< Back to Article

Neuronal mechanisms for sequential activation of memory items: Dynamics and reliability

Fig 9

Phase portraits corresponding to critical transitions in Scenario 1 and Scenario 2.

These phase portraits occur for a special value of σ such that changes from a saddle to a sink. (a) The phase portrait of the critical transition corresponding to Scenario 1 contains a sequence of connecting trajectories from ξ¹ to ξ², allowing for a transition from ξ¹ to ξ² with arbitrarily small noise (e.g. for ρ = 2.4, τ_r = 900, λ = 0.55, μ = 0.45, the critical transition occurs at s₁ ≈ 0.45, s₂ ≈ 0.56). (b) In the phase portrait of the critical transition corresponding to Scenario 2, a transition from ξ¹ to ξ² would fail unless the noise amplitude is sufficiently large. (e.g. for ρ = 2.4, τ_r = 900, λ = 0.55, μ = 0.15, the critical transition occurs at s₁ ≈ 0.37, s₂ ≈ 0.49).

doi: https://doi.org/10.1371/journal.pone.0231165.g009