A professional ballerina trains for years to learn to gain ultimate control over her body in terms of muscles, flexibility and learning the basics of the classical dance. Time and time again in the standard "arabesque" which accompanies each warm-up and performance...she raises her left leg in opposition to her right arm and vice versa. However, upon taking a modern dance class of different style where there are different conventions, she finds it difficult to raise right leg with right arm for instance. It's almost as if her body is discouraging her from this movement. But why? One would think that due to such a remarkable life of training that such an elementary movement would not cause her to think twice. The answer to this riddle is exactly what we have discussed in class...Central Pattern Generation and Motor Symphony movements.

Central Pattern Generation is the human body's remarkable ability to play out a motor symphony of movements in absence of any input from the body or the external environment. As discusseed in class, this can be seen clearly in isolating the nervouse system of a crawfish (without skin, muscles...etc.) As a result, we see that patterns of the crawfish nervous system movement can be observed and emerge without any other stimuli. In addition, stimulating the axons in a random order can result in the old pattern of movement.

Many refer to this as "learned behavior". As with the dancer, actions performed over and over again seem to create a "musical score" for the axon's motor symphony whichgets stored away. However, this explanation does not account for behavior displayed such as this foer the first time...such as the cricket's mating chirp. How does it first know when and how to chirp?

Whether this Motor symphony and Central Pattern Generation is a type of musical score stored in our Nervous System memory, sent through genetics or falls somewhere in between, I can not be sure of thus far in my research of CPG and MS characteristics. However, I am assured that SOME type of internal organization exists within the Nervous System. It seems as though we have stumbled upon yet another "box within a box". The questions which arise in my mind however are WHERE this information fore CPG is stored?How is the signal to react turned ON and OFF? And WHAT causes it to be turned on and off? These two characteristics have effected my view of the human Nervous System by taking it to such an arbitrary, microscopic sub-sub-box level, that complete comprehension seems intangible to the human mind. As for the ballerina, she will just have to un-learn and re-learn any new "basics" for the time being. And although she may seem frusturated by it initially, to stop and think about why such "control" over her body has resulted in such a lack of "control" may help the realization of a dimension of memory she has never pondered before.

The ballerina example a delightful and highly appropriate one. Yes, because of CPG's (among other things) movement has to be unlearned to be learned. And that insight does help (me at least) to bridge between the "arbitrary, microscopic, sub ..." to things that are demonstrably behavior. Doesn't do that for you? PG