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Volume 26, Issue 1 (Spring 2024)
Advances in Cognitive Sciences 2024, 26(1): 46-62 |
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Soltanzadeh S, Chitsaz S, Kazemi R. Investigating the effect of color and lighting of the workspace on the mental workload and sustained attention of employees: A study in virtual reality. Advances in Cognitive Sciences 2024; 26 (1) :46-62
URL: http://icssjournal.ir/article-1-1647-en.html
URL: http://icssjournal.ir/article-1-1647-en.html
1- PhD Student, Department of Social Cognition, Institute for Cognitive Science Studies, Tehran, Iran
2- Assistant Professor, Institute for Cognitive Science Studies, Tehran, Iran
3- Assistant Professor, Faculty of Entrepreneurship, University of Tehran, Tehran, Iran
2- Assistant Professor, Institute for Cognitive Science Studies, Tehran, Iran
3- Assistant Professor, Faculty of Entrepreneurship, University of Tehran, Tehran, Iran
Abstract: (1487 Views)
Introduction
There is no doubt that indoor environmental quality is crucial to the health and well-being of its inhabitants. It is crucial to determine the impact of these parameters on human perception to improve building design standards. Color and light are environmental factors that affect cognitive functions. Numerous studies have examined the role of lighting, demonstrating that physical environments can be designed to impact the visual, psychological, physiological, and cognitive performance of their inhabitants. The science of cognitive ergonomics is concerned with studying mental processes, including perception, memory, mental workload, inhibition, attention, interactions between humans, and systems to ensure the correct interaction between work and environment, needs, capabilities, and limitations. Therefore, paying attention to the design factors in the work environment to improve cognitive functions requires the interdisciplinary cooperation of psychologists, designers, and architects.
A comprehensive approach requires investigating and identifying potential objective and subjective measures of the work environment to improve cognitive functions in the workplace. Due to the importance of this cognitive function in different dimensions of life, the subject studied in many researches is focused on sustained attention. In addition, the studies show that cognitive functions, as well as mental health indicators are related to indoor environment parameters such as light. This study aimed to investigate the combined role of lighting intensity and color on mental workload and sustained attention in the work environment.
Methods
This research, is a clinical trial study with a quantitative approach aimed at developmental and applied purposes. The participants for this study were selected through a voluntary, non-random method based on specific entry and exit criteria following an open call for research on social networks. The Continuous Performance Test (CPT) continuous performance test was introduced in 1956 by Rosold et al. This test is used to evaluate sustained attention and impulsive movements. The task was designed to move the boxes on the conveyor belt in front of the participants, simulating the virtual environment with the actual work environment. Single-digit numbers from “0 to 9” are written on each of these boxes. The participants were required to identify the boxes with the target stimulus, considered the number “0” in this study. The NASA workload index test has been used in many studies to evaluate mental workload. This test has been used to evaluate mental workload in six subscales. The use of virtual reality as a research tool is well-established in many fields, including cognitive research. Moreover, virtual reality has a strong potential to be used as an experimental research tool in psychological and architectural research. The simulated environment in this research is a high dynamic range image model HDRI. The simulated workspace is a windowless room with artificial lighting. The color of the walls based was selected on the levels of the variables. Electroencephalography data was recorded with the help of a Q5000 EEG device (Negar Andishgan Co., Iran). This study used Ag/AgCl electrodes to record electroencephalography signals installed on an elastic cap. Thirty-two electrodes based on the international 10-20 system were installed on the participants’ heads.
At first, the experiment process was fully explained to all the participants, and the participants completed the informed consent form and the demographic information questionnaire. First, electroencephalography was recorded for 2 minutes with eyes closed before the virtual reality glasses were placed on the head. In the next step, people were asked to put on virtual reality glasses. The experiment was conducted randomly, and people encountered each of the four scenarios designed in the virtual reality environment with a wall color while their brain waves were recorded. The experiment duration for each participant was 3 hours, with steps for preparation for the electroencephalography recording.
Results
CPT task was performed to assess the significance of changes in dependent variables (accuracy, attention, inhibition, and reaction time) in different situations (four situations) of multivariate covariance analysis. Box’s M test was performed to check the equality of variance-covariance matrices to check the assumptions of multivariate covariance analysis, and this assumption was confirmed with the obtained results (F(30, 36)=2.736, P=0.005). Multivariate covariance analysis showed a significant difference in at least one of the dependent variables (F(12, 105)=2.244, P<0.05), Eta=0.20. The results of Scheffe’s test show that placing subjects in different positions significantly affect “accuracy” (F(3, 36)=9.719, P<0.05, Eta=0.44), attention (F (3, 36)=5.206, P=0.004, Eta=0.30) and inhibition (F (3, 36)=5.018, P=0.005, Eta=0.29), But there was no significant change in "reaction time" F(3, 36)=151.6, P>0.05, Eta=0.11). Scheffe’s post hoc test results showed a significant difference between the "accuracy" performance of individuals between positions 1 and 3 (P=0.003), 1 and 4 (P=0.001), 2 and 4 (P=0.21), 3 and 1 (P=0.003), 4 and 1 (P=0.001) and 4 and 2 (P<0.05), a significant difference between people’s “attention” performance between positions 1 and 3 (P=0.031), 1 and 3 (P=0.031) and a significant difference in "inhibition" in environment 1 and 3 (P=0.04), environment 2 and 3 (P=0.04) and environment 3 and 1 (P=0.04) showed.
