人类有21种表情
When you're feeling one of those combination emotions, like sadly angry or happily disgusted, it shows on your face in a unique way, a new study shows.
研究显示，当人们感受到上述复合情感时，例如悲愤或者又开心又讨厌，这些情感就会以一种特别的方式呈现在脸上。
In fact, there may be at least three times more recognizable human facial expressions than previously thought, the researchers said.
In a new study, researchers defined 21 facial expressions that we use to convey our emotions, and found that a computer model could tell them apart with a high degree of accuracy by looking for small changes in facial muscles.
Among these facial expressions were the six, long-recognized basic emotions -- happy, sad, fearful, angry, surprised and disgusted -- but also 15 others, which were a combination of these basic feelings. For example, a person may show that they feel happily surprised, or angrily surprised, said the researchers, calling such feelings compound emotions.
This extended library of facial expressions of emotions may be useful in studying human brain and social communication, as well as in the design of computer systems that can communicate with humans, researchers said in their study published today (March 31) in the journal Proceedings of the National Academy of Sciences.
"We've gone beyond facial expressions for simple emotions like 'happy' or 'sad.' We found a strong consistency in how people move their facial muscles to express 21 categories of emotions," said study researcher Aleix Martinez, a cognitive scientist and associate professor of electrical and computer engineering at The Ohio State University. "That tells us that these 21 emotions are expressed in the same way by nearly everyone, at least in our culture."