  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.
