Enhanced brainstem and cortical encoding of sound during synchronized movement

Area of Science:

• Auditory Neuroscience
• Sensorimotor Integration
• Human Electrophysiology

Background:

• Movement synchronization is a key model for understanding motor-sensory alignment.
• The impact of synchronized movement on sensory pathway encoding remains largely unexplored.

Purpose of the Study:

• To investigate how auditory sensory encoding is modulated during synchronized rhythmic movement.
• To examine concurrent brainstem and cortical electroencephalographic (EEG) activity during auditory-motor synchronization.

Main Methods:

• Simultaneous electroencephalographic (EEG) recording from the brainstem and cortex.
• Participants listened to amplitude-modulated tones under passive listening and synchronized tapping conditions.
• Utilized frequency-tagging to isolate brainstem and cortical responses to auditory stimuli and their modulations.

Main Results:

• Cortical responses at the beat frequency were amplified during synchronized tapping compared to passive listening.
• Brainstem responses showed enhanced amplification of sidebands, particularly for lower-pitched tones, during movement.
• Auditory processing gains were selective to behavior-relevant sound features and not directly correlated with tapping electromyography.

Conclusions:

• Sensorimotor synchronization dynamically enhances auditory encoding in both subcortical and cortical pathways.
• The frequency-tagging method is effective for studying concurrent auditory-motor processes during movement.
• Findings reveal online gain control in auditory processing shaped by active movement and sound relevance.