Director, Office of Behavioral and Social Sciences Research What to Do With Skyler? William Riley, Ph.D. Director, Office of Behavioral and Social Sciences Research NSF International Workshop on Dynamic Modeling of Health Behavior Change and Maintenance, Sept 8-9, 2015, London, UK

Overview of Health Behavior Theories Theory – concepts, definitions, and propositions that specify the relationship among concepts for the purpose of explaining and predicting phenomena Observation Theory

Theory of Reasoned Action/Planned Behavior

Social Cognitive Theory (SCT) Dominant, influential theory of health behavior (Bandura, 1986) Lineage from Social Learning Theory Core Concepts: Triadic reciprocity (reciprocal determinism) Self-efficacy - Perceived ability to succeed in specific situations Outcomes expectancy - Perceived likelihood that performing the behavior will result in expected outcomes Cue to Action – stimulus that prompts behavior

Human-Environment Interaction is a Control System Principles of learned behavior are dynamic human-environmental interactions Pavlovian conditioning Operant conditioning Modeling Habituation Evolved so the organism can regulate the environment Human behavior is inherently a dynamic regulatory process (Riley et al., 2011)

Theory of Planned Behavior from a Control Systems Perspective Barrientos, Rivera, & Collins (2010). A dynamical model for describing behavioral interventions for weight loss and body composition change. Mathematical and Computer Modeling of Dynamical Systems. Orr, Thrush, & Plaut (2013). The Theory of Reasoned Action as parallel constraint satisfaction: Towards a dynamic computational model of health behavior. PLOS One.

What I want to know about Skyler’s food intake First, assume she’s motivated to change – entirely different if not. I want to: Be able to detect each and every time she eats or drinks, and what she eats Know environmental context (time, location, with whom, food cues) Know internal states (emotion, attitudes, food craving) And I need to learn these patterns quickly because her motivation will quickly subside if we don’t intervene quickly

JITAI for Skyler Need a model that will predict when Skyler is most likely to eat sweets, snack, etc. Need a model that will optimize the timing of the intervention based on simulated time lag from mediator being targeted to eating behavior Need a model that will optimize the intervention content to deliver – based on mediator being targeted and the relative influence of these mediators.

And Generalize from Skyler Model heavily influenced by initial states, but need to be able to compare Skyler’s behavioral influences for eating to others. Can I start with Skyler’s model and iterate on a new patient? With multiple applications of the model across individuals, can I extract generalizable vs. unique “truths” about modifying eating behavior