?The influence of light levels – and colors on human state of mind

“Beginning with man’s earliest use of controlled fire to give light to see by, lighting has been the result of the need and desire to extend the day, to supplement sun and sky, to make dark places habitable.” (Dilaura, 2006, p.1) Light has been a great asset in providing security in darkness, yet we understand very little about the biological and non-visual effects that influence a person’s state of mind and in turn well-being. Recent studies demonstrate that new discovery of novel photoreceptor cells in the eye have implicit biological effects. Related literature and research focused on vision and eye operations, circadian rhythm and light parameters such as illuminance and color temperature show correlation to a person’s state of mind. Hiroki Noguchi and Toshihiko Sakaguchi (1999) of Japan studied the “Effect of Illuminance and Color Temperature on Lowering of Physiological Activity” using electroencephalograms which measure neural activity and found significant correlation given light and color temperature. Th e purpose of this paper is to understand whether neural activity, including focus, interest, stress, engagement, excitement and relaxation given light illuminance and color temperature have any effect. Th e study results show that there is in fact relevant correlation between a person’s neural activity given light parameters on individual basis and more importantly when combining illuminance levels and correlated color temperature. With any test there are limitations and other factors that may impact the validity of the results, such as external environment factors and activities being performed by the individual.