Emotional expressions with minimal facial muscle actions. Report 2: Recognition of emotions

We tested the hypothesis that an emotion expressed by a still-face person keeping direct gaze can be adequately recognized. The prospective study involved 800 volunteers as judges (age 16–25). All the judges were presented with three 10-picture sets of still faces expressing angry, sad, and happy emotions by vivid gaze only. The first 10-picture set consisted of full faces, the second set consisted of the middle part of the face pictures, and the third set presented the eyes only. Half of the judges (Group 1, n = 400) were asked to label the pictures as Angry, Sad, or Happy. Another 400 judges (Group 2) were asked to label the same pictures as Angry, Sad, Surprised, Frightened, or Happy to validate the selected sets of pictures. Group 1 judges presented correct recognition of the emotion in 72% for full-face pictures, 73% agreement for middle parts, and 68% agreement for the eyes only, while in Group 2 the agreements were 63%, 68%, and 48.5% respectively. After Bonferroni correction for multiple comparisons, our results show that the gaze was the only emotional cue in all tests and the presented emotions were recognized with relatively equal degree of success. We confirm our initial statement (Report 1) that the expression of an emotion can be adequately achieved with minimal facial muscular involvement when predominantly the gaze expresses emotion. In most of the cases, an “emotional gaze” during a still-face or static face situation is adequately recognized by people but the emotion recognition skill has individual variations.