Using a Phenomenological Mathematical Model to Reproduce the Interaction of Endogenous and Exogenous Oscillations under Neurocontrol

Abstract

The aim of the study was to evaluate the possibility of using a phenomenological mathematical model of the thalamocortical unit cell to describe the frequency-time responses of the real thalamocortical system (namely, various alpha rhythm modulations) and reproduce the signal dynamics in the process of neurobiocontrol. Materials and Methods. The experimental part of this study (the resonant neurobiocontrol with double feedback based on the BioFeedBack2 software-hardware complex) was carried out according to the hybrid protocol: background-before/after: 2-minute record of the baseline vertex EEG (the active electrode-Cz grounding and the reference electrodes held on the earlobes); frequency scan during 210 s: exposure to pulsed infrared radiation with an increasing rate of from 8 to 14 Hz (frequency step-0.1 Hz, time step-3 s) and a music-like sound signal, the tone and volume of which determined by the peak amplitude in the spectrum of the current EEG in the range of 8-14 Hz. The characteristic feedback time is 10 ms, the frequency accuracy is 0.2-0.4 Hz. Periodic noise pulses, presented with a frequency related to the baseline heart rate, have been added to the sound signal. For the calculations, a previously developed phenomenological model of the thalamocortical unit cell was used. The model incorporates interacting modules simulating the major neuronal modules of the brain, i.e., the thalamus, the cortex and the thalamic reticular nuclei. Results and Discussion. Using the proposed phenomenological mathematical model of the thalamocortical unit cell, we obtained frequency-time responses of the model signal, which reproduces the frequency pattern of the real EEG signal. The model simulates the situation when the baseline alpha rhythm changes in response to an external factor with the known thalamocortical parameters. In the future, this information will improve the current feedback procedures of biocontrol aimed at enhancing the cognitive power of the brain. Appropriate training will allow controlling the alpha rhythm frequency (neurobiolcontrol) in such a way that, by the objective psychophysical criteria, the subjects will have their cognitive activity enhanced, and, by the subjective assessment, their well-being will improve. Conclusion. In this study, a neuro-informational approach to personalized brain rhythm management is demonstrated. It is now possible to reproduce individual features of a complex information processing system using the proposed phenomenological model of the thalamocortical unit cell.

Resonance Scanning as an Efficiency Enhancer for EEG-Guided Adaptive Neurostimulation

“…Resonance scanning makes it possible to observe the dynamics of resonant EEG responses at the stimulation frequency (rhythm entrainment) and at the frequency of harmonics (rhythm multiplication). From the literature, it is known that these EEG responses reflect the degree of functional lability, adaptive potential, and non-linearity of brain reactions due to the mechanisms of interaction between endogenous and exogenous oscillations [ 13 ], neural entrainment [ 14 , 15 ], and controlled neuroplasticity [ 16 , 17 ]. Based on these mechanisms, resonance scanning increases the brain’s responsiveness to subsequent adaptive neurostimulation, acting as a kind of pre-tuning of the brain, which cause the activation of potential resonators in the EEG spectrum.…”