... Still working on it ... (Updated: May 15, 2009)

Symposium 22
Dynamic visual communication displays and facial information

Chairs

Claude Baudoin , Université de Paris 13, Villetaneuse, France
Hervé Abdi, The University of Texas at Dallas, TX, USA

Introduction

Visual communication displays have been widely studied in ethology, both in various animal species and in humans. Recently, various studies in birds (i.e., craws, parrots, pigeons, etc.) or mammals (i.e., dolphins and non-human primates) have focused on behavioural and cognitive aspects of self and social recognition, using mirror-image stimulation and moving video images. From these studies, came important results concerning cognitive processes and their evolution. Parallel studies on monkeys also support the existence of cross-modal face/voice recognition, based on dynamic information, as it was shown in human infants and adults. Recent studies in non-human primates and in humans indicate that, among other body visual displays, facial ones are of particular interest in communication, and that, some common mechanisms may be used for the integration of facial dynamic information. Because it conveys identity and expresses emotions, the human face is a very active topic of research for various disciplines. When identity is concerned (i.e., for psychology or biometry), the invariant properties of the human face become the focus of interest. In this context and in many studies of face preferences (i.e., in evolutionary psychology), the stimulus studied consists almost exclusively of static images of faces. But the human face is also an important source of dynamical information because movement is crucial for the expression and transmission of social information such as mental states or intentions. As such, this dynamical information represents an essential component of social cognition and inter-individual communication and, in fact, early work in ethology integrated this dynamical information in models of communication rituals. However, the development of these early models was probably impaired by technical difficulties in manipulating dynamical information. Recently, better computer tools have facilitated the manipulation of dynamical information and this, in turn, could favour the development of new theoretical approaches in disciplines such as ethology. The main goal of this symposium is to present current important results and theories relative to movement for processing identity and emotions. This symposium is particularly relevant for ethology because it integrates, within an ethological problematic, several contemporary and complementary approaches, and it will be discussed how these approaches could be applied to other species.
  1. Visual communication displays, the role of dynamic information.
    Claude Baudoin
    University of Paris 13 & CNRS, Villetaneuse, France

    Visual communication displays were widely studied in ethology, both in various animal species and in humans. Recently, various studies in birds or mammals focused on behavioural and cognitive aspects of self and social recognition, using mirror-image stimulation and moving video images of self or of familiar or unknown conspecifics and provided information important for our understanding of cognitive processes and their evolution. Parallel recent behavioural and neurobiological studies on monkeys revealed, in addition, a cross-modal face/voice recognition, based on dynamic information, as it was shown in human infants and adults. Recent studies in non-human primates and in humans indicate that facial visual displays are of particular interest in communication, and that some common mechanisms may be used for the integration of information. Today, in a renewed theoretical context partially triggered by the appearance of powerful adapted tools (i.e., new models and software), facial dynamics and social information appear as a fascinating area for ethological studies. In this talk, I will present some of the recent integrative studies in this area of dynamical visual communication.


  2. Recognizing moving faces: A psychological and neural synthesis
    Hervé Abdi
    The University of Texas at Dallas, TX, USA

    Information for identifying a human face can be found both in the invariant structure of features and in idiosyncratic movements and gestures. When both kinds of information are available, psychological evidence indicates that:
    (1) dynamic information contributes more to recognition under non-optimal viewing conditions, e.g. poor illumination, low image resolution, recognition from a distance;
    (2) dynamic information contributes more as a viewer's experience with the face increases;
    (3) a structure-from-motion analysis can make a perceptually based contribution to face recognition.

    In this talk, I will present a model describing a distributed neural system for face perception, which can accommodate the psychological findings with moving faces. I will also present some recent experimental and neuropsychological evidence supporting this model.

  3. The many aspects of face dynamics: EEG-MEG studies of the perception of eye gaze in human
    Nathalie George
    UPMC, CNRS & INSERM, Paris, France

    Faces are the constant vehicle of identity and therefore they may appear to convey principally invariant information. However, faces are fundamentally dynamic stimuli comprising continuously changing information. In particular, eye gaze is an essential cue for non verbal communication, which, in combination with other facial cues such as emotional expressions, conveys essential information for adaptive social interaction. Functional brain imaging studies on the perception of eye movement in humans have recently been booming. These studies have shown that gaze direction is processed early in the brain and recruits brain regions traditionally associated with the higher processes of social cognition. Differential brain responses to direct and averted gaze may be related to the different social meanings of these distinct gaze directions. In this talk, I will present some recent studies that we have underwent to characterize the neuro-cognitive substrates of perception of direct and averted gaze. These data concur with others to show that the perception of biological motion, or of the implied motion of static but intrinsically dynamic stimuli, may be an essential component of the understanding of others constitutive of social cognition, and that this information may be extracted very early on by the brain during face processing.


  4. Movement and the different signals in faces
    Markus Bindemann
    The University of Glasgow, Glasgow, UK

    Several important sources of information from faces are conveyed though movement, for example speech and expression. However, it is less clear that an individual's characteristic motion patterns convey much information about their identity. Instead, movement may provide the viewer with an opportunity to discard image-level information from successive 'snapshots' of a face, and hence to construct a more robust representation of that face. In this talk I will draw on studies of security surveillance, and examine whether there is really anything to be gained from trying to link an individual's characteristic movement to his or her identity.