Characterizing iconic gesture during narratives in chronic traumatic brain injury recovery.

Introduction: It is known that co-speech hand gestures increase and supplement speech in individuals with language impairment after brain injury, e.g., post-stroke aphasia. Traumatic Brain Injury (TBI) provides a unique avenue to evaluate gestures as TBI often presents with both anomia (word-finding impairments) and cognitive impairments, resulting in a cognitive-communicative disorder. However, there is a great need for evaluation of gestures in TBI during typical spontaneous speech and across the recovery trajectory (from sub-acute to chronic stages). In a large population ( Methods: In a subpopulation (Group 1, Results: The large group analysis suggested that individuals with TBI use iconic gesture during narrative, which take several different iconic forms (e.g., enacting use of an object), and that a minority employed gestures that supplemented (added to, disambiguated, or replaced) speech. The subpopulation analyses suggested that participants did not produce iconic gestures significantly differently across the 2-year recovery timeframe. Case examination of a participant with moderate-severe aphasia suggested a relationship between language impairment and gesture, with this individual producing the highest proportion of supplemental gesturing of the entire group. This finding aligns with research from the post-stroke aphasia field. Discussion: Broadly, this study significantly extends prior research on the relationship between gesturing, language, and brain injury.