Interaction symmetry: Assessing augmented speaker and oral speaker performances across four tasks.

This investigation examined the impact of speech-generating devices (SGDs) on the interaction dynamics (i.e., symmetry) of augmented speakers and their conversation partners while performing several interaction tasks. This study involved 20 dyads: 10 in which one individual had ALS and primarily used an SGD for communication while the other participant primarily used speech (AS group); and 10 in a control group comprised of individuals who used speech as a primary means of communication (OS group). Interactions between participants in the AS group were compared across four tasks (i.e., map, retell, sequencing, and personal narrative). These results were also compared to performances of participants in the OS group performing the same tasks. Task completion times, talk times, contribution types (i.e., main/repair), and contribution functions (i.e., presentation/acceptance) were used to index symmetry performance patterns across tasks for the 20 dyads. Within- and between-group comparisons were significant in differentiating the two groups in terms of the ways in which they were able to adapt to different interaction task dynamics. Findings suggest symmetry is a useful metric for identifying the constraining influence of carrying out in-person interactions with an SGD.