A Mathematical Model of Hippocampal Spatial Encoding. II. Neurodynamic Correlates of Mental Trajectories and Decision-Making Problem

The work is a continuation of studies related to the construction of conceptual neurodynamic model of formation of environment spatial representations and purposeful behavior in the mammals brain, the first part of which has been published earlier. The effective vector–phase way of neuron network representations of spatial trajectories episodes is proposed in development of this model. The results of the modeling of medial entorinal cortex "grid cells" and hippocampal "place cells" functional interaction in the generation of straight lines and the reverse temporary sequences of events (replays) are described. The phenomenon of disparity of "mental" representations of episodes in ipsi- and contralateral reference systems is obtained for the first time due to the bilateral organization of networks with even cyclic inhibition (ECI-networks). Neurodynamical correlates of numerous predictive (look-ahead) generation of trajectories with various starting and final positions in contralateral system and unique trajectories — in ipsilateral system on the basis of which a choice (decision-making) of movement route can be made are presented. The universal nature hypothesis of egocentric representations formation in ipsilateral reference system and allocentric in contralateral system of each hemisphere of a brain is offered in the paper. On the basis of the obtained results the problem of future research for decision-making mechanisms depending on a goal and an existential context in a behavior episode is formulated.