Demographic, neuropsychological, and speech variables that impact iconic and supplementary-to-speech gesturing in aphasia

Abstract

We model the role of demographic, neuropsychological and speech variables in characterizing iconic gesture use in speakers with aphasia, especially gestures that supplement speech and are essential for understanding the spoken message. Using backward regression modelling with cross validation in 37 speakers with aphasia, literature-derived demographic (e.g., age), neuropsychological (e.g., aphasia and anomia severity), and speech (e.g., speaking duration) variables were used to predict frequency and rate (per minute) of iconic, supplementary, and essential gesturing. We identified that nearly 60% of iconic gestures produced by speakers were supplementary to speech with 38% being essential for understanding the speech. Generally, those with more severe aphasia, anomia, and with nonfluent aphasia tended to produce fewer tokens and a slower rate of speech, and these were the speakers who produced more and a higher rate of supplementary and essential gestures. These findings underline the importance of iconic gestures to improve communication.