Ian: Ok, presuming that your horse is like most horses when unafraid (is breathing nicely, has a soft eye, doesn't cause his ears to go rigid, doesn't crank his tail or raise his head to giraffe height, etc.)
The question is: What is the first sign your horse gives that he's scared?
It begins with an increase in his awareness on something other than being centered in himself and right there with you.
Before the ears & head, is there a tensing of the fascia (external muscles) and/or a holding of the breath? Or, have you not observed whether either of those precede the ears & head?
Ian: What signaccompanies the awareness of something uncentering to the horse? Just asking you to meditate on the first sign, before the "bigger" signs (again, I'm not sure of the answer, but someone here might hit upon it very clearly, then we'd all profit, or at least I would, since I didn't like getting spun off the horse!)
It really depends on the horse, they are all individuals and will all respond differently to different things. I guess I just don't get what you are asking for, since there is no hard and fast thing "all" horses do exactly the same.
Ian: What sign accompanies the awareness of something uncentering to the horse? Just asking you to meditate on the first sign, before the "bigger" signs (again, I'm not sure of the answer, but someone here might hit upon it very clearly, then we'd all profit).
The ability to recognize it is like a 'learned instinct' and it's born of experience. The more you have, the sharper it becomes. It's one of those things where intellectual understanding and 'knowing' are somewhat the same, but not really the same. There's knowing, and then there's -knowing-.
Ian: you say that experience teaches you to recognize it sooner; yes, no doubt! Yet, what is the sign, the "it" that you recognize first, before your horse spins a 180?
How helpful it'd be to hear what that first sign is!
But that's just it, there isn't ONE specific thing that ALL horses do. You have already been told different things that different people see on different horses...there's your answer. You have to learn what YOUR horse does.
I think that I have the answer, helped by Ian's answers, especially his last: the first sign that your horse has lost his inner ok-ness is a loss of his ATTENTION being "centered within himself", as Ian said, as well as his attention being with YOU, as Ian likewise said. Dr. Deb Bennett calls the horse's attention the "birdie", which is a good description, because the only time that the horse is ok is when his birdie hasn't flown off yonder. So we must be perceptive enough to see that his attention has flown to something in the environment, prior to any physical sign or action.
I wasn't perceptive to my horse's attention shift, before he spun his 180, e.g.