Schedule of Events | Symposia

Beta Bursting During Naturalistic Speech Processing

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom
Also presenting in Data Blitz Session 1 - Saturday, March 29, 2025, 10:30 am – 12:00 pm EDT, Grand Ballroom.

Lindsey Power¹ (lindsey.power@mail.mcgill.ca), Sylvain Baillet¹; ¹McGill University

Cortical oscillations in the beta (15-30 Hz) frequency range are increasingly studied for their role in top-down control of neural circuit functions. Beta oscillations manifest as brief bursts with distinct timing and frequency properties. However, associations between these properties and cognitive processes beyond the motor domain remain to be resolved. The present work investigates the hypothesized involvement of beta bursting in predictive processes participating in naturalistic speech processing. MEG data was obtained from 11 healthy participants listening to TED talk recordings. We trained an artificial neural network to predict upcoming speech tokens, and outputs were used to derive proxy measures of the contextual uncertainty and lexical surprisal surrounding each phoneme and word in the audio recordings. We mapped the cortical sources of MEG data and detected ongoing beta bursts in 200 regions of interest. We found that beta bursting was strongly modulated by contextual and lexical speech features. Specifically, beta bursting decreased during speech segments with high uncertainty and surprise. This effect mapped bilaterally over the auditory cortex and broadly over left frontal and temporal regions typically associated with language. Moreover, duration, magnitude, and peak frequency of the beta bursts correlated with contextual metrics over a subset of these language-related regions. Together, these findings suggest broad involvement of beta bursting in predictive speech processes across the language network. Further research on the functional relevance of burst characteristics in relation to speech variables will provide more insight into the nature of naturalistic speech processing by the human brain.

Topic Area: LANGUAGE: Lexicon