Spatiotemporal phase clusters and phase synchronization patterns derived from high density EEG and ECoG recordings

- Spatial resolution in EEG and ECoG data collection systems.
- Higher phase cluster in epileptogenic areas.
- Higher phase synchronization index (SI) in epileptogenic areas.
- Techniques to compute phase cluster patterns.
- Techniques to compute phase synchronization index (SI).

High density scalp EEG and subdural ECoG recordings provide an opportunity to map the electrical activity of the cortex with high spatial resolution. The spatial power spectral densities conform to a power law distribution with some nonlinear variations. The spatiotemporal patterns of phase derived from these data sets have unique features, such as, amplitude and phase modulation waves and also exhibited formation of spatial phase cluster patterns. These unique features represent different cognitive states and are different between normal and diseased states. Reported results show that the rate of formation of phase cluster patterns derived from the seizure-free interictal EEG data are higher in epileptogenic zones as compared with nearby normal areas of the brain.