Because I have nothing better to post...
So seeing that I'm a bit of an uber nerdy grad student and have nothing better to blog about I've decided I'm going to start posting the annotations I'm doing for one of my classes here as well as on our class wiki. I figure this way I might, just might, get some feedback from someone about what I'm researching. The end goal of the class is to write a literature review on a topic pertaining to HCI and cognitive psychology. So the topic I've decided to look into is deriving and displaying artificial emotion in synthetic characters. This first entry is going to be three weeks worth, but from here on out it should be one week per entry. (Each week has four annotations.) Feedback and comments are more than welcome. Enjoy!
Week 1: 2006/8/28 - 2006/9/1
The Uncanny Valley Mori, Masahiro. "The Uncanny Valley." Energy 7(4) (1970): 33-5. Trans. Karl F. MacDorman and Takashi Minato.
In this article Mori discusses his hypothesis about how as robots become more human in appearance they also become more familiar to humans. But this only occurs up until a certain point at which the likeness is almost human but not quite and the familiarity drops off drastically and becomes negative. Mori calls this the uncanny valley. When movement is added to the robot the distinction of positive and negative familiarity becomes even more defined. He helps explain this with a graph of two peaks with a valley in between; the peaks representing high familiarity and the valley representing the “uncanny valley”, strange and unfamiliar, as something gains a more human likeness. Mori suggests that as robots are designed that we don't shoot for the second peak (the most human-like) but for the first peak. Establish a familiarity but avoid falling into the uncanny valley.
Androids as an Experimental Apparatus: Why Is There an Uncanny Valley and Can We Exploit It?
MacDorman, Karl F. "Androids as an Experimental Apparatus: Why Is There an Uncanny Valley and Can We Exploit It?" Cognitive Science Society (2005).
This article talks about how androids, specifically very human looking androids, can elicit a subconscious fear of death. MacDorman explains a experiment he conducted. He uses terror management theory and mortality salience hypothesis as theories as to why uncanny androids will provoke fear of death. He showed two groups a set pictures, one set including an image of a human woman looking android (experimental), the other with an image of an Asian woman (control) and then asked them a series of world view questions and word completion problems. The results obtained were inconclusive largely because lack of statistical deviation between the two groups. MacDorman then conducted interviews through instant message with some of the participants after the questionnaire was concluded. He claims that the interviews show more conclusively that the picture of the android creates a subconscious fear of death. It should be noted though that the questions asked were leading.
Synthetic Social Interactions
Romano, Daniela M. "Synthetic Social Interactions." Proc. of Human-Animated Characters Interaction, 2005, Edinburgh. Edinburgh: Napier University, 2005.
Romano discusses the different aspects of what would make a virtual character intriguing to people. These synthetic social interactions are becoming more mainstream with the use of interactive avatars on websites that help direct users. The key things she points out that make these characters believable, and evoke an emotional response, are the ability to process and respond to text or speech input, and their ability to display a range of emotions and personality traits through their face and body movements. To elicit these behaviors she poses different personality models such as the five factor model (FFM), Ortony, Clore and Collins (OCC) model. She also indicates that for the avatar to be truly believable it also needs to posses some sort of social cognition.
Virtual people: capturing human models to populate virtual worlds
Hilton, Adrian, et al. "Virtual people: capturing human models to populate virtual worlds." Proc. of Computer Animation, 1999, Geneva.
This article describes a technique for 3D human model reconstruction. It is designed to be a low-cost and automatic process for use in different types of virtual environments. To summarize, four photographs of a person are taken in front of a blue screen: front, back, left and right. These photos are then analyzed by an algorithm that determines how a predefined human model should be modified to represent the person in the photographs. Texture maps are also created from the photos and applied to the model, and the joint positions are moved to allow for more accurate kinematics. The current limitations of their work are also discussed briefly. For instance, they currently lack facial feature point labeling and precise kinematic structure reconstruction. In the future this might be a better way of creating human models with out falling into the uncanny valley.
Week 2: 2006/9/4 - 2006/9/8
On making believable emotional agents believable Ortony, Andrew. "On making believable emotional agents believable." In Trapple, R., P. Petta, Emotions in humans and artifacts. Cambridge: MIT Press, 2003.
