The concept of central pattern generation and corallary discharges seems both absolutely amazing and yet completely logical to me. The idea of such a delicate and complex amount of control existing in the nervous system seems flabbergasting, but it's form and system are so clearly functional that it removes the mystique. It follows perfectly the metaphor of communicating boxes made out of smaller boxes that comprises the brain and nervous system.

This gives much credence to the old cliche "practice makes perfect" in that the continued use of a CPG and the corollary discharges would naturally lead to increasing accuracy of movement. It also helps me to understand why it is that memory of physical movement such as tying shoes is not affected in the same way that memory of intellectual things such as dates, names, etc. Movement and actions that are performed without thought, such as absent mindedly scratching an itch, or sleep walking, are easy to account for in terms of monitoring by corollary discharges and CPGs.

One thing I am curious about in relation to the subject of CPGs is the length of time that the pathways are in exsistence when not in use. Another cliche pops into mind, 'It's like riding a bike; once you learn you never fall off.' Is this true, do you never forget? No, this can't possibly be true, after all, it only takes a couple of months of not playing a guitar to lose the ability to perform anywhere near the former level. Perhaps this is related to the complexity of the pattern. Hmmm. Just a thought.

And what's the deal with complexity, anyhow? Does something really complex mean that it has a lot of associated actions, or that it requires more concentration? Is tying a knot more complex a movement than splitting a hair? I guess I would need to define complexity before I rambled on too much farther, so I won't go too far. But it seems as if the level of complexity in the really vague way that I am thinking of it may be measured in the amount of corollary discharges needed. But then again, I'm also combining proprioception, CDs, and autonomy. I guess I'm not being coherent enough to continue this, but that's my question about behavior... I guess... sort of.

No need for diffidence. An interesting and appropriate line of thinking. But you need to fill in some details. How does CPG and CD help with "practice makes perfect"? Yes, it does suggest a difference between some kinds of memory/skills and others (we'll talk more about this in a while). And that does lead on to why some things are more stable, others less so (will do some of this, but there's lots of room here for you/others to come up with new ideas). As for complexity ... that too is open and interesting turf. Yes, I suspect there is SOME relation to numbers of semi-autonomous parts, and hence to importance of interactions (communicating pathways, CD's). PG