Mathematical model of phase coding of events in the brain

Slow alpha- and theta-resemblance waves generated by coordinated neuronal activity under activity of nonspecific subcortical inputs create conditions for the dynamic change of excitability of neuronal local groups which, in turn, generate high-frequency gamma oscillation because of external inputs' influence. Arrival of these signals in the most vulnerable phase of the slow rhythm creates a good situation for local gamma rhythms generation. On the basis of these positions, an original model of rhythms’ interaction in neuronal networks of the brain was developed and investigated. In computational modeling experiments, management of amplitude and phase of theta waves is shown, that can serve as an effective way of transformation of the psychophysical scale of event perception (patterns of input signals) into micro-time scales of neuronal messages. One of key elements of a new paradigm is a fundamental role of interaction of rhythms in coding, compression and coordination of neuronal messages in brain. The developed model of a neuronal network represents a network of weak linked nonlinear oscillators and every one of them can generate high-frequency packs modulated by a slow oscillation rhythm. In the model, nonlinear interactions of these rhythms allow to obtain an exact understanding of how the spatial organization of neurons and its inputs at the cells level explains such phenomena of fast and slow oscillatory activity of brain interaction as time compression of the coded messages, masking and of some other.