Measurement of synchronization properties in systems with different excitation levels

We devised a measure based on the distributions of relative event timings of two coupled units. The measure dynamically evaluates temporal interdependencies between the two coupled units. Using this we show that even in the event of symmetrical coupling, non-identical units (having different control parameters) have small but persistent shifts in their event timings that change dramatically with the relative properties of their internal trajectories. We link that finding with the activity dependent synaptic modification in the brain showing that internally or externally driven excitation levels of the neuron may determine direction of information processing in a network.