Partial event coincidence analysis for distinguishing direct and indirect coupling in functional network construction

Area of Science:

• Neuroscience
• Complex Systems Analysis
• Time Series Analysis

Background:

• Functional network construction relies on accurate interaction pattern identification from multivariate time series.
• Bivariate association measures often yield false links due to indirect interactions mediated by common drivers.
• Distinguishing direct from indirect links is crucial for reliable network analysis.

Purpose of the Study:

• To generalize event coincidence analysis to a partial version for distinguishing direct and indirect interactions in event-like data.
• To apply the partial event coincidence analysis to electroencephalography (EEG) data for investigating brain connectivity.
• To understand differences in coordinated alpha band activity between eyes open (EO) and eyes closed (EC) resting states.

Main Methods:

• Developed a partial event coincidence analysis to exclude transitive effects of indirect couplings.
• Validated the methodology using coupled chaotic systems and stochastic processes on star and chain topologies.
• Applied the partial event coincidence analysis to multi-channel EEG recordings.

Main Results:

• The proposed methodology correctly identifies indirect interactions in simulated systems.
• Direct connections in EEG data typically link spatially close brain regions, while indirect connections often span longer distances.
• The eyes closed (EC) state shows enhanced frontal brain connectivity compared to the eyes open (EO) state, with reduced posterior connectivity.
• A significant reduction in identified indirect connections was observed.

Conclusions:

• Partial event coincidence analysis effectively distinguishes direct and indirect interactions, improving functional network construction.
• The findings provide insights into brain region coordination during different resting states (EO vs. EC).
• The method aids in understanding the alpha band desynchronization phenomenon observed in the EO state.