Understanding Decrements in Knowledge Access Resulting from Increased Fatigue

Understanding the impact of fatigue on human cognition represents an important challenge in applying research in cognitive science to real-world situations. In this study, we explored the cognitive mechanisms responsible for performance decrements in people doing the Walter Reed Serial Addition/Subtraction Task (SAST) periodically during 88 hrs of total sleep deprivation. In our model, performance on the SAST relies heavily on declarative knowledge of mathematical facts, allowing us to extend fatigue mechanisms associated with procedural knowledge from previous research to include analogous parameters and mechanisms in declarative knowledge in the Adaptive Control of ThoughtRational (ACT-R) cognitive architecture. This research contributes to a comprehensive theory of how the human arousal system impacts cognition and performance.