Passage 2

The habit-forming process within our brains is a three-step loop(回路). First there is a cue,a trigger that tells your brain to go into automatic mode and which habit to use. Then there is the routine, which can be physical or mental or emotional. Finally, there is a reward, which helps your brain figure out if this particular loop is worth remembering for the future. Over time, thisloop—cue, routine, reward — becomes more and more automatic. The cue and reward become intertwined(交织)until a powerful sense of anticipation and a desire appears. Eventually, a habitis born.

Habits aren't destiny. Habits can be ignored, changed, or replaced. But the reason why thediscovery of the habit loop is so important is that it reveals a basic truth: When a habit appears,the brain stops fully participating in decision-making. It stops working so hard, or shifts focus to other tasks. So unless you deliberately fight a habit — unless you find new routines-the patternwill unfold automatically.

Habits never really disappear. They're encoded(嵌入)into the structures of our brain,andthat's a huge advantage for us, because it would be awful if we had to relearn how to drive afterevery vacation. The problem is that your brain can't tell the difference between bad and good habits; and so if you have a bad one, it's always lurking(隐藏)there, waiting for the right cuesand rewards.

This explains why it's so hard to create exercise habits, for instance, or change what weeat. Once we develop a routine of sitting on the sofa, rather than running, or snacking whenever we pass a doughnut box, those patterns always remain inside our heads. By the same rule,though, if we learn to create new neurological(神经系统的)routines that overpower those behaviors — if we take control of the habit loop - we can force those bad tendencies into thebackground. And once someone creates a new pattern, studies have demonstrated, going for a jog or ignoring the doughnuts becomes as automatic as any other habit.

Of course, those decisions are habitual, effortless. As long as your basal ganglia(基底核)iscomplete and the cues remain constant, the behaviors will occur unthinkingly. At the same time,however, the brain's dependence on automatic routines can be dangerous. Habits are often as much a curse as a benefit.