This discussion has many facets to it and has the potential of becoming the longest thread in BB history. In focusing on what I first mentioned, I think that the benefits of kata cannot be entirely recognized since most of the development occurs beyond the reach of our awareness - at the spiritual level if you will.
The process of filtering stimuli for instance
occurs differently for everyone. Through time, our brains naturally put up barriers against 'unimportant' stimuli in order to control our anxiety and stress. Noises, variations in lighting,slight changes in temperature and even minor changes in our own body chemistry are filtered out daily, never to become a part of our awareness. There are simply too many things which occur around us and within us that paying them attention would lead to total mental exhaustion after only a few minutes. Filtration is a necessary development for our survival when things are calm and we are not under assault, but there is, as always a downside. Through the process of filtration, we become, disconnected from ourselves. A divide is developed between mind and body and we suffer through our loss of 'self control'. Many of us exist in this world without a sharp edge, victims of our inadvertant disconnection. This is particularly dangerous, for instance when we are battling for our lives. Many refer to the disconnected mindset as being 'HUA' or of course 'head up a**'. We will do a lot of stupid thing while we have HUA.
I think the state of mind that kata encourages brings down these barriers temporarily and allows the unobstructed neurons to send and recieve messages in a different more natural way. The brain is turned on to it's potential (we estimate that only about 4% of our brains potential power is ever really used)and becomes a conduit between the world and ourselves. In doing this, the body and mind become re-connected and biofeedback is possible. This movement from Beta to Alpha brain waves occurs with some kata, if it is done correctly. This process can be measured with sophisticated apparatus, proving that something occurs in the mind of the performer that support my position, at least scientifically.
The process of 'moving meditation' I mentioned presupposes a trancelike state of mind that overcomes the practitioner and begins to do it's work, silently on the mind of the performer. There will be no feeling of this process working... as it does not occur at the mental level. In fact it occurs in spite of the mind. It's like cleaning the junk off of your hard drive. While this process is underway, the computer is unable to perform it's computations. But the process can be recognized over time by a feeling of well bing and relaxation that accompanies a thorough cleansing of stress and anxiety, the 'junk' of the mind.
Training in kata, therefore is also training for combat. When the battle occurs, it is important that the fighter be able to enter this state of mind where he is unobstructed by thought, stress and anxiety. The heartrate, uninfluenced by stress remains at a manageable rate If the fighter is in the 'kata' mndset, then he is functioning purely from the training of technique which, unobstructed should be powerful, crisp and deadly.
BTW, Thanks for your responses. They are very thought provoking.