When I am in the zone playing COD for instance, I can run into a room, see three people and determine an optimum shooting strategy in under a second. For instance, if one guy is turned I can shoot him last and instead shoot the closest then the second determine the best place to duck to reload if needed. All the while, I process sound from everywhere else, keep a running map in my head (I'm very good with spatial orientation) and can check off where explosions have taken place or possible spawn points coming up.
I can also tell the difference between a player with an 80ms ping and a 30ms ping.
This all comes with a caveat. I have been playing for ~8 years off and on so I have experience and confidence in my abilities. Also, to achieve such a state to determine split second actions, my heart rate is well above a sedentary resting state. Once I figured this out, I stopped playing as much as I can only assume that the adrenaline rushes from gaming while sitting can only be bad for my health.
Two cents..