In 1988, Ortony, Clore and Collins developed a framework with 22 emotional categories, known as the OCC model, for developing believable emotional agents. In this article Ortony discusses possible adaptations to this model to make it simpler and more accurate. He proposes to reduce the number of emotional categories to five positive and five negative categories. These create a consistency in the agent by evoking similar emotions in similar situations. He then discusses the intensity of the emotion that is expressed in three types of emotion response tendencies: expressive, information-processing, and coping. These things create a personality for what hopefully will be a believable agent. Something lacking is a history, or memory. The agent will react with the same intensity to a particular situation the same way it did a few moments earlier, and will continue to react the same way no matter the frequency of the situation. I think this is something Ortony fails to address in his discussion of intensity.
Integrating the OCC Model of Emotions in Embodied Characters
Bartneck, Christoph. "Integrating the OCC Model of Emotions in Embodied Characters." Proc. of Virtual Conversational Characters: Applications, Methods, and Research Challenges, 2002, Melbourne.
In this article Bartneck discusses the OCC model and applying it to agents. He lists five phases the agent uses to process an event: classification, quantification, interaction, mapping and expression. In the classification phase the agent determines whether the event is good or bad. To do this, Bartneck says it needs knowledge of its world, including standards, goals and expectations. The quantification phase determines the intensity of the emotion displayed by the agent. Here is where Bartneck finds fault in the OCC model and recognizes that the agent needs a history function that keeps track of past events that allows for recalculation of emotion. The third phase, interaction, isn't described in the OCC model either. This phase determines how the current event and it's emotional response will interact with the current emotions the agent has. During the mapping phase the emotional response is mapped to one of the OCC emotion categories. Finally, in the expression phase the determined response is expressed through the available means. Bartneck's conclusions are that the OCC model is a good starting place for developing a believable agent, but history and emotion interaction functions need to be integrated into this model for them to be more effective.
The Five-Factor Mode: Emergence of a Taxonomic Model for Personality Psychology
Popkins, Nathan C. "The Five-Factor Mode: Emergence of a Taxonomic Model for Personality Psychology." 1998. Personlaity Researcy. 1 Sept. 2006
Popkins evaluates the five-factor model based on compatibility, taxonomy, application, originality and universality to test its theory potential. He starts by first describing the five-factor model (FFM) of personality. These five factors are extroversion-introversion, neuroticism, agreeableness, conscientiousness and openness. Popkins conclusions and arguments are somewhat contradictory. It is compatible with other factor-models based on the fact that it stems from Cattell's sixteen-factor model much like the PEN model does. It is quantifiable and categorical but leaves something to be desired in many situations do to its broad overview. On one hand he cites McAdams stating that “Personality theories do more than specify traits” causing FFM to not really be a valid theory, but at the same time also saying that it can be used effectively in application, specifically in academia. Popkins then goes on to claim that FFM is an original model, even though he stated earlier that it stems from the sixteen-factor model. He justifies this by stating that these are a family of models and they exist autonomously from other major psychological theories. For it to be universal it should be able to be applicable cross-culturally and in any situation, but as he previously stated, and does so again, FFM doesn't anticipate behavior, though he states that it does well cross-culturally. He finally concludes that FFM is more a taxonomy than a theory.
The Uncanny Valley: does it exist?
Brenton, Harry, et. al. "The Uncanny Valley: does it exist?" Proc. of Human-Animated Characters Interaction, 2005, Edinburgh. Edinburgh: Napier University, 2005.
Brenton et al. discuss the existence of the Uncanny Valley as described by Mori. Currently there has been little research into this topic as to whether it is something quantifiable. Their goal is to develop hypotheses that will provoke later research and help determine if the uncanny response is measurable. Brenton et al. present a series of four hypotheses to further investigate the uncanny response. Measurement of presence in the uncanny using a theory presented by Slater. Perceptual cues and realism suggest a character is a person, and in highly graphical realistic characters when behavior and motion don’t match with graphical representation can be unsettling. This is especially noticeable in their third hypothesis pertaining to perceptual cues in the eyes and face of a character. Their last hypothesis looks into how the uncanny can be perceived differently over a period of time, and across different cultures. These hypotheses will help to further investigate the Uncanny Valley and to determine if the uncanny can be measured experimentally.
