A commonly held belief , first proposed by Dr. Paul Ekman, posits that there are six basic emotions that are universally recognized and easily interpreted through specific facial expressions, regardless of language or culture. These are : happiness , sadness , fear , anger , surprise and disgust.
New research published in the journal Current Biology by scientists at the University of Glasgow has challenged this view and suggested that there are only four basic emotions .
His conclusion was reached by studying the variety of different muscles in the face – or units of action as researchers refer to them – involved in signaling in different emotions, and the period during which every muscle is activated .
This is the first study to examine objectively the ” temporal dynamics ” of facial expressions , which are possible using a single platform Cara generative grammar developed at the University of Glasgow.
The team from the Institute of Neuroscience and Psychology assertion that while the signals of facial expression of happiness and sadness are clearly distinct over time , fear and surprise share a common signal – eyes open – early dynamics signaling .
Similarly, anger and disgust share wrinkled nose. Are these early signs that could represent the most basic warning signs . Later in the dynamic signaling , facial expressions convey signals that distinguish the six ‘classic’ facial expressions of emotion.
Lead researcher Dr Rachael Jack said : “Our results are consistent with the predictions of evolution, where the signals are designed by the biological and social evolutionary pressures to optimize its function .
” First, the signs of early danger give the best benefits to others , allowing faster escape Secondly, the physiological benefits for expresser – . Wrinkled nose prevents the inspiration of potentially harmful particles, while much of eye consumption increases the useful visual information for escape – is better when facial movements are made early.
” What our research shows is that not all facial muscles appear simultaneously during facial expressions, but rather develop over time supporting a biologically basic hierarchical information socially – . Specific time ”
In developing his research team used special techniques and developed at the University of Glasgow for the synthesis of all facial expressions software.
The generative grammar Face – developed by Professor Philippe Schyns , Dr. Oliver Garrod and Dr. Hui Yu – uses cameras to capture a three-dimensional image of the faces of the people specially trained to activate the 42 individual facial muscles independently .
From this a computer can generate specific or random facial expressions in a 3D model based on the activation of different units or groups of units actions to imitate all facial expressions.
By asking volunteers to observe the realistic model as it took several expressions – thus providing a true experience of four dimensions – and state that emotion is being expressed researchers are able to see which units specific action observers associated with emotions individuals.
It was through this method found that the signs of fear / surprise and anger / disgust mingled in the early stage of the transmission and only became clearer later when other action units were activated .
Dr. Jack said : “Our research casts doubt on the idea that human communication consists of six basic emotion categories, psychologically irreducible Instead it is suggested that there are four basic expressions of emotion. .
“We showed that facial expression signals ” core ” are perceptually segmented over time and follow a developmental hierarchy of signals over time – of biologically rooted basic to the most complex signals specific social cues.
“Over time , and that humans migrated around the world , socio-ecological diversity probably previously common specialized facial expressions, alter the number , variety and type of signals across cultures. ”
The researchers intend to develop their study observing facial expressions of different cultures , including East Asian populations to those who have already been compiled interpret some of the six different classic emotions – putting more emphasis on the signals from the eyes mouth movements compared to Westerners.