High connection sparsity increases the robustness of networks to inactivation. a, Psychometric function for a network with a recurrent connection probability of 0.4 after training (gray) and after a 20% (medium-size) inactivation (dark blue). b, Chronometric function before and after inactivation for the same network. c, Fraction of correct responses as a function of the functional integrity index, α, estimated for each network. d, Changes of sensitivity (slope of psychometric function) caused by a 20% inactivation across five trained networks for different sparsity levels. e, Effects of inactivation on bias across the trained networks. f, Changes of mean decision times across networks. Error bars show s.e.m. over five networks for lesions and all 20 networks for intact. Maximal trial duration set to 500 steps.