Week 3: 2006/9/11 - 2006/9/15
The Art and Science of Syntehtic Character Design Kline, Christopher, and Bruce Blumberg. "The Art and Science of Syntehtic Character Design." Proc. of AISB Symposium on AI and Creativity in Entertainment and Visual Art, 1999, Edinburgh.
This article discusses the creation of synthetic characters. The elements Kline and Blumberg see as key to making a believable character, what we expect from them, are motivational drive, emotion, perception and action selection. To implement these subsystems they have devised a framework that encompasses all of them instead of focusing on each individually. The framework is value-based, meaning input is given a numeric value which can then be evaluated to derive the action the character should take. The sensor primitive is the character's input device. It takes the world and other sensors output as input. The transducer primitive takes the sensor data and begins calculating it. The data then moves to the accumulator primitive where it is computed and then sent to a semantic group that applies a behavior. Kline and Blumberg also give examples of how this value-based framework can be applied to each of their subsystems. The interesting part of this framework is it takes into account all inputs/outputs the character is receiving and has the potential of prioritizing them as well as keeping a sort of history as to what has already happened.
Modeling Emotions and Other Motivations in Synthetic Agents
Velásquez, Juan D. “Modeling Emotions and Other Motivations in Synthetic Agents.” Proc. of the AAAI Conference, 1997, Providence.
Velásquez discusses the Cathexis model which is a “... distributed model for the generation of emotions and their influence in the behavior of autonomous agents.” and takes into account the emotions, moods, temperaments. He has opted to group emotions in to specific emotion families and represent them with proto-specialists, which are comparable to Minsky's. They are comprised of four sensor groups and contain activation and saturation of emotion thresholds, duration of emotion, intensity of emotion, and also contain an emotion decay function. Emotion proto-specialists can also run in parallel, meaning more than one can run at a time. Velásquez also differentiates between moods and emotions, moods being low levels of arousal while emotions consist of high levels. He also briefly discusses the behavior system which is a network of behaviors that decides what behavior is appropriate given the current emotional state. The Cathexis model incorporates different aspects of other models to create a more encompassing and dynamic model for creating synthetic characters. Velásquez also recognizes the lack of memory and learning, and other influences of emotions on behavior.
Artificial Emotion: Simulating Mood and Personality
Wilson, Ian. "Artificial Emotion: Simulating Mood and Personality." Gamasutra 7 May 1999. 15 Sept. 2006
Emotion in characters is key to creating a believable environment. Wilson describes personality in three layers of emotion. The top layer consists of momentary emotions, behaviors that are briefly displayed in response to events. The middle layer consists of moods, which have a cumulative effect and are more prolonged. The final layer is personality that is more stable and is expressed when no momentary emotion or mood supersedes. Other important points Wilson brings up are how emotions serve social functions, making characters we encounter engaging. And he brings emphasis to actions and gestures, meaning hand, body and facial movements. These movements add a lot to characters emotions and personalities making us want to find out more about them, why they are moving the way they are.
Emotionally Expressive Agents
Seif El-Nasr, Mary, et. al. "Emotionally Expressive Agents." Proc. of Computer Animation, 1999, Geneva. pp. 48-57.
Fuzzy Logic Adaptive Model of Emotions, or FLAME, produces smooth transitions between emotions by relating events, goals and emotions, while also incorporating learning algorithms. Seif El-Nasr et. al. define three components of the FLAME model: emotion, decision-making, and learning. The emotion component applies goals and expectations to an event. Using a model similar to the OCC model , the event is appraised and a behavior is selected. This behavior is passed to the decision-making component where a decay function is applied to it and it is acted out. So far this is much like Velásquez’s model. But here is where it begins to deviate and expand. Seif El-Nasr et. al. implement a learning algorithm which logs observed sequences of events, or patterns, of length x. Each time the sequence is observed a count is incremented and the probability of a new event occurring given previous events can be calculated. They also implement reinforcement learning where after a series of experiences the agent will be able to associate an event with a goal and will perform the rewarding action.
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