Separated and coupled effects of illumination, accumulated noise and task complexity on cognitive-motor performance dynamics

BACKGROUND: Inconsistent findings on coupled illumination, accumulated noise and task complexity effects on cognitive-motor performance asked for a more comprehensive analysis by focusing on performance dynamics. OBJECTIVE: The aim was to investigate the effects of illumination, accumulated noise, and task complexity on several average and non-average temporal indicators. METHODS: The research was designed as a mixed factorial quasi-experiment including 83 students of transport (n = 42) and psychology (n = 41) at the University of Zagreb. Participants were assigned to designated experimental conditions defined by illumination (40, 280, 3400 lx), and accumulated noise (0% and 50% of the daily exposure limit) levels and all performed 2- and 8-choice reaction time tests. RESULTS: The findings showed negative effects of accumulated noise and task complexity on all performance indicators, while the effect of illumination reached significance only for maximal speed. Significant Illumination x Task complexity and Illumination x Accumulated noise effects were obtained for average efficiency, while significant Accumulated noise x Task complexity effect was observed for average efficiency and maximal speed. CONCLUSIONS: Various indicators of performance dynamics were diversely affected by external factors, thereby suggesting the effects’ mechanisms, and accentuating different guidelines for design of workplaces that include these environmental stressors.