Examining the average scores of NASA’s workload questionnaire showed that the lowest score was in the condition with a white wall and 800 Lux lighting. Furthermore, the analysis of the data in the ANOVA statistical test indicated no significant difference in the workload imposed on the individual in different situations (P<0.05) and no interaction effect between environment design and workload.
The pairwise comparison test revealed a significant discrepancy in the measured values of the normalized brain signal strength measured when each participant rested and performed the task in the four studied positions in virtual reality.
Conclusion
The present study aimed to investigate the combined role of two components of lighting intensity and color in the work environment with sustained attention and mental workload. The results showed that the interactive effect of color and light, with the combination of white and blue colors and light intensity of 300 or 800 Lux, on mental workload insignificant. This means that the design interventions resulting from the combination of these two variables did not significantly affect the scores obtained from the NASA questionnaire.
In the present study, the one-way analysis of variance of the absolute power of the frequency bands shows that when the brightness intensity increases, it does not create a significant difference in people’s attention in the electroencephalogram data. Similar to accuracy performance, inhibition performance also improves under the influence of design interventions in color and illuminance intensity. This finding can be explained using the principles of Kaplan’s theory of attention recovery and psychological recovery. Attention recovery theory emphasizes that the presence of natural elements plays a role in reducing anxiety and mental fatigue in people.
Recent studies show that the color blue can boost employees’ attention and cognitive functions. By incorporating blue into office design, organizations can enhance cognitive abilities, work performance, and overall productivity.
Ethical Consideration
Compliance with ethical guideline
This research was carried out in compliance with ethical principles, including obtaining written informed consent, the principle of confidentiality, providing sufficient information about how to conduct the research, and the freedom of the participants to withdraw from the study. The current research was approved by the ethical guidelines of the Ministry of Health and Medical Education based on international documents from the Ethics Committee of the Higher Education Institute of Cognitive Sciences and the University of Tehran with ID IR.UT.PSYEDU.REC.1399.009 in the Ethics Committee of the Higher Education Institute of Cognitive Sciences. This article is noteworthytaken from the master’s thesis of cognitive science, design, and creativity with code 203-2 1401 Kh T A.
Authors’ contributions
All authors played a pivotal role in every stage of the research, from the initial design and virtual reality design to data collection and analysis, as well as the initial writing, revision, and editing of the article.
Funding
This research is not under the financial support of any institution or organization.
Acknowledgments
The authors are grateful and appreciative to the sincere cooperation of Ms. Dehghani, the head of the human laboratory of the Institute for Cognitive Science Studies, and Mona Valeh.
Conflicts of interest
The authors declared no conflict of interest.
There is no doubt that indoor environmental quality is crucial to the health and well-being of its inhabitants. It is crucial to determine the impact of these parameters on human perception to improve building design standards. Color and light are environmental factors that affect cognitive functions. Numerous studies have examined the role of lighting, demonstrating that physical environments can be designed to impact the visual, psychological, physiological, and cognitive performance of their inhabitants. The science of cognitive ergonomics is concerned with studying mental processes, including perception, memory, mental workload, inhibition, attention, interactions between humans, and systems to ensure the correct interaction between work and environment, needs, capabilities, and limitations. Therefore, paying attention to the design factors in the work environment to improve cognitive functions requires the interdisciplinary cooperation of psychologists, designers, and architects.
A comprehensive approach requires investigating and identifying potential objective and subjective measures of the work environment to improve cognitive functions in the workplace. Due to the importance of this cognitive function in different dimensions of life, the subject studied in many researches is focused on sustained attention. In addition, the studies show that cognitive functions, as well as mental health indicators are related to indoor environment parameters such as light. This study aimed to investigate the combined role of lighting intensity and color on mental workload and sustained attention in the work environment.
Methods
This research, is a clinical trial study with a quantitative approach aimed at developmental and applied purposes. The participants for this study were selected through a voluntary, non-random method based on specific entry and exit criteria following an open call for research on social networks. The Continuous Performance Test (CPT) continuous performance test was introduced in 1956 by Rosold et al. This test is used to evaluate sustained attention and impulsive movements. The task was designed to move the boxes on the conveyor belt in front of the participants, simulating the virtual environment with the actual work environment. Single-digit numbers from “0 to 9” are written on each of these boxes. The participants were required to identify the boxes with the target stimulus, considered the number “0” in this study. The NASA workload index test has been used in many studies to evaluate mental workload. This test has been used to evaluate mental workload in six subscales. The use of virtual reality as a research tool is well-established in many fields, including cognitive research. Moreover, virtual reality has a strong potential to be used as an experimental research tool in psychological and architectural research. The simulated environment in this research is a high dynamic range image model HDRI. The simulated workspace is a windowless room with artificial lighting. The color of the walls based was selected on the levels of the variables. Electroencephalography data was recorded with the help of a Q5000 EEG device (Negar Andishgan Co., Iran). This study used Ag/AgCl electrodes to record electroencephalography signals installed on an elastic cap. Thirty-two electrodes based on the international 10-20 system were installed on the participants’ heads.
