Figure 4
(a) The excitatory (σexc = 0.2 mm; dark-blue) and inhibitory (σinh = 0.7 mm; light-blue, shown inverted) intra-collicular synaptic connections, and their total effect (black line) for central neuron at neural population generating 15 deg saccade, result in a symmetric local excitatory and global inhibitory connectivity. The net excitation around the neuron (at 0) approaches the value of + 0.23. (b) Total effect of excitatory and inhibitory intra-collicular synaptic connections for neurons across motor map generating different saccade amplitude. The intra-collicular synaptic connections are stronger towards the rostral zone (thus counter-acting the higher firing rates) than towards the caudal zone (where cells have lower firing rates).
