Subthreshold signal + noise → enhanced detection (leaky integrate-and-fire)
Stochastic resonance (SR) is a phenomenon where an optimal amount of noise enhances detection of a subthreshold signal. The leaky integrate-and-fire (LIF) neuron: τ dV/dt = −V + I(t) + σξ(t), fires when V > V_th = 1. Without noise, the subthreshold signal (A < V_th) never triggers spikes. Too much noise drowns the signal. The optimal noise level maximizes signal-to-noise ratio (SNR), creating a peak in the SNR vs σ curve — the hallmark of stochastic resonance.