1
|
Theta Band (4-8 Hz) Oscillations Reflect Online Processing of Rhythm in Speech Production. Brain Sci 2022; 12:brainsci12121593. [PMID: 36552053 PMCID: PMC9775388 DOI: 10.3390/brainsci12121593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/24/2022] Open
Abstract
How speech prosody is processed in the brain during language production remains an unsolved issue. The present work used the phrase-recall paradigm to analyze brain oscillation underpinning rhythmic processing in speech production. Participants were told to recall target speeches aloud consisting of verb-noun pairings with a common (e.g., [2+2], the numbers in brackets represent the number of syllables) or uncommon (e.g., [1+3]) rhythmic pattern. Target speeches were preceded by rhythmic musical patterns, either congruent or incongruent, created by using pure tones at various temporal intervals. Electroencephalogram signals were recorded throughout the experiment. Behavioral results in 2+2 target speeches showed a rhythmic priming effect when comparing congruent and incongruent conditions. Cerebral-acoustic coherence analysis showed that neural activities synchronized with the rhythmic patterns of primes. Furthermore, target phrases that had congruent rhythmic patterns with a prime rhythm were associated with increased theta-band (4-8 Hz) activity in the time window of 400-800 ms in both the 2+2 and 1+3 target conditions. These findings suggest that rhythmic patterns can be processed online. Neural activities synchronize with the rhythmic input and speakers create an abstract rhythmic pattern before and during articulation in speech production.
Collapse
|
2
|
Corcoran AW, Perera R, Koroma M, Kouider S, Hohwy J, Andrillon T. Expectations boost the reconstruction of auditory features from electrophysiological responses to noisy speech. Cereb Cortex 2022; 33:691-708. [PMID: 35253871 PMCID: PMC9890472 DOI: 10.1093/cercor/bhac094] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 02/04/2023] Open
Abstract
Online speech processing imposes significant computational demands on the listening brain, the underlying mechanisms of which remain poorly understood. Here, we exploit the perceptual "pop-out" phenomenon (i.e. the dramatic improvement of speech intelligibility after receiving information about speech content) to investigate the neurophysiological effects of prior expectations on degraded speech comprehension. We recorded electroencephalography (EEG) and pupillometry from 21 adults while they rated the clarity of noise-vocoded and sine-wave synthesized sentences. Pop-out was reliably elicited following visual presentation of the corresponding written sentence, but not following incongruent or neutral text. Pop-out was associated with improved reconstruction of the acoustic stimulus envelope from low-frequency EEG activity, implying that improvements in perceptual clarity were mediated via top-down signals that enhanced the quality of cortical speech representations. Spectral analysis further revealed that pop-out was accompanied by a reduction in theta-band power, consistent with predictive coding accounts of acoustic filling-in and incremental sentence processing. Moreover, delta-band power, alpha-band power, and pupil diameter were all increased following the provision of any written sentence information, irrespective of content. Together, these findings reveal distinctive profiles of neurophysiological activity that differentiate the content-specific processes associated with degraded speech comprehension from the context-specific processes invoked under adverse listening conditions.
Collapse
Affiliation(s)
- Andrew W Corcoran
- Corresponding author: Room E672, 20 Chancellors Walk, Clayton, VIC 3800, Australia.
| | - Ricardo Perera
- Cognition & Philosophy Laboratory, School of Philosophical, Historical, and International Studies, Monash University, Melbourne, VIC 3800 Australia
| | - Matthieu Koroma
- Brain and Consciousness Group (ENS, EHESS, CNRS), Département d’Études Cognitives, École Normale Supérieure-PSL Research University, Paris 75005, France
| | - Sid Kouider
- Brain and Consciousness Group (ENS, EHESS, CNRS), Département d’Études Cognitives, École Normale Supérieure-PSL Research University, Paris 75005, France
| | - Jakob Hohwy
- Cognition & Philosophy Laboratory, School of Philosophical, Historical, and International Studies, Monash University, Melbourne, VIC 3800 Australia,Monash Centre for Consciousness & Contemplative Studies, Monash University, Melbourne, VIC 3800 Australia
| | - Thomas Andrillon
- Monash Centre for Consciousness & Contemplative Studies, Monash University, Melbourne, VIC 3800 Australia,Paris Brain Institute, Sorbonne Université, Inserm-CNRS, Paris 75013, France
| |
Collapse
|