Faces communicate a wealth of information, including cues to others’ internal emotional states. Face processing is often studied using static stimuli; however, in real life, faces are dynamic. The current project examines face detection and emotion recognition from isolated motion cues. Across two studies, facial motion is presented in point-light displays (PLDs), in which moving white dots against a black screen correspond to dynamic regions of the face. In Study 1, adults were asked to identify the upright facial motion of five basic emotional expressions (e.g., surprise) and five neutral non-rigid movements (e.g., yawning) versus inverted and scrambled distractors. Prior work with static stimuli finds that certain cues, including the addition of motion information, the spatial arrangement of elements, and the emotional significance of stimuli affect face detection. This study found significant effects involving each of these factors using facial PLDs. Notably, face detection was most accurate in response to face-like arrangements, and motion information was useful in response to unusual point configurations. These results suggest that similar processes underlie the processing of static face images and isolated facial motion cues. In Study 2, children and adults were asked to match PLDs of emotional expressions to their corresponding labels (e.g., match a smiling PLD with the word “happy”). Prior work with face images finds that emotion recognition improves with age, but the developmental trajectory depends critically on the emotion to be recognized. Emotion recognition in response to PLDs improved with age, and there were different trajectories across the five emotions tested. Overall, this dissertation contributes to the understanding of the influence of motion information in face processing and emotion recognition, by demonstrating that there are similarities in how people process full-featured static faces and isolated facial motion cues in PLDs (which lack features). The finding that even young children can detect emotions from isolated facial motion indicates that features are not needed for making these types of social judgments. PLD stimuli hold promise for future interventions with atypically developing populations.

<p>Research on biological motion, using point-light displays to present the motions, have been unravelling what information factors are still embedded in those impoverished stimuli and which of these factors are essential in visual processing of biological motion. Earlier studies suggest that orientation is a crucial factor in biological motion processing. The short-term priming experiment presented in this paper will further investigate the legitimacy of the primacy of orientation and suggest different solutions based on contradicting findings in previously published studies.</p><p>In a serial two-choice reaction-time task, participants were presented with a patch-light display of a human engaged in one of three possible actions: climbing up a rope, jumping jacks, and walking. Participants had to identify the in-plane orientation of the human figure emerging from the moving patch-lights. Reliable facilitation effect was established for transitions containing same-oriented upright trails and same-oriented inverted trials. Interestingly, transitions of same-oriented upright trials produced significantly greater facilitation effect than transitions of same-oriented inverted trials.</p>

Research on biological motion, using point-light displays to present the motions, have been unravelling what information factors are still embedded in those impoverished stimuli and which of these factors are essential in visual processing of biological motion. Earlier studies suggest that orientation is a crucial factor in biological motion processing. The short-term priming experiment presented in this paper will further investigate the legitimacy of the primacy of orientation and suggest different solutions based on contradicting findings in previously published studies. In a serial two-choice reaction-time task, participants were presented with a patch-light display of a human engaged in one of three possible actions: climbing up a rope, jumping jacks, and walking. Participants had to identify the in-plane orientation of the human figure emerging from the moving patch-lights. Reliable facilitation effect was established for transitions containing same-oriented upright trails and same-oriented inverted trials. Interestingly, transitions of same-oriented upright trials produced significantly greater facilitation effect than transitions of same-oriented inverted trials.