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The Display of Emotion
Brent Lance
CS 543 Lecture
5/23/2017 7:32 PM
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1
Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through Nonverbal
Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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2
Motivation
 What is interesting about the display of
emotion?
 The development of Virtual characters
 Believable
 Capable of open-ended interaction
 Engaging
 For this, a character must be able to signal its
internal state through its external behavior
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Virtual Characters
 Keyframe Animation
 Classic technique from 2D cell animation
 Skilled animator develops key frames
 Interpolation between them creates
movement
 Slow, iterative process
 Produces most realistic behavior
 Takes very long time to develop
 Animations are not reusable
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KeyFrame Animation
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Motion Capture
 Motion Capture Animation
 Cameras record movement of sensors placed on an
actor
 Software reconstructs movement and approximation
of character’s anatomy
 Allows for quicker generation of movement
 Requires expensive hardware and analysis tools
 Captured sequences not reusable
 Can be difficult to retarget capture motion to 3D
model being animated
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Motion Capture
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Procedural Animation
 Generation of movement without human
oversight
 Virtual Agents
 Video Game Characters
 Can use libraries of keyframe or motion
capture animation
 Allow for dynamic or interactive environments
 Do not have the quality of previous two
methods
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Procedural Animation
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Motivation - Revisited
Hopefully, knowledge of how emotion is
expressed through nonverbal behavior can
improve interactive virtual agents to the
point where they are as engaging as
traditionally animated characters
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Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through Nonverbal
Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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Nonverbal Behavior
 Encoding
 The display of information through external
behavior
 Decoding
 The comprehension of information through
observation of external behavior
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Encoding
 Types of encoding
 [Ekman & Friesen, 1969] define three types
of coding
 Arbitrary
 No relation between coding and meaning
 Iconic
 Coding is representation of meaning
 Intrinsic
 Coding is meaning
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Complications
 Encoding may not be deliberate
 Encoding may be used to mask actual
information
 Encoding may be idiosyncratic
 Men and women encode & decode
differently
 Different cultures have different coding
rules
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Realistic vs. Believable
 Decoding research is easier than Encoding
research
 Generating Believable expressive behavior
is easier than generating Realistic
expressive behavior
 “Realistic” -> behavior as a human would
have performed it
 “Believable” -> behavior understandable by
an observer
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Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through Nonverbal
Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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Nonverbal Communication
 Technically, communication without words
 Extremely broad field [Knapp & Hall, 1997]
 Includes:
 Environment
 Appearance
 Dress, grooming
 Height, weight
 Race & gender
 None of these really express emotion
 However, they may affect appraisal ratings
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Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through
Nonverbal Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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Expression of Emotion
 What nonverbal behaviors display emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
 Expression of Emotion in Man and Animals
[Darwin, 1872].
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Posture - Demonstration
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Posture - Demonstration
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Posture - Demonstration
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Torso Posture
 Torso Posture is affected less by emphasis
and other speech-related behaviors [Bull
& Connelly, 1985]
 Positive and Negative emotions are both
easily distinguished both from static body
postures [Coulson, 2004], [Schouwstra &
Hoogstraten, 1995], and from dynamic
trunk movement [de Meijer, 1989].
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Expression of Emotion
 What nonverbal behaviors display
emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
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Head Position
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Head Position
 Movement of the head is tightly connected
to speech [Hadar et al., 1985], [McClave,
1999].
 Static posture of the head is still useful for
the display of emotions
 Head which is tilted upwards is viewed as
more dominant, and displaying a more
positive than one tilted downwards [Kappas et
al., 1994], [Mignault & Chaudhuri, 2003].
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Expression of Emotion
 What nonverbal behaviors display
emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
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Facial Expression
 Facial expression is one of the stronger
channels for emotional expression
 Paul Ekman
 Performed many of early experiments on
facial expression
 Found that facial expression was highly cross
cultural
 Developed the Facial Action Coding System
(FACS)
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Happiness
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Anger
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Sadness
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Fear
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Disgust
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Facial Expression
 Other researchers have shown that
 Children who are Deaf/Blind from birth share
many of the same facial expressions
 As do very young infants
 As well as monkeys
 [Knapp & Hall, 1997]
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Expression of Emotion
 What nonverbal behaviors display
emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
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Hand Gestures
 Much more research has been done on
the association of hand gestures with the
communication of concepts
 However, research has demonstrated that
level of arousal, and to a lesser extent the
valence of emotion can be determined
through arm movement [Pollick et al.,
2001]
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Expression of Emotion
 What nonverbal behaviors display
emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
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Gaze Behavior
 What do we mean by gaze behaviors?
 Eye shape and eyebrow position are part of
facial expression
 Length of gaze & mutual gaze
 Gaze attraction vs. aversion
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Non-Emotional Gaze
 Gaze is closely linked to speech-related
behaviors
 Patterns of gaze for individuals speaking are
often different from patterns of gaze for
listeners [Kleinke, 1986].
