Differentiation of cortical areas: effects of free energy minimization with broken symmetry

We studied separation and integration of cortical areas during cortical neurogenesis using growth simulations that depend upon matching of spatial frequencies between areas-a method equivalent to maximizing zero-lag pulse synchrony and minimizing prediction errors. In a uniform neural field areas would emerge as mirror pairs with intervening Markov blankets, but regional disparities break this mirror symmetry. Differential effects of disparity of information inputs, cell types, and axonal lengths were characterized in the simulations, explaining how asymmetries of information transfer arise and lead to greater or lesser segregation of systems, sequencing of exchanges, and reciprocal control effects. In the developmentally completed form, nonspecific excitation and frequency modulation from limbic and subcortical sources would modulate exchanges and sequencing, introducing non-hierarchical information flows within the hierarchical radial architecture.