Figure 7. Large random networks spontaneously compute.

(A) Each site in a 10×10 grid is either empty or occupied by an excitatory (green) or inhibitory (red) neurons (probabilistically). (B) Connectivity matrix. (C) Example run. (D) Entropy and divergence as a function of time for random initial conditions. (E) The number of different subspaces visited reduces as a function of time similarly to the entropy. (F) Time ±s.d. till the network first enters a permitted subspace as a function of network size, specified as grid with. 100 runs of randomly assembled networks were simulated for each size. The larger the network, the longer the network spent going through the forbidden subspaces. Panels A–E show an example of grid size 10. See Methods for simulation details.