At first, the experiment process was fully explained to all the participants, and the participants completed the informed consent form and the demographic information questionnaire. First, electroencephalography was recorded for 2 minutes with eyes closed before the virtual reality glasses were placed on the head. In the next step, people were asked to put on virtual reality glasses. The experiment was conducted randomly, and people encountered each of the four scenarios designed in the virtual reality environment with a wall color while their brain waves were recorded. The experiment duration for each participant was 3 hours, with steps for preparation for the electroencephalography recording.
Results
CPT task was performed to assess the significance of changes in dependent variables (accuracy, attention, inhibition, and reaction time) in different situations (four situations) of multivariate covariance analysis. Box’s M test was performed to check the equality of variance-covariance matrices to check the assumptions of multivariate covariance analysis, and this assumption was confirmed with the obtained results (F(30, 36)=2.736, P=0.005). Multivariate covariance analysis showed a significant difference in at least one of the dependent variables (F(12, 105)=2.244, P<0.05), Eta=0.20. The results of Scheffe’s test show that placing subjects in different positions significantly affect “accuracy” (F(3, 36)=9.719, P<0.05, Eta=0.44), attention (F (3, 36)=5.206, P=0.004, Eta=0.30) and inhibition (F (3, 36)=5.018, P=0.005, Eta=0.29), But there was no significant change in "reaction time" F(3, 36)=151.6, P>0.05, Eta=0.11). Scheffe’s post hoc test results showed a significant difference between the "accuracy" performance of individuals between positions 1 and 3 (P=0.003), 1 and 4 (P=0.001), 2 and 4 (P=0.21), 3 and 1 (P=0.003), 4 and 1 (P=0.001) and 4 and 2 (P<0.05), a significant difference between people’s “attention” performance between positions 1 and 3 (P=0.031), 1 and 3 (P=0.031) and a significant difference in "inhibition" in environment 1 and 3 (P=0.04), environment 2 and 3 (P=0.04) and environment 3 and 1 (P=0.04) showed.
Examining the average scores of NASA’s workload questionnaire showed that the lowest score was in the condition with a white wall and 800 Lux lighting. Furthermore, the analysis of the data in the ANOVA statistical test indicated no significant difference in the workload imposed on the individual in different situations (P<0.05) and no interaction effect between environment design and workload.
The pairwise comparison test revealed a significant discrepancy in the measured values of the normalized brain signal strength measured when each participant rested and performed the task in the four studied positions in virtual reality.
Conclusion
The present study aimed to investigate the combined role of two components of lighting intensity and color in the work environment with sustained attention and mental workload. The results showed that the interactive effect of color and light, with the combination of white and blue colors and light intensity of 300 or 800 Lux, on mental workload insignificant. This means that the design interventions resulting from the combination of these two variables did not significantly affect the scores obtained from the NASA questionnaire.
In the present study, the one-way analysis of variance of the absolute power of the frequency bands shows that when the brightness intensity increases, it does not create a significant difference in people’s attention in the electroencephalogram data. Similar to accuracy performance, inhibition performance also improves under the influence of design interventions in color and illuminance intensity. This finding can be explained using the principles of Kaplan’s theory of attention recovery and psychological recovery. Attention recovery theory emphasizes that the presence of natural elements plays a role in reducing anxiety and mental fatigue in people.
Recent studies show that the color blue can boost employees’ attention and cognitive functions. By incorporating blue into office design, organizations can enhance cognitive abilities, work performance, and overall productivity.
Ethical Consideration
Compliance with ethical guideline
This research was carried out in compliance with ethical principles, including obtaining written informed consent, the principle of confidentiality, providing sufficient information about how to conduct the research, and the freedom of the participants to withdraw from the study. The current research was approved by the ethical guidelines of the Ministry of Health and Medical Education based on international documents from the Ethics Committee of the Higher Education Institute of Cognitive Sciences and the University of Tehran with ID IR.UT.PSYEDU.REC.1399.009 in the Ethics Committee of the Higher Education Institute of Cognitive Sciences. This article is noteworthytaken from the master’s thesis of cognitive science, design, and creativity with code 203-2 1401 Kh T A.
Authors’ contributions
All authors played a pivotal role in every stage of the research, from the initial design and virtual reality design to data collection and analysis, as well as the initial writing, revision, and editing of the article.
Funding
This research is not under the financial support of any institution or organization.
Acknowledgments
The authors are grateful and appreciative to the sincere cooperation of Ms. Dehghani, the head of the human laboratory of the Institute for Cognitive Science Studies, and Mona Valeh.
Conflicts of interest
The authors declared no conflict of interest.
Type of Study: Research |
Received: 2023/12/26 | Accepted: 2024/07/11 | Published: 2024/08/28
Received: 2023/12/26 | Accepted: 2024/07/11 | Published: 2024/08/28
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