 Attention and Saliency also control eye
movement [Argyle & Cook, 1973].
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Gaze and Dominance
 Gaze is very important in signaling
dominance [Exline, 1971]
 However this relationship is not fully
understood
 Seen in the way monkeys perform dominance
displays when looked at by experimenters
 Highly dominant individuals look less while
listening, and more while speaking than do
individuals of low dominance [Knapp, 1997].
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Gaze and Arousal
 Gaze is also closely related to
physiological arousal [Argyle & Cook,
1973]
 Receiving gaze and engaging in mutual gaze
increases arousal
 Gaze is used as a regulation for physiological
arousal
 Increased blinks, and increased pupil dilation
are also strong signals of arousal
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Gaze and Preference
 Gaze also has a drastic effect on liking
 Individuals who gaze very little at people they
interact with are rated lower on scales of
preference, credibility, attractiveness, and are
less likely to be hired [Burgoon et al., 1985],
[Argyle & Cook, 1973].
 Individuals are also more likely to look at
people that they like [Argyle & Cook,
1973]
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Expression of Emotion
 What nonverbal behaviors display
emotion?






Torso Posture
Head Position
Facial Expression
Hand Gestures
Gaze Behavior
Movement
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Movement & Locomotion
 Emotion can be recognized through how
people walk
 But further, emotion can be recognized
through the movement of simple
geometric shapes [Rime et al., 1985]
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Movement
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Locomotion
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Synchrony
 The interactions of all of these behaviors
is as important as any single behavior
 If not, emotional signals lack coherency
 The ability of users to recognize emotion
decreases
 Believability and engagement decrease
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Conclusion – Nonverbal
 While there are many different ways
emotion can be signaled through
nonverbal behavior
 Only facial expression (and possibly prosody)
can clearly differentiate between individual
emotional categories
 Much nonverbal behavior research done using
dimensional models of emotion that can be
applied to factor analyses of nonverbal
behavior results
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Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through Nonverbal
Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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Art & Emotion
 Looking at three artistic views of
emotional expression
 Delsarte’s Structural Acting System
 Laban Movement Analysis, a system derived
from choreography
 Emotion in 2D Disney Animation
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Structural Acting System
 Francois Delsarte (1811-1871)
 French opera singer who damaged his voice
 Turned to the expression of emotion through
acting
 Compiled extremely extensive library of
movements, and the meanings of those
movements
 However, this library has not been empirically
verified
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Delsarte
 Recently, [Marsella et al., 2006] performed
an evaluation of some of Delsarte’s work
on hand gestures
 “Delsarte’s cube”
 Small imaginary cube directly in front of chest
 Placement of hands on cube sends different
signals
 i.e. hands placed on inside surface of near
face of cube to reveal possession
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Laban Movement Analysis
 Rudolph Laban (1879-1958)
 Hungarian Dancer and Choreographer
 Developed Labanotation, a notation for
recording dance
 Rendered mostly obsolete through widespread
distribution of video recording technology
 Developed, in conjunction with several of his
students, Laban Movement Analysis, a
taxonomy for describing movement
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Laban Movement Analysis
 Qualitative, hierarchical taxonomy
 Effort
 Space
 Indirect/Direct
 Time
 Sustained/Sudden
 Weight
 Light/Strong
 Flow
 Free/Bound
 Shape
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EMOTE
 [Chi et al., 2000] used Laban parameters
Effort and Shape to animate emotion
 Theory was that instead of specifying
emotional state, would instead specify LMA
parameters to animate a character
 Extended by [Zhao & Badler, 2005] which
learned LMA parameters from motion capture
or video recording
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Disney Animation
 Principles of Disney animation laid out in
[Thomas & Johnston, 1981], extended to
3D animation in [Lasseter, 1994].
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Keyframe Animation
 Skilled animators
drew key frames
 2nd Tier drew the “inbetweens”
 Developed principles
such as “Squash &
Strech”,
“Anticipation”, and
“Follow Through”
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2-D Animation
 Extremely slow process
 Highly iterative
 Highly intuitive
 Very difficult to clearly explain
 Requires great deal of training, and a certain
amount of talent
 Results are excellent
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Analyzing 2D Animation
 [Lance et al., 2004], and [Chafai et al.,
2006] were attempts to analyze 2D
animation for information on nonverbal
behavior for gaze and gesture,
respectively
 Moderately successful
 Extremely labor intensive
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Overview
 Motivation
 Psychological View of Nonverbal Behavior
 Encoding Vs. Decoding
 Nonverbal Behavior
 Expression of Emotion through Nonverbal
Behavior
 Artistic View of Emotional Expression
 Realizing Emotional Expression
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Realizing Behavior
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Animation Curves
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Animation of Behavior
 Qualitative descriptions of nonverbal
behavior need to be transformed into
quantitative changes in animation
 Two Choices:
 Directly manipulate the animation curves
yourself
 Optimization
 Develop and utilize an abstraction, such as
EMOTE or the Body Markup Language (BML)
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Conclusion
 Many sources of information for the expression
of emotion through human behavior
 Lots of them are qualitative
 Or not experimentally verified
 Or describe more subtle relationships than direct
emotional state -> behavior
 Picture is still very incomplete
 Still lots of good information for a starting point!
