Physio-cognitive modeling: explaining the effects of caffeine on fatigue

Most computational theories of cognition lack a representation of physiology. Understanding the effects of compounds present in the environment on cognition is important for explaining and predicting changes in cognition and behavior given exposure to toxins, pharmaceuticals, or the deprivation of critical compounds like oxygen. This research integrates physiologically-based pharmacokinetic (PBPK) model predictions with ACT-R's fatigue module to predict the effects of caffeine on fatigue. Parameter mapping between PBPK model parameters and ACT-R are informed by neurophysiological literature and established mappings between ACT-R modules and brain regions. Predicted caffeine concentrations in the brain are used to modulate a parameter in the fatigue module to explain caffeine's effects on multiple performance metrics.