The lateral connection strength to an excitatory neuron (a) and that to an inhibitory neurons (b) as function of distance in each layer. In this graph, the parameter values of various synaptic strengths and various connection rediuses are: gee = 0.25 mS, gie = 0.5 mS, gei = 0.3 mS, gii = 0.3 mS, Ree = 0.5 mm, Rie = 0.5 mm, Rei = 1.0 mm, Rii = 1.0 mm