SIX PAGE ANALYISE
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Lighting Influences on People’s Performance
Katherine Janney
Shijie Situ
California State University, Northridge
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Table of Contents
Introduction 3
Review of Literature 4
How the Differences in Lighting Affects Your Ability to Work 4
The Amount of Lighting Exposed in Correlation with Mood 4
Cognitive Performance Changes with Gender and Age-Based on Lighting 5
Relationship between Indoor Lighting and Mood and Cognition 6
Impact of Luminous Setting on Mood and Cognitive Performance alongside Age and Gender Lines
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The Intersection of Realistic Office Daylighting and Electric Lighting with Visual Comfort and Alertness
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Human Ecological Theory 9
Methods 11
Study of Effects of Lighting on Individuals’ Performance and Mood 11
Operationalization of Variables 11
Sample Selection 12
Analyses 12
Does Lighting Affect your Mood/Ability to Work? 13
References 16
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Introduction
As students in the interior design field, we choose this topic for several reasons but the
main one being we wanted to see the effects of lighting with an emphasis on indoor spaces
especially because we are currently in a pandemic. We all had our working environments
changed and adjusted and are on zoom calls for a lot longer and have less access to the lighting
situations. As we are not in person anymore and not on campus, we have adjusted to the lifestyle
of facing a screen for long periods of time. We both have noticed how this adjustment has
affected our performance and mood. We find it hard on our eyes, making us not as efficient as
we used to be. Our performance fluctuates a lot more often. Shijie Situ has noticed that his
performance changes in different rooms, and it is because of the lighting conditions. One room is
softer, where the other has harsher lighting. Katherine Janney finds it harder to work in a room
with harsh lighting and is easily tired after staring at a bright screen for long periods of time.
Because of this, we wanted to study how indoor lighting and daylight can affect someone’s
cognitive performance and mood in a work environment. We also wanted to compare the
different types of lighting and the effects it has on an individual. Ultimately, we want to find the
most optimal lighting condition to have in a workspace especially we are all adjusting to life
inside our homes.
While it is true that lighting can affect a person’s emotions, studies have shown that
office spaces can mitigate these problems by accounting for changes in weather patterns, changes
in the placement of the sun, and by creating lighting that is not considered poor or harsh. This
paper will investigate the different ways bad lighting can affect a person’s emotions and how
office spaces can mitigate these effects before their employees are negatively hurt because of it.
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Review of Literature
How the Differences in Lighting Affects Your Ability to Work
Lighting plays a big role in terms of working. Differences in lighting result in the altering
of the ability to work under certain lighting conditions. In a particular study, they discovered that
“photometric variables were significantly lower under overcast sky conditions than under clear
skies.” The visual acceptance score was worse in the afternoon (F 5, 105 = 4.47) and was overall
better for daylight and electric light (F 1, 21= 43.01). Electric light and daylight had equal luminous
perception scores for brightness. Non-visual assessment results “showed significant variation
over time for alertness, physical well-being and mood, such that these out-comes became worse
towards the end of the afternoon (alertness: F 5, 105 =14.8; physical well-being: F 5, 105 = 5.3; mood:
F 5, 105 = 2.6) (Borisuit, Linhart, Scartezzini, & Münch, 2014). In a study that focused on indoor
lighting, it was found that this experiment suggests that lighting can influence work performance,
but it does not make a huge difference. The illuminance had better results when it was lower. In
warm-white conditions, the 150- and 1500-lux conditions differed significantly and supposedly
made subjects feel calmer and more awake. All parts of this study offered partial support for this
hypothesis of lighting that generated positive effects (Baron, 1992).
The Amount of Lighting Exposed in Correlation with Mood
The amount of lighting in terms of brightness and even the color of the light can have a big
impact on an individual’s mood. It is possible that there could be a lot of outside factors such as
stress, depression, other mental illnesses/issues, or even outside influences that impact the mood
as well. It was found that depression was more common in the Wintertime for some of the
participants, and it was more common when they were exposed to low CS values. None of the
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correlations were significant enough and probably needed a larger sample size to see more of a
correlation between the two. Short-wavelength light plays a critical role in our biological clock.
Participants during the summertime had overall a better work ethic, had greater sleep
efficiencies, and slept more. Circadian light plays a big role in how we work in an office
environment. Seasonal lighting does play a big factor in the mood. However, in this study, they
discovered more of how light affected the psychological and physiological systems. (Figueiro, &
Rea, 2014). Lighting and mood can even differ with gender as well. An experiment found a
significant interaction between color temperature and gender when the change in mood was
tested. Females' negative mood increased in the cool and decreased in the warm, which was
inverse compared to the male reaction, (Knez, 1995). In another experiment that tested mood
within gender and age differences, they found that mood also varies across ages/gender. As a
result, for a positive mood, younger females preserved the positive mood than younger males,
but the older males preserved it better than older females. Females also preserved the negative
mood better than the males did (Knez, & Kers, 2016).
