My question to you all is this...what training can be used to get over the psychological barriers that are placed on a person in a moment of crisis.
IMHO, just physical training does not necessarily overcome psychological barriers.
Like physical training, one can also mentally/psychologically/cognitively train and change.
Like physical training slow down and be mindful of the thoughts which create the fear response (psychological barriers), moving away from. Step out and dissociate from them (see youself). Replace them with love based thoughts (courage), moving towards. Step into and associate inside them (as if you were seeing, hearing, feeling) as if you were there. Hold these positive courage-based thoughts while you train.
Slow conscious repetition will change the neuropathways through neuroplasticity until it becomes the normal firing path.
Meditation is a passive way of calming the mind and also teaches more mental control and discipline. Very useful.
Hope that helps in some way to answer your very large question.