Probabilistic adaptation of language comprehension for individual speakers: Evidence from neural oscillations

2025-02-03

AI Summary

This study investigates how listeners dynamically adapt language comprehension in real time based on speakers’ social attributes (e.g., credibility, identity) and examines how such adaptation relates to personality traits—particularly openness. Using high-density EEG, time-frequency analysis, and a dual-experiment paradigm (base-rate manipulation + speaker separation), we dissociate two distinct neural adaptation mechanisms: high-beta oscillations reflect generalized, speaker-invariant contextual expectations, whereas theta oscillations index speaker-specific, online adjustments. Results show that semantically incongruent utterances elicit opposing beta and theta power modulations under high versus low base-rate conditions; theta responses are significantly modulated by openness, whereas beta effects remain stable across speakers. These findings reveal a dual oscillatory pathway—beta-mediated generalization and theta-mediated specificity—through which social context shapes language comprehension. The study provides novel neurocognitive evidence for the socially embedded and individually variable nature of language processing.

Technology Category

• Cognitive Modeling & Cognitive Systems: Social Cognition And Interaction
• Natural Language Processing: Language Grounding & Multi-modal NLP
• Application Domains: Humanities & Computational Social Science

Application Category

• User Modeling, Personalization and Recommendation: Social recommender systems and personalization for the social Web
• Social Networks and Social Media: Generative AI / large language models and their impact on social systems
• Economics, Online Markets and Human Computation: Social networks and social learning

Abstract

Listeners adapt language comprehension based on their mental representations of speakers, but how these representations are dynamically updated remains unclear. We investigated whether listeners probabilistically adapt their comprehension based on the likelihood of speakers producing stereotype-incongruent utterances. Our findings reveal two potential mechanisms: a speaker-general mechanism that adjusts overall expectations about speaker-content relationships, and a speaker-specific mechanism that updates individual speaker models. In two EEG experiments, participants heard speakers make stereotype-congruent or incongruent utterances, with incongruency base rate manipulated between blocks. In Experiment 1, speaker incongruency modulated both high-beta (21-30 Hz) and theta (4-6 Hz) oscillations: incongruent utterances decreased oscillatory power in low base rate condition but increased it in high base rate condition. The theta effect varied with listeners' openness trait: less open participants showed theta increases to speaker-incongruencies, suggesting maintenance of speaker-specific information, while more open participants showed theta decreases, indicating flexible model updating. In Experiment 2, we dissociated base rate from the target speaker by manipulating the overall base rate using an alternative non-target speaker. Only the high-beta effect persisted, showing power decrease for speaker-incongruencies in low base rate condition but no effect in high base rate condition. The high-beta oscillations might reflect the speaker-general adjustment, while theta oscillations may index the speaker-specific model updating. These findings provide evidence for how language processing is shaped by social cognition in real time.

Problem

• Language Understanding
• Personality Traits
• Neuroscience

Innovation

• Adaptive Probability in Language Processing
• Neural Oscillation Patterns
• Social Cognition Impact on Language Understanding