Information processing

The analysis consists of the following steps:


1. Eye movement artifact correction and elimination

a) using spatial filtration technique based on zeroing the activation curves of individual Independent Component Analysis (ICA) components corresponding to horizontal and vertical eye movements, as well as b) excluding  epochs with excessive amplitude of EEG and excessive faster and slower frequency activity;

2. Fast-Fourier Transformation (FFT)

… of the corrected EEG for extracting EEG power and coherence for all narrow bins in the frequency band from 0.5 to 30 Hz.

3. Computation of event related potentials

… by averaging EEG over trials for each category of trial and each channel with high time resolution.


4. Decomposition of an individual ERPs

… into independent components by applying spatial filters extracted by means of the ICA from the collection of ERPs computed for the corresponding group of healthy subjects.

5. Comparison of each extracted electrophysiological and behavioral variable

… against the corresponding variable computed for a carefully constructed and statistically controlled age-regressed, normative database in which the variables have been transformed and confirmed for their Gaussian distribution.

The comparison is made using parametric statistical procedures that express the differences between the patients and their appropriate age-matched reference group in the form of Z-scores. The results of analysis and statistical comparison are compiled into an individual report.