But how does the brain achieve both types of smiles using the same facial muscles? It all depends upon which part of the brain starts the smile.

　　If the brain's dopamine neurons (多巴胺能神经元) start the smile, then the smile looks sincere. If the brain's motor cortex starts the smile, in other words, if we are consciously willing ourselves to smile, then a slightly different set of facial muscles are actirated. It can be difficult to describe precisely how real and fake smiles differ, but we are all very capable at knowing the difference.

　　But can forcing yourself to smile produce the same kinds of good feelings as a real smile does?

　　Anything that prompts the release of dopamine in the brain brings pleasure.

　　For example,

　　cocaine and coffee both release dopamine in the brain.

　　The release of dopamine in the front half of our brain is accompanied by a real smile. But can this process be reversed? What about putting on that happy face? Can the simple act of smiling bring pleasure? Yes.

　　When we smile, fake or real, the contraction of the facial muscles slightly distorts (扭曲) the shape of the thin facial bones. This slight distortion in their shape leads to an increase in blood flow into the brain and then increases the release of dopamine.

　　As a result, walking around all day with a smile on your face will make your mood happier. Not only will you be happier but your smile might lead to the release of dopamine in someone else's brain—now that truly shows the power of a smile.

【2017届浙江省高考英语一轮复习训练：必修四 Unit 4《Body language》】相关文章：

★ 2017届江苏省淮安市新马中学高考牛津译林版英语一轮复习活动单：模块6 Unit 3《Understanding each other》

★ 2017届江苏省淮安市新马中学高考牛津译林版英语一轮复习活动单：模块7 unit 3《The World online》

★ 【浙江专用】2014届高考英语一轮复习课时作业(二十五)必修5Unit 5《First aid》

★ 【三维设计】2017版（江苏专用）二轮复习练习：必修4 Unit 1《Advertising》单元检测（含解析）

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修4 unit4《Body language》

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (33)

★ 湖南省岳阳市2014高考英语一轮单项选择训练题（12）及答案

★ 2014年牛津译林版高中英语总复习（第1轮）同步练习 M4《Unit 3　Tomorrow s world》

★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ规范练：6（含解析）

★ 2014年牛津译林版高中英语总复习（第1轮）同步练习 M4《Unit 2　Sports events》