There have been two fascinating articles published in the past few days talking about how we perform under pressure. Both are fascinating reading.
In the first, The Guardian examines why athletes choke. The short answer: you think too much. When you're a master athlete, you have muscle memory and your actions are literally built into your body. If you think too hard about what you're doing your brain, rather than your muscles, takes over and you fail.
The second article is the Times talking about how some soldiers seem to have a sixth sense for danger. In this instance, the brain is processing images subconsciously faster than it can consciously. Humans appear to build a subconscious model of normal situations and tiny variations of this can be sensed sometimes preattentively (this isn't magic; the Gestalt philosophers knew this).
There's a chemical element at play in the Times article too: Navy Seals under pressure release the same amount of cortisol as normal soldiers, but they are able to recover to a normal level much faster.
I've no idea how to interpret all of this, but there are some interesting themes. Training makes it easier for you to recover to normal faster, meaning that you can use your muscle memory rather than having to think? A well-developed mental model makes it easier for you to find patterns and deviations from that pattern, meaning that you can then respond more quickly without thinking? Anyone want to speculate?