Effect of Task and Eccentricity of the Target on Detection Thresholds in Mesopic Vision: Implications for Road Lighting

• Published in: Human factors Vol. 50; no. 4; pp. 712 - 721
• Main Authors: Mayeur, Anaïs, Brémond, Roland, Bastien, J.M. Christian
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.08.2008; Human Factors and Ergonomics Society
• Subjects: Adult; Applied psychology; Automobile Driving; Biological and medical sciences; Dark Adaptation - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Lighting - standards; Male; Middle Aged; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Space life sciences; Transportation. City planning; Visual Fields - physiology; Visual Perception - physiology; Human; Eccentricity; Mesopic vision; Vehicle driving; Lighting; Vision; Highway; Detection threshold; Perception; Psychophysics
• DOI: 10.1518/001872008X312260
• ISSN: 0018-7208

Objective: The aim of this work is to assess how adding a driving-related task affects the detection of objects in peripheral vision, under mesopic conditions. Background: The main index used to assess the quality of road lighting installations refers to simple detection tasks in foveal vision, which raises methodological and practical questions. Method: The experimental design consisted of a three-phase experiment. In the first phase, two groups (control and experimental) performed a peripheral detection task (simple task). Based on these results an individual detection threshold was computed for each participant and eccentricity. A tracking task was performed in Phase 2 for both groups (steering a tracking target along a circuit, on a screen). In the third phase, the control group performed the same task as in Phase 2. The experimental group performed a double task, with a tracking (primary) task and a peripheral detection (secondary) task. Results: The data show an effect of the tracking task and eccentricity on peripheral event detection. The tracking task caused detection performance to decrease from 84.2% to 67.5%, p < .001. Conclusion: The small target visibility model used in road lighting may be improved, taking into account the effects of task and eccentricity on target detection. Application: This study supports improved roadway lighting design by guiding consideration of sign eccentricity and task load.