Input correlations impede suppression of chaos and learning in balanced firing-rate networks
Fig 7
Common input impedes learning in balanced networks.
A) Schematic of the training setup. A ‘student network’ (S) is trained to autonomously generate the output , by matching its recurrent inputs to those of a driven ‘teacher network’, whose weights are not changed during training. B) λ1 in the teacher network as a function of I1. C) Test error in the student network as a function of I1. Critical input amplitude
is indicated by vertical dashed lines. Consistent with the difference in
, the teacher networks driven with common input require a larger I1 to achieve small test errors in the student network. Error bars indicate interquartile range around the median. D) Top: Target output
(green) and actual output z (dashed orange) for two input amplitudes I1 ∈ {5, 15}. Bottom: Firing rate ϕ(hi) for two example neurons in teacher network with common input (green full line) and student network (orange dotted line) for two input amplitudes. E) Scatter plot of test error as a function of λ1 for each network realization in A and B, with both common and independent input. When chaos in the teacher network is not suppressed (λ1 > 0), test error is high. Training is successful (small test error) when targets are strong enough to suppress chaos in the teacher network. Training is terminated when error reaches below 10−2. Model parameters: N = 500, g = 2, I0 = J0 = 1, ϕ(x) = max(x, 0) in both teacher and student networks; f = 0.2/τ in the teacher network inputs and target
.