Effects of noise, heat and indoor lighting on cognitive performance and self-reported affect

Theoretical and practical concerns guided the design of an experiment on how ventilation noise (38 and 58 dBA), air temperature (21 and 27 degreesC), and illuminance (300 and 1500 lx) combine or interact in their effects on cognitive performance. Self-reports of affective states were taken with an affect circumplex measure (Larsen & Diener, 1992; Knez & Hygge, in press) to study the mediation from the environmental variables over affect to cognitive performance. Arousal models (e.g., Broadbent, 1971) would predict that increased levels of noise and illuminance increase activation and/or affect levels and that mild heat decreases it. The inverted U-bypothesis would further predict that intermediate levels of perceived arousal improve attention, memory and problem solving performance. A distinction was made between synergetic and antagonistic interactions in order to differentiate arousal and nonarousal mediated effects on cognitive performance. The results showed that attention worked faster in noise but at the cost of lesser accuracy, which supports the Speed-Accuracy-Trade-Off hypothesis (Hockey, 1984). Interactions were found between noise and heat on the long-term recall of a text, and between noise and light on the free recall of emotionally toned words. These effects on cognitive performance could not be explained as mediated by the affective states, and were not consistent with an arousal model and the inverted-U hypothesis. (C) 2001 Academic Press.