P06Session 2 (Friday 13 January 2023, 09:00-11:00)Timing of head turns to upcoming talkers in triadic conversation
In conversation, people are able to listen to an utterance and respond within only a few hundred milliseconds. It takes substantially longer to prepare even a simple utterance, suggesting that interlocutors may make use of predictions about when the talker is about to end. Listeners that are simply following the conversation could also benefit from predicting the turn end in order to shift attention appropriately with the turn switch. We examined whether people predict upcoming turn ends when watching conversational turns switch between others in the group by analysing head movements in natural conversations. These conversations were between triads of older adults in different levels and types of noise. The analysis focused on the observer during turn switches between the other two parties using head orientation (i.e., saccades from one talker to the next) to identify when their focus moved from one talker to the next. For non-overlapping turn switches, head movements were tightly clustered around the onset of the new speaker, but observers sometimes started to turn to the upcoming talker even before the prior talker had finished speaking. These anticipatory movements occurred in 17% of turn switches (going up to 26% when accounting for 200 ms of motor planning time). For overlapping utterances, observers started to turn toward the interrupter before they interrupted in 18% of turn switches (going up to 33% when accounting for motor planning time). Timing of head turns was largely unaffected by noise type and level. These findings demonstrate that listeners try to catch the start of new contributions to a conversation and in doing so often exhibit head movements that anticipate the end of one conversational turn and the beginning of another.