Next speakers plan word forms in overlap with the incoming turn: evidence from gaze-contingent switch task performance

Mathias Barthel,Stephen C Levinson

doi:10.1080/23273798.2020.1716030

Abstract

ABSTRACT To ensure short gaps between turns in conversation, next speakers regularly start planning their utterance in overlap with the incoming turn. Three experiments investigate which stages of utterance planning are executed in overlap. E1 establishes effects of associative and phonological relatedness of pictures and words in a switch-task from picture naming to lexical decision. E2 focuses on effects of phonological relatedness and investigates potential shifts in the time-course of production planning during background speech. E3 required participants to verbally answer questions as a base task. In critical trials, however, participants switched to visual lexical decision just after they began planning their answer. The task-switch was time-locked to participants' gaze for response planning. Results show that word form encoding is done as early as possible and not postponed until the end of the incoming turn. Hence, planning a response during the incoming turn is executed at least until word form activation.

Highlights

In conversation, interlocutors readily exchange turns of talk, frequently switching from the role of the listener to the role of the speaker without leaving long gaps between turns (Sacks, Schegloff, & Jefferson, 1974; Stivers et al, 2009)
Experiment 1 examined the effects of associative relatedness and phonological relatedness of pictures and words on lexical decision performance in a switch task
Decisions were faster if words were presented after pictures that were associated with the words than after pictures that were unrelated to the words, and decisions were slower and yielded more errors if words were presented after a picture whose name was phonologically related to the word as compared to when they were presented after an unrelated picture, with this effect of phonological inhibition being most pronounced at an stimulus-onset asynchronies (SOAs) of 200 ms

Summary

Introduction

Interlocutors readily exchange turns of talk, frequently switching from the role of the listener to the role of the speaker without leaving long gaps between turns (Sacks, Schegloff, & Jefferson, 1974; Stivers et al, 2009). While participants dealt with the respective tasks (picture naming as base task; lexical decision as switch task in 25% of trials), they were auditorily presented with one question per trial in order to test whether the same effects of phonological inhibition can be observed at the same SOA as in Experiment 1 if participants are presented with distracting speech input while attending to the switch task. Following Experiment 2, in which questions were presented as distracting background speech that had to be ignored by participants, Experiment 3 makes use of a dialogic task in order to investigate whether speakers plan their utterance phonologically in overlap with the incoming turn. The relatedness of the lexical decision words and the target picture was manipulated in order to investigate whether participants already retrieved the word form of the picture name in overlap with the incoming question or not. If the word form of the picture name was already retrieved by the time of the task switch, activation of the lexical decision word should be inhibited, leading to longer decision latencies and increased error rates

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Conclusion