Effects of colour of light on nonvisual psychological processes

This study investigated the influence of colour of light ('warm', 'cool' an d artificial 'daylight' white lighting) on subjects' self-reported mood, co gnitive performance and room light estimation. Although no direct effect on positive and negative mood was indicated, a main effect of gender on sever al room light estimation dimensions showed that females perceived the room light, across all light settings, as more expressive than did males. Cognit ive task data revealed findings not earlier indicated by the behavioural li ghting research. Main effects of colour of light on short-term memory and p roblem solving showed that subjects performed better in the 'warm' than in the 'cool' and artificial 'daylight' white lighting. Interaction effects be tween colour of light and gender on long-term memory showed that males perf ormed best in the 'warm' and 'cool' white lighting, and that women performe d better than men in the artificial 'daylight' white lighting. All these re sults are generally in agreement with the proposition that light influences nonvisual psychological processes. (C) 2001 Academic Press.