Figure 28
From: Coverage, continuity, and visual cortical architecture
The EN model with deterministic annealing and fourth derivative stencil. (a) OPMs (left) and RMs (right) for N = 103 (upper row), N = 104 (middle row) and N = 105 (lower row) stimuli, non-periodic boundary conditions, and annealing rate χ = 0.999. β is the continuity parameter in the conventional definition of the EN model (see 'Methods' section, Equation (46)) and is scaled, such that a comparable number of columns is emerging in the simulations for each stimulus set. (b) Pinwheel densities (upper left) of EN solutions, SD of pinwheel densities estimated from randomly selected regions in the solutions (upper right). Crosses mark individual simulations, red line indicates average values. Black dashed curve indicates SD for a two-dimensional Poisson process of equal density. Statistics of nearest neighbor pinwheel distances for pinwheels of arbitrary (lower left) and (lower right) opposite and equal charge for 105 random stimuli and periodic boundary conditions, averaged over four simulations (red curves). Black curves represent fits to the experimental data from [38]. (c) As a but for nonperiodic boundary conditions. (d) As b, but for non-periodic boundary conditions. (e) OPMs (left) and RMs (right) for N = 20 × 20 × 8 (upper row), N = 50 × 50 × 8 (middle row) and N = 100 × 100 × 8 (lower row) stimuli, nonperiodic boundary conditions, annealing rates χ = 0.999. (f) As b, but for nonperiodic boundary conditions and grid-like stimuli.