A signal has to be predictable enough to be recognizable as a signal,but have enough variation ,or randomness to convey something.Bateson( I studied w/ him too) along with Warren McColough, Norbert Wiener and others cofounded the discipline of Cybernetics.His definition of information: A difference that makes a difference. My interpretation: Nerves register difference . Animals on this planet tend to have sensory systems attuned to the bandwidths of what they eat and what eat's them.In the Wild, when something moves in ones sensory field ,attention goes there.If it is predator ,or prey that constitutes a difference that makes a difference, attention stays there approprite response s ensue. Ifit was just the wind blowing the leaves,it doesn't make any difference,and attention returns to random ,or stochastic scanning. Of course we humans have transcended the primitive state and our attention gets filled with various of the abstractions that we generate.