Why the change of heart? Understanding the interactions between physiology, affect, and cognition and their effects on decision-making

Open Access
Dancy, Christopher Lee
Graduate Program:
Information Sciences and Technology
Doctor of Philosophy
Document Type:
Date of Defense:
March 17, 2014
Committee Members:
  • Frank Edward Ritter, Dissertation Advisor
  • Frank Edward Ritter, Committee Chair
  • Michael Mc Neese, Committee Chair
  • John Yen, Committee Member
  • Frank Gerard Hillary, Special Member
  • Cogntion
  • Affect
  • Emotion
  • Physiology
  • Computational Model
  • Process Model
  • ACT-R
  • HumMod
  • Iowa Gambling Task
  • Decision-Making
How do physiological and affective processes interact with cognitive processes to change the way we think? How can we better understand the processes that underlie decision-making and choice behavior? This dissertation presents a novel hybrid cognitive architecture, ACT-R/Φ, which extends the ACT-R cognitive architecture with an integrative model of physiology and a model of affect and emotion. Extending a cognitive architecture with representations of affect and physiology allows the straightforward development of more illustrative computational process models of human behavior that explain experimental results from physiology, neuroscience, and psychology. Computational models were developed that provide an account of how physiological change due to psychological stress or homeostasis can modulate cognitive processes. An experiment was also run to explore how subliminal visual emotional stimuli affect physiology and decision-making behavior during the Iowa Gambling Task. Results indicate that effects of subliminal affective stimuli were dependent on participant sex and personality differences. A computational process model was developed that performs the same task and behaves similarly to the participants. Physiological and affective states continually interact with cognitive processes, biasing memory and, consequently, decisions. Evolved adaptations that support physiological and affective change of behavior (e.g., natural reactions to thirst or hunger) affect the way we learn and make choices. The ACT-R/Φ hybrid architecture, and the theoretical architectural models that define it, can be used to develop models of human behavior that include the necessary accounts of physiology and affect that describe what the body needs and how changes in behavior affects these needs. This improved understanding of the architecture that constrains our behavior gives us a better opportunity to comprehend why we make the decisions we do and how we can use this knowledge to make better decisions.