While sitting in the audience of an orchestra concert, I am amazed that the different instruments and sections manage to begin their parts at just at the right time, with perfect volume, and pitch compared to their musical companions. But if I analyzed the symphony in a nitty-gritty matter, their intricate communications would be revealed and their secrets known.
You see, an orchestra cannot function without a director or without particular cues that function as hints to tell the other players when to come in and maybe even when to stop. I even remember from my high school band days that if we needed to play a certain sequence in repetition then the number of times was memorized and the musicians would follow through this way. Such cues are not alone found in music but can be used in plays so that players know what to say when a certain line is stated by a certain actor. This is how corollary discharges can be used as well ..
Because corollary discharges are integral parts of behavior (neurons need to communicate with each other in order to produce behavior) we can further understand behaviors by detecting corollary discharges. It is necessary for the nervous system to have very detailed communications not only externally (via sensory neurons) but internally as well so that cooperation can occur between systems. Corollary discharges are at least partially responsible for the knowledge we have about where our limbs are placed (even without seeing with our eyes) and for other such coordinations such as walking exhibited in crayfish. We cannot find one possible source for these feats so this organization is clearly a function of ganglion communicating between each other (corollary discharges) and not a dictation from some "upper level system".
Corollary discharges make great sense of behavior because it means that we are interactively organized. This means that many, many inputs from many, many ganglion "talk" about what is going on--there will not always be the exact "conversation" or reaction to the same stimulus. Behaviors can now be extremely varied and yet some things can be exactly the same all the time, such as walking patterns, or movements performed daily (such as getting dressed in the morning). But things can also be wildly different, not only between different people but on different days of the week when faced with the same stimulus--it all depends on what the corollary discharges are "saying" at the time. Behaviors can now be better explained because of these communications but it also becomes easier to see the varieties that we perceive in other's behaviors and our own idiosyncrasies.
Yep, CD's a lot like the various cues used by symphony players (though not necessarily like having a conductor). Nice analogy. And yes, can make life more interesting, differences among people as well as in one's self. PG