You can call it mental fatigue, but the performance coach and author Steve Magness uses the wild ending of the UConn-Duke NCAA tournament game to explain the dynamic further. Under pressure, our prefrontal cortex, which is the rational part of our brains, goes “offline,” and our stress hormones take over. As Magness notes, this is why Duke made a pass when it just needed to hold on to the ball, and it’s no different than a golfer going for a risky shot at a time when they’re better off laying up.