In general, corollary discharge signals help to understand inconsistent behaviors in experimental conditions where everything is pretty much controlled for, but differences still occur between trials. One thing that I'm not certain about is the connection of the corollary discharge with the I-function. One interpretation is that corollary discharges are spontaneous excitations of the neuron that lead to output occurring without any related input. Or, could it be that corollary discharges are related to an organism's predispositions, such as their genetic makeup or experiential influences. The second idea seems like it would have more influence on output by the effects it has on the processing of specific inputs. But maybe this is an additional aspect of corollary discharge. I guess I'm just not sure how encompassing the idea of the corollary discharge really is. Overall, it does help in my understanding of behavior, but I think it would help more if I had a better understanding of it.
Fair enough. Has gotten any better since you wrote this? Regardless, your prior points quite good ones. Yes, CD could help account for variations in behavior which don't seem to have any explanation in terms of input signals. And, they don't bear any clear relation to the "I-function", which is to say they can exist independently of it (but also might contribute to it, and be a tool of it, as we'll come to later). How encompassing an idea? The strict definition of the term is "signals generated by pattern generating circuitry which go to circuitry other than motoneurons and influence their function". They might, or might not, arise spontaneously. It is worth, though, thinking about intercircuit coordination in cases in additional to pattern generating circuitry, and how this might help to explain behavior. That help? PG