Scientists have discovered why the Mona Lisa's expression looks so different to different people and at different times.

不同的人在不同的时间观察蒙娜丽莎的表情会得到完全不同的印象，对于这一点，科学家们已经找到其中的原因。

For centuries, art lovers and critics have been perplexed¹ by and debated the Leonardo Da Vinci paintings gaze and slight smile - or is it a grimace²?

几百年来，艺术爱好者和评论家一直对莱奥纳多?达芬奇这幅画中人物的目光和她的微笑（或是苦相？）感到困惑，并对此进行争论。

But new research from the University of California, San Francisco has shed new light on the luminous³ and seemingly changing face of the Mona Lisa.

不过，美国旧金山加利福尼亚大学的一项新研究让人们对蒙娜丽莎明亮且似乎在不断变化的表情有了新的理解。

Through experiments on visual perception and neurology, they discovered that our emotions really do alter how we see a neutral face.

通过视觉和神经学实验，科学家们发现，我们的情绪确实可以改变我们看待一个中性的脸部表情的方式。

Dr Erika Siegel and her colleagues study how our emotions change our perceptions of the world around us - even when we aren't aware that something has changed our feelings.

来自该大学的埃丽卡?西格尔博士及其同事研究情绪如何改变我们对周围世界的理解，即使我们不知道某些事情已经改变了自己的情绪。

This relies on the modern theory of 'the brain as a predictive organ, instead of a reactive one,' says Dr Siegel.

西格尔说，这基于“大脑是一种预测性器官而非反应性器官”的现代理论。

In other words, 'we have a lifetime of experience and we use those experiences to predict what we are going to experience next. '

西格尔解释说，换言之，“我们积累了一生的经验，并使用这些经验来预测接下来将要经历的事情。”

'Incoming information is actually just used to correct the predictions if they turn out to be wrong,' Dr Siegel explains.

“如果这种预测被证明是错误的，新的信息实际上只是用于纠正预测。”

So, she and her team predicted that how we perceive a new face - as happy, sad, friendly, neutral - actually has a lot more to do with the feelings we are carrying around when we greet it than the expression on that face.

因此，西格尔及其团队预测，人们对一张新面孔——究竟是愉快、悲伤、友好，还是中性——的理解，实际上会更多地与我们遇见这张面孔时自身的情绪有关，而不是这张面孔的实际情况。

Dr Siegel and he team can actually simulate that subconscious⁴ experience of our feelings thanks to a trick our vision plays on us.

实际上，西格尔的团队利用视觉可能欺骗我们的原理模拟出了人类情感的潜意识经验。

We all have one dominant⁵ eye and one more passive non-dominant one.

每个人都有一个主视眼和一个更加被动的非主视眼。

If each eye is receiving different information, we only consciously perceive what dominant one sees. But non-dominant sights can still seep⁶ into our subconcscious.

如果两个眼睛接收到的信息不同，那么我们下意识地只接受主视眼所看到的情景。但非主视眼所看到的信息仍然会留在我们的潜意识中。

Dr Siegel and her team use this to gently and prime their study participants to feel one way or another.

西格尔的团队利用这一点小心地引导，让研究参与者产生不同的感觉。

They showed 43 people two sets of flashing images simultaneously⁷, so that the dominant eye saw and registered neutral expressions, while the non-dominant eye 'saw' flashes of neutral, grimacing⁸ or smiling faces, that they would only subconsciously⁹ be aware of.

他们向43人同时展示两组一闪而过的照片，以便让主视眼看到并记下中性表情，同时让非主视眼“看到”中性、苦笑或微笑的面孔，而参与者只能下意识地明白这一点。

After viewing the flashing faces, the researchers showed the participants options of faces and asked pick out which ones they had seen.

在看过这些一闪而过的面孔后，研究人员让参与者看面孔图片，并让他们挑选出哪些是曾经看到过的。

When their non-dominant eyes had seen a happy face, they were more likely to think the neutral face had actually been smiling, and the same was true for grimaces¹⁰ and neutral faces.

当参与者中非主视眼看过的是笑脸时，他们更倾向于认为中性面孔实际上是在微笑。而对于看到了痛苦和中性表情的面孔的参与者，他们也有同样看法。

This means that 'if you see the Mona Lisa after you have just had a screaming fight with your husband, you're going to see [the painting] differently,' says Dr Siegel.

西格尔说，这意味着“如果一个人刚刚同丈夫大吵一架，那么在她看到蒙娜丽莎这幅画后会有不同的理解”。

'But if you're having the time of your life at the Louvre, you're going to see the enigmatic smile,' she adds.

她补充说：“但如果你正在享受卢浮宫的美好时光的话，那你便会看到蒙娜丽莎神秘的微笑。”

'We are the architects of our own experience. Our brain makes predictions about what it expects to see and uses information from the world to update its expectations,' Dr Siegel says.

西格尔说：“我们是我们自身经历的建造师。我们的大脑对即将看到的场面做出预测，同时用外部世界的信息更新预测。”