Joint entropy loci of M and P cells: a hypothesis for parallel processing in the primate visual system.

The M and P neurons connect the retinal inner plexiform layer to the magnicellular and parvicellular layers of the lateral geniculate nucleus and to layer 4 of the primary visual cortex. The M and P pathways transmit visual signals with different six-dimensional joint entropy for space, spatial frequency, time and temporal frequency. Beyond V1 layer 4, M and P influences mix in information processing streams which connect different visual cortical areas. Some visual cortical cells perform better than it is possible for linear filters, regarding to simultaneous spatial and spatial frequency localization of their response. This can be explained by nonlinear combination of M and P input on such cells.