Seven Layers of Physiological State: A Multilayer Architecture for Understanding State-Dependent Accessibility and Behavior

The Nonlinear Physiology–Behavior Equation identifies physiological state (P) as a central organizing component contributing to state-dependent variability in human functioning. Although this equation establishes the importance of the physiological state, its internal organization remains unclear. This manuscript addresses this question by proposing the Seven Layers of Physiological State™, which conceptualizes the physiological state as composed of seven layers: the Environmental–Physiology Interface Layer, Sensory Processing Layer, Autonomic Layer, Interoceptive Layer, Hormonal–Neuroendocrine Layer, Affective/Emotional-State Layer, and Cognitive–Regulation Layer. State-dependent variability emerges through ongoing interactions among these distinct but interconnected layers. A central proposition of this framework is that accessibility is an emergent property of physiological organization. Communication accessibility, emotional accessibility, cognitive accessibility, executive accessibility, relational accessibility, and behavioral accessibility are proposed to vary as the physiological state changes across time and conditions. Variability in behavioral expression may reflect differences in the accessibility of adaptive capacities, despite the continued availability of underlying adaptive repertoires. The framework also describes how bidirectional influences, cross-layer interactions, cascading effects, adaptive reorganization, state transitions, and Nonlinear dynamics may contribute to variability in accessibility, regulation, adaptation, learning, and behavioral expression. Although empirical investigation is needed, the proposed architecture offers a conceptual foundation for future research examining the organization of physiological state and its relationship to state-dependent variability, providing a basis for future measurement development, accessibility assessment, observational methodologies, longitudinal investigation, and cross-disciplinary applications.