Cognitive Performance Changes with Gender and Age-Based on Lighting
As discovered with mood, there are also differences in terms of cognition performance
with gender and age in terms of lighting. Lighting has a big effect on individuals and there are
different findings on how it does so across gender and age. When participants were doing
cognitive tasks, the younger group of female and males performed better than older female and
male adults. (younger = 18.2 vs older = 6.1 out of 32). The younger participants were also better
at long-term recall and long-term recognition (Knez, & Kers, 2016). In another experiment,
males performed better than females in cognitive tasks given the color temperature. There was
also a significant interaction between motivation and color temperature, with females rating
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higher than males. In terms of the overall evaluation, the experiment "showed one significant
result that of the main effect of rate F (1, 76) = 4.13, p [is less than] .05. The male rate was
evaluated in general as significantly better in terms of performance than the female.” (Knez, &
Enmarker, 1998). Experiments on short-term recall established that women performed better
than their male counterparts. Similarly, younger adults displayed better performance in
short-term recall than senior adults. (Knez, & Kers, 2000).
Relationship between Indoor Lighting and Mood and Cognition
The correlation between lighting and psychological processes, such as cognition and
emotion, has been widely studied. Knez (1995) researched the impact of luminous setting on
mood and cognitive processes. The research adopted an experimental design, conducted in a 3.9
m X 3.8 m X 25 m chamber-room. Physical variables such as humidity and temperature and
were controlled via a computerized climate system—results from the two experiments
established that a luminous environment is a mood inducer. The luminous setting induces the
least negative mood to bolster cognitive processes such as problem-solving tasks, long-term
judgment processes, recognition, and general performance (Knez, 1995). Specifically, more
bluish and reddish lightning at high luminance induces the least negative mood, which increases
cognitive performance (Knez, 1995). The interaction between illuminance and color temperature
enhanced the performance of cognitive tasks when subjects are placed in room temperatures that
boosts the participants' mood. In nuanced experimental research, (Knez and Enmarker, 1998)
conducted the same study with a similar environmental setup. The results are discordant with the
(Knez, 1995) study, which supported the hypothesis that lighting temperature affects cognitive
performance. (Knez and Enmarker, 1998) the study affirmed (Knez, 1995) conclusive findings
that artificial lighting is a mood inducer. The addition of lighting exposure accounts for the
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diminishing. In another study investigating the interplay of illuminance, mood, and cognitive
processes, (Borisuit et al., 2014) established that participants were less alert in the afternoon
when they were subjected to daylighting than electric lighting— "(main effect of 'order'; F1, 21
1⁄4 5.38; p50.05: 2 1⁄4 0.20)." However, the study also showed that increasing vertical
illuminance could cause increase sleepiness, while comfortable lighting increased the
participants' mood, and increased their cognitive performance.
Impact of Luminous Setting on Mood and Cognitive Performance alongside Age and
Gender Lines
(Knez, 1995) narrowed the research about indoor lighting, mood, and cognitive tests on
the gender effect. Setting an experiment in a 3.9 m X 3.8 m X 25 m chamber-room, with
exaggerated décor, and a computerized climate system, the author observed varied results on the
males and the females' mood and cognitive performance. The results from the experimental
research show that there was no significant correlation between the positive mood and the
illuminance effects. However, the results projected a significant interaction between color
temperature and gender— ["F (1, 88) = 7.13, p < 0.01"] (Knez, 1995). In a similar setup, (Knez
and Enmarker, 1998) established a two-way interaction between positive mood, color
temperature, and mood ("F (1, 76) = 3.39, p = .06). Low luminous conditions generate positive
moods in males, while high luminous conditions generate positive moods in females. The warm
lighting temperature caused the females' negative mood to decrease, while the cool source caused
a negative mood to increase. Contrarily, the warm lighting source caused the males' negative
mood to increase more than than the cool white source. Experiments on cognitive performance
results demonstrated a two-way interaction between color temperature and gender. The females'
long-term memory and problem-solving performances are more bolstered in the warm white
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lighting conditions than the cool conditions (Knez, 1995). Males produced better results in low
illuminance conditions than warm lighting conditions. (Knez and Kers, 2000) experimented in a
similar milieu and found a two-way interaction between gender and age for a positive mood (F
(1, 72) = 11.76), implying that younger females exuded a positive mood than younger males (t
(38) = 1.91). The two-way interaction between gender and age was also found in cognitive
performance, with young participants performing better than the old participants in warm,
luminous conditions.
