You don't have to be a neuroscientist to understand how important light is for your daily routine. You don't have to spend your afternoons going through scientific papers to conclude that light boosts your rhythms. You can just leave the blinds open when you go to sleep and find yourself awake when the sun is out.
The effect of light on the brain has been thoroughly researched, however, light affects our brain in so many ways that scientific knowledge of brain sciences -such as it is- has yet limited information about the hardwired functions of the effect of light on humans. Light does not only (and obviously) affect our circadian rhythms and provide visual information about the world around us - it also affects our emotions.
In 1884 William James famously said that “common-sense says we lose our fortune, are sorry and weep; we meet a bear, are frightened and run; we are insulted by a rival, are angry and strike”, simplifying his theory about the effect of emotions in human behaviour and light has everything to do with emotions. The ways that humans interact with the building environment is fundamental and a key biological element in the evolution of our species. Our cities and the societies that we've built to live within them, are what Darwin would describe as key factors in the natural selection process. They are what human organisms now perceive as nature.
Here at UCL, we are deeply interested on how the building environment affect human behaviour and there are active collaborations between the Bartlett (the Centre for Advanced Spatial Analysis and the UCL Institute for Sustainable Heritage more specifically), the UCL Institute of Behavioural Neuroscience, the Department of Visual Neuroscience and UCL's neuroscience community in general. ACT Lighting Design, my non-academic but industry home, is also fundamentally interested in how lighting defines human experience and behaviour. Being a practice that our scope expands from architectural lighting design to entertainment lighting and light installations, we continuously try to improve our understanding of our profound relationship with light. To do so, we have partnered with SEAHA-CDT, a centre for doctoral training created by UCL, the University of Oxford and the University of Brighton supported by the Engineering and Physical Sciences Research Council (EPSRC) starting from museum environments and gradually expanding to other areas of application.
Light indeed affects humans in multiple and profound ways. Vandewalle from the University of Liege and his colleagues, in a paper published in PNAS (one of the most well respected scientific journal in the world) have experimented with how different spectral bandwidths activate different parts of our brain by performing fMRI on observers exposed in green and blue light. Just recently, a paper on PLOS One is even claiming that morning light helps in reducing body weight. Oxford Prof Russell Foster has also conducted pioneering research on the field experimenting with mice and humans (and has been described in his article at the Guardian).
The list is very long, however here lies the catch: scientific research on the field is not conclusive and the industry should be cautious on jumping in the hype bandwagon despite the obvious marketing merit. I believe that we, as lighting professionals, would not like to be seen as para-scientific illusionists, rather as key parts of any research on the field. Instead of blindly accepting marketing (or even scientific) trends, we should be pioneers and innovators. At UCL we are keen on working together with the industry on producing tangible research outcomes and there are a lot of opportunities (at UCL or elsewhere) for lighting manufacturers and lighting design practices and there are countless merits from such collaborations.
So, what is the circadian lighting for the lighting industry? Is it a marketing trick, just another application of LED spectrum tuning or a valid application of scientific research? None, I would argue. None yet at least. It is a great opportunity for the lighting industry to step up its pace: for the lighting manufacturers to extend the scope of their research and lighting designers to secure the importance of our role, the scientific know-how of our community.