Neural correlates of regional EEG power change

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• Understanding the physiological basis of electroencephalogram (EEG) rhythms during cognitive tasks is crucial.
• Task-related changes in brain activity are often reflected in both electrical (EEG) and hemodynamic (rCBF) signals.

Purpose of the Study:

• To investigate the relationship between regional cerebral blood flow (rCBF) and EEG power during various tasks.
• To clarify the physiological significance of task-related EEG rhythm alterations.

Main Methods:

• Simultaneous recording of EEG and H2 15O positron emission tomography (PET) scans in eight subjects.
• EEG data acquired from occipital and bilateral sensorimotor areas during rest and self-paced movement tasks.
• Quantitative correlation analysis between EEG power and rCBF.

Main Results:

• Significant negative correlations found between sensorimotor EEG rhythm (10-20 Hz) and ipsilateral sensorimotor rCBF.
• Negative correlation observed between occipital EEG rhythm (10-20 Hz) and occipital rCBF.
• Positive correlations noted between occipital EEG rhythm and bilateral medial prefrontal rCBF, and right sensorimotor EEG rhythm and left prefrontal rCBF.

Conclusions:

• A decrease in the 10-20 Hz EEG rhythm in specific regions may signify underlying cortical neuronal activation.
• The prefrontal cortex appears to play a role in the generation of EEG rhythms through neural networks.