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References
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Argyle, M., Cook, M. Gaze and Mutual Gaze. Cambridge University Press. 1976.
Bull, P., Connelly, G. Body Movement and Emphasis in Speech. Journal of Nonverbal Behavior,
9(3). Fall 1985.
Burgoon, J., Manusov, V., Mineo, P., Hale, J. Effects of Gaze on Hiring, Credibility, Attraction and
Relational Message Interpretation. Journal of Nonverbal Behavior. 9(3). Fall 1985.
Chafai, N., Pelachaud, C., Pele, D., Breton, G. Gesture Expressivity Modulations in an ECA
Application. Proceedings of the Intelligent Virtual Agents IVA 2006 Conference. 2006.
Coulson, M. Attributing Emotion to Static Body Postures: Recognition Accuracy, Confusions, and
Viewpoint Dependence. Journal of Nonverbal Behavior. 28(2). Summer 2004.
Chi, D., Costa, M., Zhao, L., Badler, N. The EMOTE Model for Effort and Shape. Proceedings of
the 27th Annual Conference on Computer Graphics and Interactive Techniques. ACM
Press/Addison-Wesley Publishing, New York, NY. 2000.
Darwin, C., The Expression of Emotions in Man and Animals. 1872.
Ekman P., Friesen, W.V., The Repertoire of Nonverbal Behavior: Categories, Origins, Usage, and
Coding. Semiotica. 1, 49-98. 1969.
Exline, R. Visual Interaction: The Glances of Power and Preference. In Weitz, S. (ed), Nonverbal
Communication: Readings with Commentary. Oxford University Press, 1974.
Hadar, U., Steiner, T. J., Rose, F. C. Head Movement During Listening Turns in Conversation.
Journal of Nonverbal Behavior, 9(4). Winter 1985.
Kappas, A., Hess, U., Barr, C., Kleck, R. Angle of Regard: The Effect of Vertical Viewing Angle on
the Perception of Facial Expressions. Journal of Nonverbal Behavior. 18(4). Winter 1994.
Kleinke, C. Gaze and Eye Contact: A Research Review. Psychological Bulletin. v. 100, n. 1.
1986.
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References (Cont.)
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Knapp, M., Hall, J. Nonverbal Communication in Human Interaction. Fourth Edition. Harcourt
Brace Publishers. 1997.
Lance, B., Marsella, S., Koizumi, D. Towards Expressive Gaze Manner in Embodied Virtual
Agents. AAMAS Workshop on Empathic Agents. 2004.
Lasseter, J. Principles of Traditional Animation Applied to 3D Computer Animation. Computer
Graphics. v. 21, n 4. July 1987.
Marsella, S., Carnicke, S. M., Gratch, J., Okhmatovskaia, A., Rizzo, A. An Exploration of Delsarte’s
Structural Acting System. Proceedings of the Intelligent Virtual Agents IVA 2006 Conference.
2006.
McClave, E. Linguistic Functions of Head Movements in the Context of Speech. Journal of
Pragmatics. v. 32, 2000.
de Meijer, M. The Contribution of General Features of Body Movement to the Attribution of
Emotions. Journal of Nonverbal Behavior. 13(4). Winter 1989.
Mignault, A., Chaudhuri, A. The Many Faces of a Neutral Face: Head Tilt and Perception of
Dominance and Emotion. Journal of Nonverbal Behavior. 27(2). Summer 2003.
Pollick, F., Paterson, H., Bruderlin, A., Sanford, A. Perceiving Affect from Arm Movement.
Cognition. i 82, B51-B61. 2001.
Rime, B., Boulanger, B., Laubin, P., Richir, M., Stroobantst, K. The Perception of Interpersonal
Emotions Originated by Patterns of Movement. Motivation and Emotion. v. 9, n. 3. 1985.
Schouwstra, S., Hoogstraten, J. Head Position and Spinal Position as Determinants of Perceived
Emotional State. Perceptual and Motor Skills. v. 81, 1995.
Thomas, F., Johnston, O. The Illusion of Life: Disney Animation. Walt Disney Productions. 1981.
Zhao, L., Badler, N. Acquiring and Validating Motion Qualities from Live Limb Gestures.
Graphical Models. v. 67 i. 1. January, 2005.
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