Speech Perception and Preparation Are Supported by Distinct Neural Dynamics Across Development.

Speech development requires precise timing and sensorimotor integration, supported by neural oscillations that synchronize activity across auditory, motor, and cognitive circuits. Among speech-relevant frequency bands, beta oscillations (13-30 Hz) are critical for timing and coordination, supporting sensorimotor processing and speech preparation. Beta desynchronization (power decreases) is typically observed prior to movement, reflecting motor planning, and beta activity also supports cognitive functions such as attention and anticipation. Although age-related changes in beta power have been documented, its developmental trajectory during speech processing remains underexplored. Here, we compared beta power dynamics in 28 adults (mean age = 27.8 yr) and 50 children (mean age = 10.3 yr) during speech perception and production tasks using EEG. On each trial, participants received a visual cue indicating the condition ("Say," "Hear," or "See"), followed by rhythmic tones and a warning cue presented as a picture with its name (e.g., cat) in Say and Hear, but only as a picture in See. A Go cue then prompted participants to speak, listen, or maintain fixation. Beta power was analyzed in three time windows: postwarning cue (P1), pre-Go cue (P2), and post-Go cue (P3). Adults exhibited significant beta power decreases across all time windows, particularly in Say, indicating mature sensorimotor and cognitive integration. In contrast, children showed no significant condition effects and minimal beta reduction in P3. Beta modulation was negatively correlated with age in children, suggesting ongoing maturation of beta oscillations. These findings highlight key developmental differences in beta oscillations relevant to speech processing.