Fig 4. Volley coding and stochastic resonance.

A. By varying the stimulus rate, Spikeling can be setup to ‘miss’ individual stimulus cycles at the level of the spike output (left). However, when elicited, spikes remain phase locked to the stimulus (right). B. Example of stochastic resonance. As (A), with neuron hyperpolarised just enough to prevent all spikes (left). Now, addition of membrane noise occasionally elicits spikes (middle), which again are phase locked to the stimulus (right). Dotted line indicates approximate spike threshold.