[gibson_mandolins]

Your concious mind is not able to do 2 operations at the same time...people that claim that they can multi-task, over-estimate their abilities.
If you are concentraing on the technical aspects of playing the notes, your concious emotions are unable to feel the music that you are playing.
After much practice, the technical side becomes a subconcious activity and you are able to concentrate on your musical expression, through your emotions. I believe that it occurs with many activities. It happened to me when I learned how to surf...yeah emotions do occur with that activity.

pretty much this. When you are first learning the guitar your mind is concerned with how to play something. as you get better you think more of what to play