Figure 4.

Dependence of the quality of the map on parameters. Axonal (filled symbols) and synaptic (open symbols) delay-tuning indices (averaged over N = 30 neurons) have been plotted for ipsilateral (red squares) and contralateral (green triangles) NM afferents. Insets (signatures as in Fig. 3F) show the map at different stages. (A) Delay-tuning indices are a function of learning time t. The interaction parameter is ρ = 0.3/N; all other parameters and initial conditions are the same as in Fig. 3. Because alignment is not perfect, synaptic delay-tuning indices exceed the axonal ones. (B) Delay-tuning indices of the final map are a function of the interaction parameter ρ. The same random seed for all simulations gives a smooth dependence on ρ. Restricting the interaction to 8 neighboring neurons (ρ = 0.7/16) (C), filtered white-noise input (D), or a distribution of axonal conduction velocities 4 ± 0.5 m/s (E) hardly changes the final map.