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.
Human-Centric Lighting (HCL)
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.
Adding color to the lighting mix
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.
Related links
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