Polarization-wave propagation as a biophysical mechanism of visual cognition

Abstract

Recent experimental studies indicate that visual cognition is accompanied by slowly propagating biophysical travelling waves in cortical tissue. Here we propose polarization waves as a coherent physical framework for visual cognition. We first compute the propagation of scalar potential fields generated by impressed ionic currents in the primary visual cortex using a telegraph-type model and extract the velocity of the moving potential ridge. By exploiting the linear convolution structure, we then demonstrate that the scalar potential field and the polarization wave, arising from slowly oscillating neuronal dipoles, propagate with identical velocities. Remarkably, this velocity coincides with the independently predicted propagation speed of the cognitively inferred modulated wave (~1.5 cm/s). Because ionic influx entering a single optic-nerve channel integrates signals from more than a hundred photoreceptors, the resulting polarization field necessarily spans a distribution of wave numbers. We show that amplitudes of such multi-k polarization waves undergo dispersive spreading in time, which possibly suppresses cross-channel interference in visual perception.