Alpha-frequency stimulation strengthens coupling between temporal fluctuations in alpha oscillation power and default...

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Imaging

Background:

• Alpha oscillations (8-12 Hz) and default mode network (DMN) activity are key to intrinsic brain function.
• Both alpha oscillations and DMN are implicated in neuropsychiatric disorders.
• Existing research suggests a link between alpha activity and DMN function.

Purpose of the Study:

• To investigate the mechanistic relationship between alpha oscillations and DMN connectivity.
• To examine the effects of alpha-frequency transcranial alternating current stimulation (α-tACS) on this relationship.
• To determine if α-tACS can modulate DMN connectivity.

Main Methods:

• Simultaneous electroencephalogram/functional magnetic resonance imaging (EEG-fMRI) data acquisition.
• Application of α-tACS before and after stimulation.
• Analysis of dynamic coupling between alpha power fluctuations and DMN connectivity.

Main Results:

• α-tACS significantly tightened the dynamic coupling between alpha power and DMN connectivity, particularly in the posterior DMN.
• No significant changes were observed for other oscillatory frequencies or brain networks.
• These findings indicate an inherent coupling between alpha oscillations and DMN activity.

Conclusions:

• Alpha oscillations and DMN activity are inherently coupled in the human brain.
• α-tACS is an effective non-invasive method for regulating DMN connectivity.
• This approach holds potential for therapeutic interventions in neuropsychiatric disorders targeting the DMN.