Suggestions for Improving the Investigation of Gesture in Aphasia

Looking at gesture: The reciprocal influence between gesture and conversation

INTRODUCTION

There is limited research in group communication treatment for people with aphasia but existing studies report benefits of gesture to support conversation. Gesture supports conversation through recipient design features and reducing linguistic demands of lexical retrieval and formulation. Additionally, gesture serves an affiliative function. However, the relationship between gesture use and gestural capacity has not been widely examined. As part of a larger study on group cohesiveness and conversation, this investigation examined the patterns of co-speech gesture within authentic conversations among persons with aphasia to discern the functions of gesture use for the participants, changes in the use of gesture over time, and the relationship between gesture use and gesture ability.

METHODS

Conversation Analysis (CA) was applied in an embedded case-study design. Three participants received an academic semester of group and individual conversation-based treatment according to Facilitating Authentic Conversation (Damico et al., 2015). Four conversations from the treatment were selected and transcribed for multi-modality communication with CA conventions applied, and then cyclically analysed for patterns of gesture.

RESULTS

Participants demonstrated gesture that served social and linguistic functions: ratifying clinicians' proxy turns, turn-allocation, turn repair, relaying novel visual information, emphasizing content, demonstrating affiliation with the prior speaker, demonstrating their assessment others' talk, and demonstrating humor. All three participants showed an increased rate of gesture per turn and increasingly used gesture to repair conversation breakdown. Increased gesture use over the course of the semester coincided with increased scores for pantomime on the Porch Index of Communicative Ability (Porch, 1981, PICA).

CONCLUSION

Individuals with aphasia demonstrated increased use of gesture for varied purposes and improved gestural processing following a semester of conversation-based treatment. This is significant because gesture is an effective support for the repair of conversation breakdown typical of persons with aphasia.

Evidence of Audience Design in Amnesia: Adaptation in Gesture but Not Speech

Speakers design communication for their audience, providing more information in both speech and gesture when their listener is naïve to the topic. We test whether the hippocampal declarative memory system contributes to multimodal audience design. The hippocampus, while traditionally linked to episodic and relational memory, has also been linked to the ability to imagine the mental states of others and use language flexibly. We examined the speech and gesture use of four patients with hippocampal amnesia when describing how to complete everyday tasks (e.g., how to tie a shoe) to an imagined child listener and an adult listener. Although patients with amnesia did not increase their total number of words and instructional steps for the child listener, they did produce representational gestures at significantly higher rates for the imagined child compared to the adult listener. They also gestured at similar frequencies to neurotypical peers, suggesting that hand gesture can be a meaningful communicative resource, even in the case of severe declarative memory impairment. We discuss the contributions of multiple memory systems to multimodal audience design and the potential of gesture to act as a window into the social cognitive processes of individuals with neurologic disorders.