Figure 9.

Impact of place-field width and strength of inhibitory feedback loop on replay events. The number of ripples (A, C) and the matching index (B, D) versus the number of g₀ of initially synchronous neurons after a fixed number of runs (averaged over n = 10,000 replay events) are shown. In A and B, different colors indicate different place-field widths Δw, and in C and D, different colors correspond to different scaling γ of the inhibitory feedback loop (compare Eq. 28) as indicated above the panels. Increasing Δw yields a faster learning of feedforward structure, and thus a faster increase of the ordering of replay events. The inhibitory feedback controls the number of ripples per replay event: with decreasing γ, more and more ripples (i.e., longer events) emerge. However, the longer replay events do not lead to more ordered sequences as the synchronous signal tends to spread out over larger parts of the recurrent network. For more detailed discussion, see the main text.