Functional Roles of Sensorimotor Alpha and Beta Oscillations in Overt Speech Production.

Area of Science:

• Neuroscience
• Speech Motor Control
• Brain Oscillations

Background:

• Sensorimotor alpha and beta oscillations, specifically event-related desynchronization (ERD), are recognized indicators of sensorimotor control during overt speech.
• The precise functional roles of these oscillations in speech production remain incompletely understood.

Purpose of the Study:

• To systematically review the modulation of alpha and beta ERD in speech motor tasks for typically fluent speakers (TFS) and persons who stutter (PWS).
• To investigate the potential functional dissociation between alpha and beta ERD in speech production.

Main Methods:

• A systematic review of eleven EEG/MEG studies incorporating source localization was conducted.
• Analysis of existing intracranial electroencephalography (iEEG) data from the primary somatosensory cortex (S1) during picture naming tasks.

Main Results:

• Consistent alpha and beta ERD were observed in the sensorimotor cortex of both TFS and PWS.
• Findings suggest alpha ERD is associated with (somato-)sensory feedback processing during articulation.
• Beta ERD appears linked to motor processes during speech planning and articulation.
• Analysis of iEEG data provided moderate evidence for alpha ERD sensitivity to speech movements in S1, supporting functional dissociation.

Conclusions:

• Sensorimotor alpha and beta ERD exhibit distinct functional roles in speech production.
• Alpha ERD is implicated in sensory feedback processing, while beta ERD is involved in motor control during speech.
• These findings contribute to a deeper understanding of neural mechanisms underlying fluent and disfluent speech.