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

Author-Highlights
• High threshold or phase-delayed inhibition can both decode synchronized oscillations.
• High threshold and phase-delayed inhibition detect absolute vs. relative synchrony.
• No noise: high threshold decoder and phase-delayed inhibition perform equally well.
• With noise: phase-delayed inhibition performs better than a high threshold.

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.