Frequency decomposition and phase synchronization of the visual evoked potential using the empirical mode...

Area of Science:

• Neuroscience
• Signal Processing
• Cognitive Science

Background:

• Electroencephalogram (EEG) phase characteristics offer insights into human sensory perception.
• Visual evoked potential (VEP) is a key EEG component reflecting visual processing.
• Understanding VEP's frequency composition is crucial for brain function analysis.

Purpose of the Study:

• To investigate the phase characteristics of frequency components within EEG signals.
• To determine if VEP can be decomposed into phase-synchronized frequency bands.
• To analyze the relationship between VEP components and visual brain function.

Main Methods:

• Decomposition of EEG signals into frequency components using empirical mode decomposition (EMD).
• Application of Hilbert transform (HT) for signal extraction and synthesis into frequency bands.
• Analysis of VEP components (δ, θ, α, β) using amplitude, latency, and phase-locking value (PLV).

Main Results:

• VEP was successfully decomposed into phase-synchronized δ, θ, α, and β frequency signals.
• Phase-locking value (PLV) was significantly higher in posterior brain regions compared to anterior regions.
• Elevated theta band PLV was observed in the occipital region during visual stimulation.

Conclusions:

• Decomposing VEP signals into phase-synchronized frequency components provides a novel analysis method.
• This approach facilitates the study of brain activation patterns related to visual stimuli.
• Phase analysis of VEP components offers a valuable tool for understanding visual perception mechanisms.