Cortico-cortical associations and EEG coherence: a two-compartmental model

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Brain Connectivity

Background:

• Electroencephalogram (EEG) coherence measures the synchronization of brain activity between different scalp locations.
• Understanding age-related changes in EEG coherence is crucial for mapping developing neural networks.
• Previous research has explored EEG coherence, but spatial asymmetries and their underlying mechanisms require further investigation.

Purpose of the Study:

• To investigate spatial inhomogeneities in EEG coherence in children aged 5-16 years.
• To differentiate the contributions of short and long-range axonal connections to EEG coherence.
• To develop and validate a 'two-compartmental' model of EEG coherence.

Main Methods:

• Computed EEG coherence from 19 scalp locations in 189 children (ages 5-16).
• Assessed spatial homogeneity by comparing anterior-to-posterior and posterior-to-anterior interelectrode distances.
• Analyzed phase delays as a function of interelectrode distance to support a compartmental model.

Main Results:

• Significant inhomogeneities in EEG coherence were observed.
• Greater coherence was found in the anterior-to-posterior direction compared to posterior-to-anterior.
• Increased coherence was noted in frontal derivations versus posterior derivations and in the right hemisphere versus the left hemisphere.

Conclusions:

• EEG coherence is influenced by at least two distinct sources: short- and long-range axonal connections.
• A 'two-compartmental' model explains how different fiber systems contribute to EEG coherence.
• The findings provide a basis for hypotheses on hemispheric and regional differences in brain connectivity during development.