Left hemispheric α band cerebral oscillatory changes correlate with verbal memory

Area of Science:

• Neuroscience
• Cognitive Science
• Biomarkers

Background:

• Event-related synchronisation (ERS) and desynchronisation (ERD) are observed in the language-dominant hemisphere using magnetoencephalography (MEG).
• The precise relationship between ERS/ERD and clinical language indices remains unclear, necessitating further investigation.

Purpose of the Study:

• To investigate the relationship between brain activity (ERS/ERD) during a verb generation task and clinical language indices.
• To determine ERS/ERD power values across various frequency bands (θ, α, β, low γ, high γ).
• To identify potential neurophysiological biomarkers for verbal memory.

Main Methods:

• Utilized magnetoencephalography (MEG) to evaluate brain activity in 36 subjects during a verb generation task.
• Measured event-related synchronisation (ERS) and event-related desynchronisation (ERD) power values in θ, α, β, low γ, and high γ frequency bands.
• Assessed clinical language indices using the Wechsler Memory Scale-revised.

Main Results:

• Observed alpha-band ERD in bilateral occipital to left central regions, beta-band ERD in bilateral occipital to left frontal regions, and low gamma-band activity in the left frontal region.
• Detected theta-band ERS in bilateral frontal regions and high gamma-band ERS in bilateral occipital regions.
• Found a significant negative correlation between alpha-band ERD power in the left postcentral gyrus/medial superior frontal gyrus and verbal memory scores (r = -0.574, -0.597).

Conclusions:

• Individuals with lower linguistic memory exhibit less desynchronized alpha-band ERD power.
• Alpha-band ERD power in the left hemisphere may function as a neurophysiological biomarker for verbal memory.
• MEG-based ERS/ERD analysis provides insights into the neural correlates of verbal memory.