people who are less mobile, for example due to paralysis or amputation, do not process information as well as they might if they had full range of movement.
One piece of evidence supporting this embodied theory of speech and gesture is research conducted by Hanlon (1990) who studied patients with severe left hemisphere damage and aphasia (reduced ability to name known stimuli). Participants were shown images of known objects and asked to gesture towards the object as they attempted to name it. They were instructed to either point at the object with their finger, or make a fist in the direction of the object. Hanlon found that finger pointing increased the accuracy with which participants were able to name the objects, compared with making a fist, suggesting that more specific and accurate gestures can improve cognition (or at least verbal production).