Emotion as a Layered Control System Nancy Alvarado

What Does Emotion Do for Humans? It is part of what it means to be human. It makes life “worth living” by giving value to experiences. It permits us to respond flexibly to our environment, avoiding bad, approaching good. It coordinates brain, body & behavioral responses. It guides inter-personal relationships. Emotion is necessary to cognitive development because adult-child interaction is facilitated (Kismet).

Emotion & Consciousness Emotion is not strictly a phenomenon of consciousness, although its self-report is. Implicit vs explicit emotions Effects on motivation, memory, decision, other cognition can be set aside when emotion is consciously experienced. Moods vs emotions Long-lasting vs short duration Non-conscious vs conscious Unattributed vs attributed cause

Access vs Phenomenal Consciousness Without phenomenal consciousness, emotion has no effectiveness as a motivator of human behavior. We can prove that phenomenal consciousness exists by observing its impact on behavior. Access consciousness appears to be optional. But perceptual accounts focus mostly on access consciousness not phenomenal. Emotion works the opposite way.

Computer Functions of Emotion Coordinate internal system-wide responses to an environmental stimulus. Bias values of parameters. Identify goal-relevant outcomes and flexibly select responses to them. Prioritize among competing processes. Evaluate and communicate internal states to users.

Affect-Guided Cognition Barnes & Thagard’s DECO system – emotion-guided decision making An affective version of Newell’s SOAR architecture, used in military simulations – Jones, Chown & Henninger Moffat & Frijda – WILL, personality-based autonomous agents Kismet’s behavioral choice system

Sloman’s Distinction Shallow implementations: Behaviors that simulate affect Simple links between triggers and behaviors Use of emotion term labels for variables Deeper implementations Emotion is an integral part of a theory of mind Emotion influences cognition at multiple levels Guided by functionality

Zombies (Robots) Some claim that it is the ability to feel emotion that makes us uniquely human. Rodney Brooks, representationalist, disagrees:

Kismet Cynthia Breazeal (MIT) and her sociable robot – affect motivates and guides social learning. Breazeal, C. (2002). Designing Sociable Machines, MIT Press

Joshua Blue (IBM) Goal – to develop common sense reasoning and human-style semantic processing in a computer system. Method – permit an embodied system with sensors and effectors to develop its own meaning-system through experience in a rich environment. This is what people do.

How Does Joshua Work? Joshua is a deep implementation, using Sloman’s terms. Emotion (valence/arousal) is embedded and affects every aspect of processing. Top-down effects come from cognitive modules operating upon nodes in the semantic network. Joshua has facial expressions to facilitate social interaction and external regulation.

Implementation A spreading-activation semantic network with an advanced knowledge representation creates associations based on experience. Links that are used gain strength, unused links are pruned, as with neurons. Links that rise above a threshold are considered to enter consciousness and become the focus of a set of higher-level cognitive processes.

Emotion is Crucial Every node has an emotional valence assigned when it is created, based on the system’s overall emotional state. The system-wide state constantly changes to reflect the states of the individual nodes. A second parameter, arousal, also determines the strength of valence and the spreading activation among nodes. Consciousness threshold varies with arousal.

Layered Control Emotion performs different functions at different levels in the system: Valence & arousal bias which nodes become active and rise to the consciousness threshold. Appraisals of experience can also change emotion, results of cognition affect emotion. In consciousness, meaning is assigned to certain emotional states – a perceptual approach, permitting override of emotion. External influence comes from social interaction.

Some Shallow Implementations Limited emotional functionality has been designed into a variety of systems with special purposes. Few theorists have focused on emotion in the architecture of mind, but there exist many models of specific aspects of emotion: Appraisal theory Basic emotions theory Approach/avoidance models

MIT Learning Companion Pupil Detection Using the IBM BlueEyes Camera Kapoor, Mota & Picard (2001). Towards a Learning Companion that Recognizes Affect, AAAI Fall Symposium 2001, North Falmouth, MA

Relational Agents Tim Bickmore has developed a virtual agent that acts as an exercise coach to encourage physical training. Here he is shown talking with Rea, a virtual real estate agent.

Sensing Driver Affect Detecting Driver Stress – MIT Media Lab Healey & Picard (2000). Smart Car: Detecting Driver Stress. Proceedings of the 15th International Conference on Pattern Recognition, Barcelona, Spain.

CMU’s OZ Project (Bates/Reilly) Otto & Iris are animated characters that express their own feelings in interactive games Zoesis Studios,

Robot Improv “ Two robots perform a short play based on an elementary acting exercise … The actors decide on their next action and line of dialog based on their current goals and emotional state and the other actor's last actions. There is no pre-determined script, only sets of available actions and dialog for the actors to choose from. Each play is improvised at run-time. ” Bruce, Knight & Nourbakhsh. Robot Improv: Using Drama to Create Believable Agents. The Robotics Institute, Carnegie Mellon University

Navigating Environments Rodrigo Ventura and colleagues have created soccer-playing robots that learn to respond to environmental cues Sadio, Tavares, Ventura & Custodio (2001). An emotion-based agent architecture application with real robots. AAAI Fall Symposium, N. Falmouth, MA.