Context Matters: Hyperscanning the N400 Lexical Frequency Effect during Scripted Conversation and Passive Listening

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Social Neuroscience

Background:

• Language processing research often uses isolated words or sentences.
• Real-world language comprehension frequently occurs in social interactions.
• The N400 event-related potential (ERP) reflects semantic processing, with lower frequency words eliciting a larger N400.

Purpose of the Study:

• To investigate the N400 frequency effect during active conversation versus passive viewing.
• To assess the feasibility of using electroencephalography (EEG) hyperscanning in conversational settings.
• To compare lexical processing in interactive social contexts with traditional experimental paradigms.

Main Methods:

• EEG hyperscanning was employed on pairs of acquaintances conversing or passively viewing a recorded conversation.
• Target words of varying lexical frequencies were identified within synchronized audio and EEG data.
• The N400 component was analyzed to compare frequency effects between the conversational and passive viewing conditions.

Main Results:

• Both groups showed a larger N400 for low-frequency words compared to high-frequency words, confirming the N400 frequency effect.
• The N400 frequency effect was significantly attenuated in the scripted conversation group relative to the passive viewing group.
• This attenuation was most prominent over midline central-parietal scalp regions.

Conclusions:

• Active social interaction during conversation may modulate lexical processing, potentially by facilitating access to word representations.
• The findings suggest that conversational rapport might reduce the cognitive effort associated with processing low-frequency words.
• This study demonstrates the viability of ERP research in naturalistic conversational settings, opening avenues for studying social language processing.