Experimental neurophysiology

In studying the brain activities it is important to know how the brain structures are functionally interconnected and how information is spread. Intracerebral EEG signals are the unique source data for the evaluation of brain activity. A typical dataset contains many channels (up to 200) covering different areas in the brain. It is, therefore, possible to explore not only each channel separately, but also dependencies between channels to obtain additional information.
The aim of experimental brain functioning stimulation is to obtain relevant information on the functional properties of brain areas. In the case of high-frequency records, there are differences in data size, frequency bands and processing requirements. Evoked potentials measured on the scalp are commonly analyzed up to 50 Hz. High-frequency deep brain records allow analysis of signals at frequencies of up to 2000 Hz. This high sampling frequency, simultaneously combined with improved data quality, enable entirely new research into evoked brain behavior.
Several methods for the detection of connections and interaction between brain structures are used - correlation function and coherency, the multichannel model, partial directed coherence (PDC), directed transfer function (DTF), and methods based on autoregressive spectral estimation of multivariate signals, etc.

Deep brain activity research – induced mental activity, structural conectivity.
The MediSig has long focused on intracerebral EEG recording and analysis, including paradigm design and high-quality data acquisition, artefact detection and data scoring, statistical evolution and presentation of the results in graphic form. Additionally, we have also provided a completely new methodology for multidimensional cross-correlation analysis of spatial couplings and two-dimensional interpretation of brain interactions.