I’ve been thinking about the connection between the color of light in a room and how we feel. What got me started on this was a session I attended, at the US Department of Energy’s Better Buildings Summit, hosted by Dr. Steven Lockley, of Harvard University and Dr. Lori Brock, of Osram Lighting.
Dr. Lockley is an associate professor of medicine at Harvard Medical School, and an associate neuroscientist, in the area of sleep medicine, at Brigham and Women’s Hospital in Boston. He’s measured how the human body reacts to color stimulation, and has published his conclusions in multiple research papers.
In Dr. Lockley’s session, I learned that how we respond to lighting is one part biology and one part physics, since our bodies react to the particular energy associated with a given color. Red lighting, for example, puts us to sleep. In nature, the human eye is conditioned to respond to red, in the form of sunsets and firelight, as a signal that the day is done. Our bodies respond to red light with a chemical reaction, involving the release of melatonin and we get sleepy. Blue lighting, on the other hand, is the color of early morning, as the sun rises, and our bodies react to it by waking us up and making us more alert.
Dr. Lockley described a study he’d conducted with Dr. Brock and Osram Lighting, in Germany. The study used two identical classrooms, except one had normal “warm-white” lighting, which has a high red component, and the other had “cool-white” lighting, which has more blue. After several months, the students swapped classrooms. At the end of the study, the number-one complaint from students was that they found it impossible to sleep during “boring” classes when they were in the classroom that used the cool-white (blue) lighting. Dr. Lockley has even found that exposure to blue light is more effective than caffeine as a stimulant. A few minutes of exposure to high-intensity blue lighting leads to hours of increased alertness.
I spoke to Dr. Lockley after his presentation, and told him about an experience I’d had flying cross-country. I hadn’t been able to nap because the overhead lights were blue. Dr. Lockley said he’d heard this before, and had contacted airplane manufacturers and airlines to tell them about the stimulating effects of blue lighting. He finds that many people think blue is a “calming” color in lighting when, in fact, it’s the opposite.
Using some of the concepts explored by Dr. Lockley, I can create different lighting effects at home, depending on how I want to feel. RGB LEDs, which use red, green and blue lights to produce a broad array of colors, are the starting point. When connected to a network, the lights can be programmed for different situations and can respond to things like the time of day or changes in the weather. As bedtime approaches, for example, the lights can take on a red hue, to help me relax. Or, if it’s grey and cloudy out, the lights can use the blue spectrum to brighten my outlook and give me a mental boost. Either way, I’ll be using what can truly be called “mood lighting” to increase my wellness and improve my state of mind.
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Roman Budek has been working with wireless technologies for more than 10 years. At NXP, he looks at ways of using wireless to enhance smart energy, consumer, and lighting applications. He has a BSEE form the University of Illinois at Urbana-Champaign.
