Norepinephrine provides another boost. In the body, it speeds up heart rate, muscle tension, and respiration, and triggers glucose release so we have more energy. In the brain, norepinephrine increases arousal, attention, neural efficiency, and emotional control. In flow, it keeps us locked on target, holding distractions at bay. And as a pleasure-inducer, if dopamine’s drug analog is cocaine, norepinephrine’s is speed, which means this enhancement comes with a hell of a high.