Eye Movements: Measuring Fatigue and Attention in Natural and Urban Scenes

Abstract

Exposure to nature can improve affective and cognitive states, reducing stress and arousal. Across four experiments, I measured eye movements when viewing natural and urban environments in the laboratory, recording changes in visual exploration and fatigue. My dissertation formally investigates the relationship between affective preference and visual exploration. For the first time, I gathered data from microsaccades to measure changes in fatigue and arousal while people view natural and urban environments. Natural scenes involved longer and more frequent fixations than urban scenes. I measured blink rates and microsaccade slopes as eye movement indicators associated with arousal and fatigue. These measures indicated that viewing natural scenes involved lower arousal than urban scenes. For static natural and urban scenes, preference was associated with increased fixation count. In experiment 2, I found that fractal complexity influences visual exploration and preference. More complex scenes elicited shorter saccades and were more pleasant, especially for urban scenes. In experiment 3, I contrasted different types of natural and urban environments. I showed that historic architecture was preferred to modern architecture, and that it involved lower fatigue and more exploratory eye movements. In experiment 4, I showed that differences in visual exploration and arousal between natural and urban scenes remained significant when using video stimuli, and when depleting attention beforehand using a sustained attention task. As eye-tracking grows in popularity for measuring experiences in architectural and natural environments, these experiments provide a valuable resource for understanding the relationship between eye movements, affective processing, and fatigue.