How Light Reshapes the Mind. An Active Inference Framework for the Cognitive and Emotional Effects of Indoor Lighting

TL;DR

This paper presents an active inference framework explaining how indoor lighting influences cognition and emotion through perceptual, arousal, and behavioral pathways, supported by a formal POMDP model and simulations.

Contribution

It introduces a unified active inference model of indoor lighting effects, linking perceptual, arousal, and behavioral mechanisms in multi-user environments.

Findings

Model generates six testable predictions.

Predictions confirmed in 20 Monte Carlo simulations.

Highlights the role of lighting in shaping behavior and cognition.

Abstract

Indoor lighting affects cognition, affect, and behavioural regulation, but these effects are often treated as isolated findings rather than as parts of a unified process. This paper proposes an active inference account of shared indoor lighting in multi-user environments such as offices, classrooms, and libraries. It argues that lighting shapes behaviour through three distinct channels: illuminance modulates perceptual precision, correlated colour temperature modulates arousal relative to circadian optimum, and spectral composition biases behavioural disposition toward engagement or rest. The paper formalises this hypothesis through a proof-of-concept POMDP model of agents performing sustained reading over five hours, using both reading performance and eye-tracking observations. The model generates six falsifiable predictions, all confirmed across 20 Monte Carlo simulations.