What F.M. Alexander discovered was how to consciously interrupt (and therefore change) even long-held patterns of thought and movement.
Alexander discovered that if he made it his priority to prevent unwanted or automatic reactions at what he called the “critical moment,” this would free him to substitute a response of his own choosing.
By first practicing this new result in his mind, he was able to always reinforce success (exactly the opposite of the very well-named method of trial and error.)
This describes the long-resisted notion that the brain has a built-in flexibility of function that allows it to actually rewire itself when adapting to changing conditions.
Thoughts can cause changes in the body as well as in the brain. Alexander technique (AT) teachers have learned to make these changes consciously.
The same neural pathways are used whether in just thinking about something or when actually doing it. In fact for most people, the boundary is fuzzy enough that their muscles actually become involved in thinking.
Simply thinking about a stressful situation, even one long since over with, is able to provoke a stiffened neck and furrowed brow.