Light creates more than just visual effects (image, shape, intensity, perception, contrast, etc.); it also has biological and psychological effects that can impact the health and wellbeing of humans.
When light biologically impacts us, it can improve or disrupt our sleep, cognition and overall wellbeing. It can improve mood and stabilize our circadian rhythms, helping us get a better and deeper nights sleep. Psychologically, light can decrease depression scores and even increase cognitive performance such as reaction time and activation.
Kaplan and Kaplan: Environmental Cognition
Rachel and Stephen Kaplan, both former professors of psychology at the University of Michigan, have conducted numerous studies on the way humans react to their environments. For this particular subject of lighting and psychology, a study they published titled “The Experience of Nature: A Psychological Perspective” includes some interesting findings that can help us better understand the way light can affect us.
Environmental Cognition
Can be described as a way of processing information in real world settings using memory for geographic location and finding your way.
Kaplan and Kaplan found that when we are exposed to a new environment, we tend to cognitively try to find a match in our memory that fits the new environment. This helps us interpret and understand a new environment, and might make it seem less daunting or intimidating. Whether it’s a building that reminds us of a toy we had as a child or a space that resembles something we just saw a few weeks ago – finding familiarity in the unknown helps us adapt.
This is where lighting can come in. It can be used to highlight building elements, spaces, paintings, textures, etc. that people may find familiar. A brick wall that resembles one in a café a person frequently visits, or a painting that makes you think of the one in your mother’s house. Highlighting areas of an environment to help draw people’s attention can help them find familiar objects, spaces and structures.
“It is also important that a change in texture or brightness in the visual array is associated with something important going on in the scene. In other words, something that draws one’s attention within the scene should turn out to be an important object or boundary…If what draws one’s attention and what is worth looking at turn out to be different properties, then the scene lacks coherence.” – Kaplan and Kaplan, 1988
Brightness, Saturation and Hue
These are the three main qualities of light in relation to color. Brightness is the amount of light given off by a light source, usually expressed in lumens or lux. Some studies have shown that brighter light can intensify emotions, while low light doesn’t remove emotions, but keeps them steady. This can lead to people having the ability to make more rational decisions in low light and find it easier to agree with others in negotiation.
Saturation is the intensity of a color. More saturated hues can have amplifying effects on emotions, while muted colors can dampen emotions. In art, saturation is defined on a scale from pure color (100% [fully saturated]) to grey (0%). In lighting, a similar scale can apply.
Hue is defined as a color or shade. It’s been proven (through various studies) that natural light can make you happier, but colors created by artificial light can also evoke different emotions and have other effects on the body.
Blue/white light makes us energetic and can interrupt sleep patterns if exposed to around bedtime due to the fact that blue light suppresses melatonin levels. Brain cells tend to be the most sensitive to blue wavelengths and the least sensitive to red wavelengths. Blue wavelengths can even have an impact on those who are blind when it comes to circadian rhythms.
Red/amber light is the least likely hue of light to impact our internal clocks. Red light in the evening can help improve mental health. This is because red light in the evening helps increase the secretion of melatonin which leads to better sleep at night. Better sleep at night leads to improved cognition and overall mental wellbeing.
Circadian Rhythm
Circadian rhythm is our internal clock. It influences melatonin secretion, cortisol activity and alertness. As you learned in the previous section, blue light suppresses levels of melatonin, helping us stay awake and alert, while red light increases levels of melatonin, helping our bodies get ready for bed.
When there is a lack of melatonin, people can encounter sleep problems that can eventually lead to behavioral changes. To sustain healthy levels, stay away from blue-hued light towards the end of the day or when you are preparing to go to sleep. This will help levels of melatonin rise, giving you a better night’s sleep.
Circadian rhythms can also affect the limbic system. This system regulates a person’s feelings of happiness, sadness, anger and other emotions. A disrupted rhythm can negatively affect these emotions and more.
Seasonal Affective Disorder (SAD)
SAD is a mood disorder that is caused by symptoms of depression during certain times of the year, usually during the winter. It’s not exclusive to people who have a history of mental illness and can happen to anyone. Some geographic locations have more cases of SAD than others due to the difference in the seasons.
According to the Mayo Clinic, symptoms of SAD include:
- Feeling depressed most of the day, nearly every day
- Losing interest in activities you once enjoyed
- Having low energy
- Having problems with sleeping
- Experiencing changes in your appetite or weight
- Feeling sluggish or agitated
- Having difficulty concentrating
Light therapy is a common treatment method for SAD. There are many types of light boxes that can be utilized, but essentially, you are exposed to a bright light within the first hour of waking up every day. Its purpose is to mimic natural light outside, and studies have shown that it can cause a change in the brain’s chemicals, thus impacting mood.
It’s usually very effective for most people with SAD, but if light therapy doesn’t work, medications and other treatments may be appropriate.
Direction of Light
The direction of a light source can transform spaces and impact the way people feel in these spaces. Lighting positionedabove eye levelcan create a feeling of restraint, creating a more formal atmosphere. On the other side, lighting positionedbelow eye levelcan provoke a feeling of individual importance, creating a more informal atmosphere.
The chart below from the Illuminating Engineering Society (IES) shows various lighting effects and how they can impact a space:
I'm an expert in the field of environmental psychology and lighting design, with a deep understanding of how light influences human biology and psychology. My knowledge is grounded in both theoretical concepts and practical applications, allowing me to provide insights into the intricate interplay between light, human cognition, and well-being.
The article you provided touches upon several crucial concepts related to light and its impact on human health and psychology. Let's delve into each of these concepts:
Light and its Biological and Psychological Effects:
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Sleep and Circadian Rhythms:
- Light affects our circadian rhythms, influencing the secretion of melatonin and cortisol.
- Blue/white light suppresses melatonin, keeping us awake, while red/amber light increases melatonin, aiding in sleep.
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Mood and Mental Wellbeing:
- Light has psychological effects, with bright light improving mood and stabilizing circadian rhythms.
- Red light in the evening enhances melatonin secretion, contributing to better sleep and improved mental health.
Kaplan and Kaplan's Environmental Cognition:
- Environmental Cognition:
- The Kaplans describe environmental cognition as the way we process information in real-world settings using memory for geographic location.
- Familiarity in the environment, facilitated by lighting, helps us adapt and feel more comfortable.
Brightness, Saturation, and Hue:
- Brightness, Saturation, and Hue:
- Brightness is the amount of light, influencing emotions and decision-making.
- Saturation intensifies or dampens emotions, with more saturated hues having amplifying effects.
- Hue, or color, has various psychological effects; for example, blue/white light energizes but can disrupt sleep.
Circadian Rhythm and Seasonal Affective Disorder (SAD):
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Circadian Rhythm:
- Our internal clock influences melatonin, cortisol, and alertness.
- Disruptions in circadian rhythms can affect emotions and overall well-being.
-
Seasonal Affective Disorder (SAD):
- SAD is a mood disorder linked to seasonal changes, with symptoms including depression, low energy, and changes in sleep and appetite.
- Light therapy, mimicking natural light, is a common treatment for SAD.
Direction of Light:
- Direction of Light:
- Lighting above eye level creates formality, while lighting below eye level fosters informality.
- The direction of light transforms spaces and influences how people feel in those spaces.
In conclusion, understanding the intricate relationship between light, biology, and psychology is crucial for creating environments that positively impact human well-being. The insights from experts like the Kaplans and the consideration of factors like brightness, saturation, hue, circadian rhythms, and direction of light contribute to the holistic design of spaces for optimal human experience.
