Using the readiness potential of button-press and verbal response within spoken language processing

Abstract

h i g h l i g h t s• Detection of readiness potential onset represents a preconscious measure for end-of-turn anticipation in a language dialogue.• Even if it is a language task it can be applied equally well to both verbal and finger movement responses.• In contrast to behavioural reaction time tasks the EEG-measurement produces more reliable data for the anticipation performance in end-of-turndetection.a r t i c l e i n f o New method: The purpose of this study was to examine if readiness potentials (RP) can be used to study the anticipation of turn-ends by using it in a motoric finger movement and articulatory movement task. The goal was to determine the preconscious onset of turn-end anticipation in early, preconscious turn-end anticipation processes by the simultaneous registration of EEG measures (RP) and behavioural measures (anticipation timing accuracy, ATA). For our behavioural measures, we used both button-press and verbal response ("yes"). In the experiment, 30 subjects were asked to listen to auditorily presented utterances and press a button or utter a brief verbal response when they expected the end of the turn. During the task, a 32-channel-EEG signal was recorded. Results: The results showed that the RPs during verbal-and button-press-responses developed similarly and had an almost identical time course: the RP signals started to develop 1170 vs. 1190 ms before the behavioural responses. Comparison with existing methods: Until now, turn-end anticipation is usually studied using behavioural methods, for instance by measuring the anticipation timing accuracy, which is a measurement that reflects conscious behavioural processes and is insensitive to preconscious anticipation processes. Conclusion: The similar time course of the recorded RP signals for both verbal-and button-press responses provide evidence for the validity of using RPs as an online marker for response preparation in turn-taking and spoken dialogue research.

The Brain Behind the Response: Insights Into Turn-taking in Conversation From Neuroimaging

“…A similar conclusion was drawn from two recent EEG studies (Jansen, Wesselmeier, De Ruiter, & Mueller, 2014;Wesselmeier, Jansen, & Müller, 2014) using a known ERP component, the Readiness Potential (RP) or Bereitschaftspotential (Kornhuber & Deecke, 1965), a slow negative-going cortical potential associated with the preparation of voluntary movements. Participants heard materials recorded by an instructed speaker, rather than being extracted from conversational corpus materials as used in the studies cited in the previous paragraph.…”

“…Participants heard materials recorded by an instructed speaker, rather than being extracted from conversational corpus materials as used in the studies cited in the previous paragraph. The first study (Jansen et al, 2014) used both a button-press and a spoken-response paradigm, in which participants were asked to give a short verbal answer (yes or no). In both tasks, an RP was found to start almost 1,200 milliseconds before the response.…”

Turn-taking: From perception to speech preparation

“…In exploring the two results of this study in combination with previous research on the RP development turn-taking [7], response preparation of formulated sentences delays the RP-onset compared to the simple verbal cue "Ja" (yes) as a response. However, both short and long RTs caused the same RP-onset to response interval, indicating different time intervals for the response decision, but the same intervals for response preparation (lexical selection, lemma and phonological retrieval).…”

“…during anticipation [7] have shown that the response-locked RP of vocal onset is similar to RP of a button-press. This evidence means that a voice-related RP-onset can be used for motor preparation in the same manner as it is used for button-press and is not affected by breathing in or other preparation factors for verbalization.…”

Is Language Special? Anticipation Timing Accuracy of End of Turns in Known and Unknown Languages

“…In an electroencephalographic (EEG) study with German sentence stimuli, participants were instructed to press a button exactly at the moment an aurally presented sentence ended. A lateralized readiness potential related to the button press was observed 600 to 800 milliseconds before the end of the sentences, indicating that participants were aware of the sentence end 600 to 800ms before it actually ended [22]. Although only based on aural clues, this early anticipation leaves plenty of time for the listener to prepare their own turn and allows the turn transition to be smooth.…”