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Room
Seezimmer 3
Friday, September 14  »  8:45 - 10:00
Symposium 17
Processing of identity, emotion, and gaze direction in faces
Host
Adrian Schwaninger (University of Zurich)
Chair
Adrian Schwaninger (University of Zurich)
Discussant
Claus-Christian Carbon (University of Vienna)
In this symposium, recent findings regarding the processing of identity, emotion, and gaze direction in faces are presented and discussed. As introduction, a recent review paper on a psychophysical, physiological and computational perspective on processing of information in faces is presented (Schwaninger et al., 2006, Progress in Brain Research, 156, 321-343). The importance of configural processing for face recognition is illustrated by a study involving patients with congenital prosopagnosia (Carbon, University of Vienna). Using computer graphics techniques, it is investigated what facial regions must move for dynamic conversational facial expressions to be recognized (Cunningham, University of Tübingen). The role of configural processing for recognition of emotional expression in faces is examined using composite faces and computer graphics (Chiller-Glaus, University of Zurich). Finally, it is shown that emotional expression modulates perceived gaze perception (Lobmaier, University of St. Andrews). Altogether, these different studies show the benefit of combining different methods from experimental psychology, computational modelling, neuropsychology, and computer graphics to gain a deeper understanding of the processing and representations used in processing information contained in faces.
Speakers
Claus-Christian Carbon
Which specific processes are impaired in congenital prosopagnosia (face blindness)?
Authors
Claus-Christian Carbon (University of Vienna)
Prosopagnosia (PA), sometimes termed as “face blindness”, is a disorder concerning the recognition of familiar faces. Face research discriminates between an acquired (aPA) and a congenital form of prosopagnosia (cPA). Here, we focused on the underlying processes that are impaired in cPA, which enables to identify processes which are suspected to be the essential ones for processing faces on an expert level. Experiment 1 used a simultaneous matching task in which faces and houses were used as stimuli. Both object classes varied by relational, featural or local (colour) aspects. Only for faces but not for houses, people with cPA were severely impaired in recognition of stimuli which varied by relational aspects. In Experiment 2, participants had to detect Thatcherised faces (Carbon and Leder 2005) in a speeded recognition task. For people with cPA, our data showed a strong linear relationship between the deviation of the presented faces from an upright orientation and RT. In contrast, the controls’ data revealed a sigmoid function of RT. This indicates that cPA is based on impairments of configural/holistic face processing. In sum, configural/holistic processing seems to be a key processing mode with respect to general face processing and what we call ‘face expertise’.


Carbon C C, Leder H, 2005 "When feature information comes first! Early processing of inverted faces" Perception 34 1117-1134
Douglas Cunningham
Computer graphics and the components of dynamic facial expressions
Authors
Douglas Cunningham (University of Tuebingen (D))
Christian Wallraven (Max Planck Institute, Tuebingen (D))
Despite the prevalence and importance of facial expressions, our understanding of, and our ability to artificially synthesize, them is limited. Both humans' amazing expertise at recognizing facial expressions and the sometimes extremely subtly nature of the physical differences between very different expressions make the recognition of facial expressions arguably one of the most difficult tasks the human visual system can perform. The abundance of information present in a photograph of a facial expression, let alone in a recording of a dynamic expression, encourages one to draw a distinction between the information that is present in a specific recording of an expression and the information must be present for that expression to be recognized. Here, we present a brief overview of some empirical work, using various computer animation techniques, aimed at determining what facial regions must move for dynamic conversational facial expressions to be recognized.
Sarah Chiller-Glaus
Investigating holistic processing of facial emotion using 3D computer-graphics
Authors
Sarah Chiller-Glaus (University of Zurich)
Mario Kleiner (Max Planck Institute, Tübingen)
Franziska Hofer (University of Zurich)
Barbara Knappmeyer (New York University)
Adrian Schwaninger (University of Zurich and Max Planck Institute, Tübingen)
Using a paradigm by Young, Hellawell, and Hay (1987), we tested recognition performance of aligned and misaligned composite faces with six basic emotions (happiness, fear, disgust, surprise, anger, sadness). Stimuli were created using 3D computer-graphics and they were shown as video sequences (moving condition) and static peak expressions (static condition). The results revealed that misaligned composites were better recognized than aligned composites. If the two halves were aligned, a new emotion resembling each of the two originals seemed to emerge, suggesting holistic processing. This made it difficult to identify the emotions from either half. If the top and bottom halves were misaligned horizontally (impairment of holistic processing), then the two halves did significantly less fuse to create a new emotion, and the constituent halves remained identifiable. Whereas moving stimuli were better recognized than static faces, there was no interaction between motion and alignment. Thus, facial expression processing is holistic in static and moving faces. The results are discussed in relation to a model which integrates featural and configural information for a holistic percept.
Janek S. Lobmaier
Emotional expression modulates perceived gaze perception
Authors
Janek S. Lobmaier (University of St. Andrews (UK))
David I. Perrett (University of St. Andrews (UK))
Eye gaze perception is an import social skill. The direction of gaze portrays information about what another person is attending to. Various factors have been reported to influence the interpretation of gaze perception, such as for example the iris/sclera ratio, head direction, and the presence of objects in the attended space. Here we show that gaze perception is also influenced by the emotional expression of a face. In a forced choice yes-no task participants were asked to judge whether a presented face was looking at them or not. Four faces were used as stimuli, each expressing four different emotional expressions (angry, fearful, happy, and neutral) in different viewing angles. The data revealed that happy faces are relatively more likely to be judged as looking straight at an observer than angry, fearful or neutral faces. These findings are discussed on the background of the self-referential positivity bias.
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