Motion contributes to the interpretation of emotional facial expressions

Abstract

Most research on expression recognition uses still photographs of high emotional intensity expressions, whereas in real life expressions tend to be dynamic and of low emotional intensity. The present study uses photorealistic 3-D animated images of ecologically valid expressions (Spencer-Smith, et. al., 2000) in a seven-alternative forced choice task. We demonstrate that very low emotional intensity expressions are accurately identified when presented in a dynamic fashion, while accuracy with static displays are near chance. Additionally, sad expressions are identified either as sad or happy depending on the direction of presentation (increasing or decreasing emotional intensity). In two experiments, participants viewed pairs of images of low emotional intensity expressions (anger, disgust, fear, happiness, sadness and surprise) presented serially in three display conditions. In the first condition, stimuli were presented in the order lower intensity→lightly higher intensity, resulting in apparent motion in the direction of increasing emotional intensity. In the second condition, intervening noise resulted in the perception of two static images; in the third, the stimuli were presented in decreasing order. Accuracies in the first condition approached those found for high emotional intensity static images in previous studies, while in the remaining condition accuracies were near chance. Sad expressions presented in the reverse order were identified as happy.