Facial coding is the process of measuring human emotions through facial expressions. With facial expression analysis you can test the impact of any content, product or service that is supposed to elicit emotional arousal and facial responses. One of the strongest indicators for emotions is our face.
Turns out that algorithms fail basic tests as truth detectors, according to researchers who study theoretical factors of expression and the complexities of reading emotions at the USC Institute for Creative Technologies. The research team completed a pair of studies using science that undermines popular psychology and AI expression understanding techniques, both of which assume facial expressions reveal what people are thinking. People smile when they are angry or upset, they mask their true feelings, and many expressions have nothing to do with inner feelings, but reflect conversational or cultural conventions.
A method is presented for obtaining a seriesofsilhouettes that were analyzed as profiles of the human face. When depressed psychiatric patients smiled before and after electroshock therapy, a greater facial displacement was recorded after treatment. Controls did not show any trend in this regard.
A facial expression  is one or more motions or positions of the muscles beneath the skin of the face. According to one set of controversial theories, these movements convey the emotional state of an individual to observers. Facial expressions are a form of nonverbal communication.
Facial expressions that show emotion play an important role in human social interactions. In previous theoretical studies, researchers have suggested that there are universal, prototypical facial expressions specific to basic emotions. However, the results of some empirical studies that tested the production of emotional facial expressions based on particular scenarios only partially supported the theoretical predictions.
Look at the picture above. Do you think the young woman is surprised? You may be wrong.
These are all ways that we purposely manipulate the muscles in our faces to show another person a particular message, thought or feeling. These common facial expressions appear across all humans and some animals and were first outlined by Guillaume Duchenne and further elaborated on by Charles Darwin 2. There can be some subtle difference in each facial expression between individuals due to the variety of face shapes, injury or other interactants like drugs.
While conducting research on emotions and facial expressions in Papua New Guinea inpsychologist Carlos Crivelli discovered something startling. He showed Trobriand Islanders photographs of the standard Western face of fear — wide-eyed, mouth agape — and asked them to identify what they saw. Instead, they saw an indication of threat and aggression. But if Trobrianders have a different interpretation of facial expressions, what does that mean?
The most notable research into the topic came from psychologist Paul Ekman, who pioneered research into emotion recognition in the s. His team of researchers provided their test subjects with photos of faces showing different emotional expressions. The test subjects then had to define the emotional states they saw in each photo, based on a predetermined list of possible emotions they had seen prior.