Ever had the following happen to you or heard of it happening to someone else. You are sparring at a tournament and really getting into the fight. Suddenly, it seems that everything is happening in slow motion, giving you plenty of time to block and attack. It all seems so effortless. Alternatively, you are really into a fight, and suddenly it is over; you cannot believe it went so quickly.
There is a term for this phenomenon; it is called tachypsychia, a neurological condition that distorts the perception of time, usually brought on by physical exertion, physical stress, drug use, a traumatic event, or a violent confrontation. It is believed to be caused by a combination of high levels of dopamine and norepinephrine in the body.
When under the effect of tachypsychia, perceived time may lengthen (brought on by the increased brain activity caused by epinephrine), making events appear to slow down; or perceived time may contract (caused by a severe decrease in brain activity caused by the "adrenaline dump"), making events appear to move in a speeding blur. Martial arts instructors often call this effect the Tachy Psyche effect.