Parkinson's disease affects the neural alpha oscillations associated with speech-in-noise processing

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Movement Disorders

Background:

• Parkinson's disease (PD) is linked to auditory processing deficits.
• Previous behavioral studies show preserved speech-in-noise recognition in PD.
• Neurophysiological underpinnings of speech-in-noise processing in PD remain unclear.

Purpose of the Study:

• Investigate neural oscillatory mechanisms of speech-in-noise processing in PD.
• Compare electroencephalography (EEG) data between PD patients and healthy controls (HCs).
• Correlate neural activity with behavioral performance in auditory tasks.

Main Methods:

• Recruited 12 individuals with PD (medication off) and 12 age/gender-matched HCs.
• Conducted audiometric screening and a sentence-in-noise recognition task.
• Utilized simultaneous electroencephalography (EEG) for neural activity recording and time-frequency analysis.

Main Results:

• No significant differences in delta-theta inter-trial phase coherence between PD and HCs.
• Significantly increased alpha power observed in PD patients during the speech-in-noise task.
• PD group showed decreased behavioral speech recognition scores, but similar effort, performance, and motivation ratings.

Conclusions:

• Individuals with PD may allocate more cognitive resources to compensate for auditory processing challenges.
• Increased alpha power suggests a top-down compensatory mechanism for auditory input degradation in PD.
• Findings highlight the importance of neurophysiological measures beyond behavioral tests for understanding auditory dysfunction in PD.