The Intersection of Realistic Office Daylighting and Electric Lighting with Visual Comfort
and Alertness
The studies on luminous temperature have made significant forays in establishing how
daylighting and electric lighting affect the productivity, health, and wellbeing of office workers.
(Borisuit et al., 2014) tested different photometric variables to establish their influence on visual
perception, comfort, mood, and alertness. The experiment was staged in a large table at the
center of the room with a large window in front. The variables were tested by exposing subjects
to electric lighting and daylighting in the afternoon as they were reading, working, and listening
to music. The impact of daylighting on the variables was studied under clear (0-25% cloud
covering), intermediate (25-75% cloud covering), and overcast sky (75-100% cloud covering)
conditions. The results show that photometric variables are lower under overcast sky conditions
than clear sky conditions. Colour co-related temperature (CCT) is high during clear skies than
during overcast skies. High CCT is associated with warm, luminous intensity, which increases
the mood and cognitive performance of individuals (Knez, 1995). Borisuit et al. 's (2014) study
also reveal that visual acceptance score, which underscores workers' comfort and wellbeing, is
generally better when employees are exposed to daylight and electric light conditions (F 1, 21=
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43.01) and worse in the afternoon (F 5, 105 = 4.47). Using ANOVA and t-tests, Borisuit et al. 's
(2014) discovered that subjective physical wellbeing, subjective alertness, and mood became
worse when employees start the day with daylighting than when they start with electric lighting
(F1, 21 1⁄4 5.38; p50.05: 2 1⁄4 0.20). However, the alertness of the subjects decreases faster when
they are exposed to electric lighting than when they are under daylighting. The results from the
study corroborate (Knez and Kers', 2000) and (Knez's, 1995) studies, which conclusively
underscore the significance of luminous intensity on the individuals' cognitive performance.
Human Ecological Theory
Lighting conditions play a significant role in an individual's well-being, mood, health,
and cognitive performance. The children's learning environment should be set up with adequate
and comfortable lighting conditions to enhance their concentration. Perhaps more importantly,
the luminous temperature of the classrooms and playgrounds should be well-managed to promote
children's cognitive and physical development. Very low or very high luminous conditions could
blight the mood of children and cause them to sleep or lose concentration during learning
sessions. When talking about the Human Ecological Theory, lighting can play a big role in each
of the parts. This theory states that individuals directly or indirectly interact with five
environmental systems, from direct contact with other individuals or institutions to outside
sources such as culture, society, and politics. Starting right the microsystem, it is important the
lighting set accordingly, so that the individual in that setting is able to work at their best ability
as well be in the best state of mind as well. This directly affects them, so having bright, warm
lighting is suggested to be the best. In the context of the mesosystem, the visual comfort of the
children's surroundings, such as home, schools, and Sunday schools, should be designed with
moderately warm lighting conditions to promote the interaction between children and parents,
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teachers, and their peers. Importantly, the working conditions should be designed to allow
comfortable electric lighting and daylighting conditions at different times of the day to facilitate
visual comfort and improve non-visual functions, such as employees' wellbeing, health, and
positive mood. When looking at the exosystem, there are a lot of indirect ways that lighting
affects an individual as well. This includes weather, however, the workplace environment
indirectly affects the psychological well-being of the children as well. The work environment has
a strong correlation with job satisfaction and work stress. A distressing work environment could
be detrimental to the parent-child relationship. In high school and colleges, conducive
photometric conditions provide a suitable environment for students to develop their memory
competence, problem-solving, and decision-making skills. Geographical locations with
comfortable electric lighting and daylighting conditions enhance the individuals' well-being by
reducing the negative mood levels and elevating the positive mood levels. When looking at both
the macrosystem and the chronosystem, poor lighting or extreme lighting conditions increase the
susceptibility of individuals to mental health conditions, such as stress, anxiety, fatigue, and
psychological distress. This can happen over time, and it is something that can not be controlled
unless it is best handled at the microsystem first. Increasing organizational productivity and
enhancing cognitive development necessitates visual comfort.
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Methods
Study of Effects of Lighting on Individuals’ Performance and Mood
In this study, we are going to research the question of whether lighting influences
people’s performance in the workplace. A stratified sample would be selected from adults within
the age range from 18 to 50. We will exclude participants who are younger than 18 or older than
50 from their answer to the first question. In the meantime, we will not restrict the sex and race
of the participants.
Operationalization of Variables
We are going to give the survey to the participants. Our demographics included in this
survey are age, sex, education, and what their degree is if applicable. We are including
education along with their degree because we want to see what kind of a workplace they would
be in. This would help us analyze what lighting conditions they would be in. This will also help
us understand the environment they are in. A high- stress environment might impact mood more
than lighting will. Lighting could also be an additional factor that impacts mood. We also had
asked for their sex because we want to compare how lighting and its impact on mood and
performance can differ between genders. Similarly, we ask for age because we want to analyze
how lighting can affect their mood and performance and whether there is a pattern of different
ages. We will be also interested in the source of light and their satisfaction level with the lighting
conditions in that environment. We will want to know whether the occurrence of light will
directly change the mood of working. Also, we will be interested in the general active time of
working for our participants. And finally, we will want to know whether the light source will
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have a direct effect on participants’ work ethics so that the participants will show a positive or
negative change in their working performances.
