Encoding with synchrony: phase-delayed inhibition allows for reliable and specific stimulus detection.

Synchronized oscillations are observed in a diverse array of neuronal systems, suggesting that synchrony represents a common mechanism used by the brain to encode and relay information. Coherent population activity can be deciphered by a decoder neuron with a high spike threshold or by a decoder using phase-delayed inhibition. These two mechanisms are fundamentally different - a high spike threshold detects a minimum number of synchronous input spikes (absolute synchrony), while phase-delayed inhibition requires a fixed fraction of incoming spikes to be synchronous (relative synchrony). We show that, in a system with noisy encoders where stimuli are encoded through synchrony, phase-delayed inhibition enables the creation of a decoder that can respond both reliably and specifically to a stimulus, while a high spike threshold does not.