The lack of light is usually thought to affect the mood: it can lead to the condition known as seasonal affective disorder, or winter depression. However, recent studies by North American researchers show that both positive and negative emotions may be intensified by brighter lighting, while lower lighting may dampen those moods. Contrary to popular belief these researches show that depression-prone people actually become more depressed on sunny days.
Other similar correlation measures the effects of different colors of light on human’s mood and behaviour and how these can affect the body in different ways.
Researchers at the University of Liege have measured the impact on the brain of alternating blue and green lights and shown that blue light stimulate and strengthen connections between brain areas involved in the process of emotions and language. Blue light improves alertness and mental performance and seems to primarily affect the mind, including mood. Neurologist George Brainard explained that after thousands of generations being hunter-gatherers, out in the daylight and exposed to the blue sky, we’ve become [a] predominantly indoor-dwelling species.
Researchers investigate how precisely lighting can affect social interaction and communication, mood, health, satisfaction and comfort and try to clarify lighting effects on hospitals, stores, etc. These correlations have practical applications in healthcare and hospitals, where lighting is increasingly taken into account to improve the well-being of patients, reduce stress and anxiety related to hospital environment. The light therapy that uses some colors like blue sky effects is also used to relieve the stress generated by some protocols like X-ray or scanner by providing a fun and comforting environment for children.
Appropriate lighting in classrooms plays a key role to promote the visual comfort of students by facilitating their learning and concentration.
These correlations also have applications in the marketing field in order to influence consumer behaviour. Shops selling emotionally expressive products, such as jewels and engagement rings will emphasize high illumination level playing on the intensity of light to increase the intensity of the emotion.
Belgian researcher Gilles Vandewalle suggested that we could think about changing the lighting in our homes and offices and introducing blue-enriched light, pointing to previous studies that found that people feel better, perform better, and sleep better when working under blue-enriched light.