A Ratio-and-Derivative Model of Sensory Intensity: Biological Principles of Deviation from Baseline States

This paper introduces the Ratio-and-Derivative Model of Sensory Intensity, arguing that perception arises not from absolute stimulus values but from deviations relative to baseline states, combined with their temporal derivatives. The model explains why small absolute changes can be meaningful (e.g., mosquito CO₂ detection, human photon sensitivity) and why constant stimuli fade while changes remain salient. It unifies multiple sensory modalities under the principle of ratio-based and derivative-based coding.