Neurodevelopmental oscillatory basis of speech processing in noise

Area of Science:

• Neuroscience
• Developmental Psychology
• Speech Perception

Background:

• Understanding speech in noise is crucial for human communication.
• This ability develops throughout childhood and adolescence.
• Neural mechanisms underlying speech processing mature with age.

Purpose of the Study:

• To investigate the neuromaturational basis of speech-in-noise comprehension.
• To quantify how brain oscillations track linguistic structures in varying noise conditions.
• To identify age-related changes in neural speech processing.

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity.
• 144 participants aged 5-27 years were studied.
• Cortical oscillations were analyzed while participants listened to connected speech with noise, tracking phrasal and syllabic information.

Main Results:

• Processing prosodic cues in clear speech was stable, but its maintenance in noise matured by age 9, correlating with comprehension.
• Syllable processing matured by age 9, with its robust extraction in noise continuing to develop into adulthood.
• Distinct developmental trajectories were observed for processing different linguistic unit sizes.

Conclusions:

• Neural tracking of speech in noise shows distinct maturational paths for different linguistic grain sizes.
• Larger linguistic units (phrases) mature earlier than smaller units (syllables) in noisy conditions.
• These findings support grain-size proposals in speech perception development, with noise introducing further delays.