Sample Selection
A convenience sample will be used. Research students will distribute an online survey by
sending it to several contacts and posting it on social media platforms in hopes of getting a
variety of responses from participants of different ages and different career lifestyles. All
information will be voluntary, anonymous, and confidential.
Analyses
Quantitative and qualitative analyses will be used.
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Does Lighting Affect your Mood/Ability to Work? Introduction: We are researching how lighting affects your ability to work in a space. In this survey, we will ask some questions regarding the lighting and the effects of it. All participants will remain anonymous and confidential. Please check or fill in the appropriate response.
1. Age ______
2. Sex a. Female [ ] b. Male [ ] c. Other [ ]
3. What is the highest degree or level of education you have completed?
a. Some High School [ ] b. High School [ ] c. Bachelor's Degree [ ] d. Master's Degree [ ] e. Ph.D. or higher [ ] f. Trade School [ ] g. Other [ ]
4. What is your degree/major? ____________
5. How many hours per week do you work? (any type of work such as school, homework,
etc) _______
6. What type of lighting is provided in your workspace? Check all that apply. a. Daylight [ ] b. Fluorescent [ ] c. LED [ ] d. Other [ ]
7. Are you satisfied with the amount of lighting accessible to you when you work?
a. Very Satisfied [ ] b. Satisfied [ ] c. Dissatisfied [ ] d. Strongly Dissatisfied [ ]
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8. Do you feel that the lighting in your workspace affects your mood? a. Strongly Agree [ ] b. Agree [ ] c. Disagree [ ] d. Strongly Disagree [ ]
9. Rate your ability to work 1-4 (1 being the best, 4 being the worst) during these seasons
a. Winter ___ b. Spring ___ c. Summer ___ d. Fall ___
10. Rate your preference for these types of lighting in the workspace (1 being the best, 4
being the worst) a. Daylight ____ b. Warm Light ____ c. Cool Light ____ d. Combination ____
11. Rate your mood during these three times. ( 1 meaning you’re in the best mood, 3
meaning you’re in the worst/not the best mood) a. Morning ___ b. Afternoon ___ c. Night ___
12. Give us time in a day where you feel best motivated to work and when you feel least
motivated to work (ex: Afternoon, Night) __________________
13. Please provide a detailed explanation of your work ethic and mood and whether lighting helps it or doesn’t have an effect on it. (Ex: If you work best in daylight, provide a description of why you work best in that setting compared to an office light kind of setting).
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Thank you for taking the time to complete our survey.
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References
Baron, R. (1992). Effects of indoor lighting (illuminance and spectral distribution) on the
performance of cognitive tasks and interpersonal behaviors: The potential mediating role
of positive affect. Motivation and Emotion., 16(1) , 1–33. https://doi.org/info:doi/
Borisuit, A., Linhart, F., Scartezzini, J., & Münch, M. (2014). Effects of realistic office
daylighting and electric lighting conditions on visual comfort, alertness and mood.
Lighting Research & Technology , 47(2), 192-209.
https://doi.org/10.1177/1477153514531518.
Figueiro, MG., & Rea, MS. (2014). Office lighting and personal light exposures in two seasons:
Impact on sleep and mood. Lighting Research & Technology (London, England : 2001),
48(3), 352–364. https://doi.org/10.1177/1477153514564098
Knez, I. (1995). Effects of indoor lighting on mood and cognition. Journal of Environmental
Psychology, 15(1) , 39-51. https://doi.org/10.1016/0272-4944(95)90013-6 .
Knez, I., & Enmarker, I. (1998). Effects of office lighting on mood and cognitive performance
and a gender effect in work-related judgment. Environment and Behavior, 30(4) ,
553-567.
Knez, I., & Kers, C. (2016). Effects of indoor lighting, gender, and age on mood and cognitive
performance. Environment and Behavior, 32(6), 817–831.
https://doi.org/10.1177/0013916500326005
Knez, I., & Kers, C. (2000). Effects of indoor lighting, gender, and age on mood and cognitive
performance. Environment and Behavior, 32(6) , 817-831.
https://doi.org/10.1177/0013916500326005 .
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Veitch, J. A. (1997). Revisiting the performance and mood effects of information about lighting
and fluorescent lamp type. Journal of Environmental Psychology, 17(3) , 253–262.
https://doi.org/10.1006/jevp.1997.0059