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

Area of Science:

• Neuroscience
• Psycholinguistics
• Cognitive Science

Background:

• Turn-taking is fundamental to spoken dialogue, yet specific neural signatures for anticipating turn-ends remain elusive.
• Existing methods like anticipation timing accuracy (ATA) primarily capture conscious processes, overlooking preconscious anticipation.

Purpose of the Study:

• To investigate the utility of readiness potentials (RP) as a neural marker for preconscious turn-end anticipation.
• To determine the onset of preconscious turn-end anticipation by simultaneously measuring EEG (RP) and behavioral responses (ATA).

Main Methods:

• Utilized a 32-channel EEG system to record brain activity during a simulated spoken dialogue task.
• Participants (n=30) performed motoric (button-press) and articulatory (verbal 'yes') responses upon anticipating turn-ends.
• Simultaneously recorded EEG signals (RP) and behavioral anticipation timing accuracy (ATA) for both response types.

Main Results:

• Readiness potentials (RP) exhibited similar temporal patterns for both button-press and verbal responses.
• RP signals initiated approximately 1170-1190 ms prior to the observed behavioral responses, indicating early preparation.

Conclusions:

• The consistent RP time course across response modalities validates RP as an online marker for response preparation in dialogue.
• This study provides evidence for using RPs to investigate preconscious processes in turn-taking and spoken dialogue research.