Synchronous oscillations in the cerebral cortex

The dynamics of a cortex driven by a finite number of white-noise point sources is studied using a recently developed wave-equation formulation. Green's functions, power spectra, fluctuation levels, and two-point correlation functions are computed analytically and numerically. It is shown that a range of observed properties of so-called synchronous oscillations in the cerebral cortex can be correctly reproduced using the wave equation that involves only excitatory interactions between neurons. In particular, the observed existence of a maximal correlation at zero temporal lag between spatially separated points is reproduced and explained for a cortex driven by two white-noise sources.