DC-EEG recordings of mindfulness

Area of Science:

• Neuroscience
• Electroencephalography (EEG)

Background:

• The human electroencephalogram (EEG) typically focuses on faster frequency bands.
• Ultra-slow brain waves, below the infraslow band, have been less explored in standard EEG analysis.

Purpose of the Study:

• To investigate the frequency spectrum of the normal waking human eyes-closed EEG during a mental task.
• To identify and characterize ultra-slow brain wave activity, including near-DC components.

Main Methods:

• Ten healthy adult volunteers underwent 128-channel DC-based EEG recording.
• Mindfulness meditation was used as the mental task for approximately 65 minutes.
• Data analysis included topographic display, frequency analysis, and independent component analysis using BESA Research software.

Main Results:

• All subjects exhibited near-DC activity lasting over an hour.
• Rhythmic wave durations between 10 and 35 minutes were observed.
• The primary topographic distribution of this activity was in the frontal midline areas and inferior hemispheres.

Conclusions:

• The study confirms the existence of rhythms below the infraslow band and a near-DC component in the normal human EEG.
• The clinical significance of these ultra-slow waves in health and disease requires further investigation.
• Researchers with DC-based EEG/MEG systems are encouraged to analyze their data for these ultra-slow waves.