(color online) Spatiotemporal patterns of ring coupled neuronal network for different values of noise intensity for fixed external forcing current , feedback gain coefficient k=0.5, autaptic conductance g=0.1, delay time τ =10.0 ms, field coupling intensity g₀ =1.0, noise intensity (a) D=0.0, (b) D=0.1, (c) D=0.2, and (d) D=1.0. Autapses are activated at t = 120 ms for only four nodes 19–22 and electromagnetic disturbances are triggered at t = 500 ms for all nodes.