Has anyone ever told you that you looked sad or tired when you weren’t? If the problem isn’t your mood, it might be your face, according to a study in the medical journal Plastic and Reconstructive Surgery.

Yale University researchers set out to determine how facial features like eyebrow shape, eyelids and wrinkles affect facial expressions. They took a photo of a woman’s eyes and digitally altered it to change the eyebrow or lid shape or add wrinkles. After producing 16 different versions of the same face, they asked 20 study participants to rate, on a scale of 0 to 5, the presence of seven expressions or emotions: tiredness, happiness, surprise, anger, sadness, disgust and fear.

What was surprising about the study is that many of the pictures that mimicked various plastic surgery procedures, such as eyelid surgery or brow lifts, actually generated worse scores, with study participants rating those faces as looking angry or tired.

For instance, drooping of the upper eyelid was the biggest indicator of tiredness, but a picture that simulated a type of eyelid surgery — involving the removal of excess skin from the upper eyelid — made the woman look even more tired and sad, the study participants reported. Raising the upper eyelids produced an increase in the perception of surprise and fear.

“A significant number of plastic surgery patients opt for eyelid surgery, forehead lifts and face-lifts not only for rejuvenative reasons, but to change an unattractive facial expression as well,” said Dr. John A. Persing, one of the study authors. “Our findings indicate that moderation is best when removing excess skin in the upper eyelid. You do not want to create an overdone look that actually makes you look more tired.”

Eyebrows made a big difference in how people perceived the mood of the woman in the picture. When the brows were lowered or slanted toward the nose, or when forehead wrinkles were added, ratings of anger and disgust increased.

Also, raising the outer corner of the eyebrows produced an increase in the perception of surprise. Raising the inner corner of the eyebrows away from the nose was perceived as a sad facial expression.

According to the American Society of Plastic Surgeons, more than 241,000 eyelid surgeries, 43,000 forehead lifts and 118,400 face-lifts were performed in 2007. But the study shows that people contemplating eye surgery should talk to their doctor about how a procedure might affect their facial expressions. And some people might want to think twice about eliminating some sets of wrinkles. One digitally-altered picture added crows’ feet — tiny wrinkles around the eyes — and received high ratings for “happiness.'’

“The eyes and their related structures nonverbally communicate a wide range of expressions that are universal to all people,” Dr. Persing said. “Therefore facial expression should be a factor in how patients and their plastic surgeons select various rejuvenation procedures. As our findings show, even the slightest modification can elicit profound changes in how others perceive us.”

有沒有這種情況？有人說你看起來悲傷或很疲倦，可是你實際并不是這樣。修復重建與整形外科雜志中登出一項研究成果表明, 如果你的心情并不是這樣，可能是你的面部表情"惹的禍"。

耶魯大學的學者們開始研究臉部特征如眉毛的形狀，眼皮和皺紋如何影響面部表情。他們拍下了一位女士眼睛的照片，然后通過數碼技術改變眉毛,眼皮的形狀或者增添一些眼角皺紋, 在同一張臉上制出十六張不同效果的照片，他們請20個人從0到5的范圍內打分評價七種表情或者情緒：疲倦，高興，驚訝，生氣，悲傷，厭惡和恐懼。

出乎意料的是, 許多副照片其實是模仿不同的整容手術程序作出來的，象眼皮手術或者提眉，而這些手術實際產生的效果并不盡如人意，人們給出的評價是整形過的臉看上去有的是憤怒,有的則顯出疲憊。

例如，上眼皮耷拉下來最能代表疲倦，但是一副照片是模仿一種眼皮手術-----從上眼皮除去多余的皮膚-----人們評價這樣使人看起來更疲憊或者沮喪。提高上眼皮則讓人呈現驚奇和恐懼的表情。

“大量的整容手術患者選擇雙眼皮手術，提額和面部除皺，不只是為了青春常駐，還是為了改善面部表情。我們發現去除上眼皮多余的皮膚時最好適可而止。不要去除得太多，否則會使你看起來更沒有精神。”這項研究的作者約翰波森博士說。

眉毛在人們解讀他人的心情上意義重大。如果眉毛低垂或者向鼻子方向傾斜，或者額頭上的皺紋增加，說明生氣或者厭惡情緒。

還有就是眉毛的外緣提升會顯得驚奇，內緣提升與鼻子的距離拉長則讓人顯得悲傷。

美國整形外科學會提供數據表明，2007年共做了241000例眼皮額手術，43000例提額手術和118400例面部除皺手術。但是研究表明，想要做眼部手術的人應該與醫生談談, 明白他們將要進行的手術會怎樣影響他們的面部表情。想要除去皺紋的人也要三思而行，因為一幅照片用數碼技術增加了眼角紋的長度----結果人們普遍評價照中人的情緒是“快樂”。

“眼睛及周圍的肌肉無聲地表達了許多種情緒，們們對這些情緒的理解是共通的。因此要做面部整容手術的人在選擇手術程序時，應該將面部表情作為主要考慮因素。因為研究發現，即使是很微小的修改也會改變人們對我們的心情的看法。”