EFFECTS OF INDOOR LIGHTING ON MOOD AND COGNITION

Two experiments investigated the effect of indoor lighting on cognitiv e performance via mood. Experiment 1 varied two lighting parameters in a factorial, between-subject design: two illuminance levels (dim; 300 lx vs bright; 1500 lx) by two colour temperatures ('warm' white; 3000 K vs 'cool' white; 4000K) at high CRI (Colour Rendering Index; 95). In experiment 2 the parameters of lighting were identical to the first e xperiment, except for the low CRI (CRI; 55). In both experiments gende r was introduced as an additional grouping factor. Results in experime nt 1 showed that a colour temperature which induced the least negative mood enhanced the performance in the long-term memory and problem-sol ving tasks, in both genders. In experiment 2, the combination of colou r temperature and illuminance that best preserved the positive mood in one gender enhanced this gender's performance in the problem-solving and free recall tasks. Thus, subjects' mood valences and their cogniti ve performances varied significantly with the genders' emotionally dif ferent reactions to the indoor lighting. This suggests, in practice, t hat the criteria for good indoor lighting may be revised, taking into account females' and males' emotional and cognitive responses as well.