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How should homes be lit to increase the likelihood of healthy users? Ticleanu report that “A combination of bright daytime light and night-time darkness is essential for circadian entrainment and maintenance of a regular daily sleep–wake cycle. . . . Find indoor seating positions that receive abundant daylight levels but still allow for visual comfort to be maintained. For example, facing towards windows but at an angle and/or at a distance away from them so that glare does not occur, and visual task details are perceived easily, quickly and comfortably.. . .When using electric lighting, ensure it is brighter and has a cooler white colour appearance from mid-morning until early afternoon, then dim it down and set it to warmer white colour appearance towards the end of the day. . . . [after sunset] Face away from electric light sources as much as possible to reduce light levels at the eyes.”

C. Ticleanu.  2021. “Impacts of Home Lighting on Human Health.” Lighting Research and Technology, vol. 53, no. 5, pp. 453-475,

How does light experienced during the day influence sleep?  Figueiro and colleagues set out to answer this question. They used an online survey “to quantify potential changes in daytime light exposures resulting from teleworking or self-isolating at home [during the Covid-19 pandemic] and how those changes might have affected self-reported sleep quality, psychological health and emotional health. The first survey was administered in early May 2020, and the second survey was administered in September 2020. In broad terms, our analysis indicates that the greater the amount of light one is exposed to during the day (either in the home or outdoors), the better the self-reported sleep outcomes. . . .  The results suggest that spending one to two hours outdoors or staying in a bright to very bright room indoors may improve night-time sleep. These results have important implications for daytime lighting in homes, offices and schools.”

M. Figueiro, C. Jarboe, and L. Sahin.  2021.  “The Sleep Maths:  A Strong Correlation Between More Daytime Light and Better Night-Time Sleep.”  Lighting Research and Technology, vol. 53, no. 5, pp. 423-435,

Kuhn and colleagues evaluated how time in nature affects conditions in the brain. The researchers report that “A whole-brain analysis [conducted via MRI] revealed that time spent outdoors was positively associated with grey matter volume in the right dorsolateral prefrontal cortex and positive affect, also after controlling for physical activity, fluid intake, free time, and hours of sunshine. Results indicate remarkable and potentially behaviorally relevant plasticity of cerebral structure within a short time frame driven by the daily time spent outdoors. This is compatible with anecdotal evidence of the health and mood-promoting effects of going for a walk. The study may provide the first evidence for underlying cerebral mechanisms of so-called green prescriptions with possible consequences for future interventions in mental disorders.”

Simone Kuhn, Anna Mascherek, Elisa Filevich, Nina Lisofsky, Maxi Becker, Oisin Butler, Martyna Lochstet, Johan Martensson, Elisabeth Wenger, Ulman Lindenberger and Jurgen Gallinat. “Spend Time Outdoors for Your Brain – An In-Depth Longitudinal MRI Study.”  The World Journal of Biological Psychiatry, in press,

Hoki, Sato, and Kasai’s work indicates why adding carpeting to a space can be a good idea.  The researchers focused on the effects of indoor flooring in the residential environment on stress, as flooring is a feature that the human body is in contact with for long periods of time. We objectively measured the extent of psychological stress perceived while walking on carpeting and on wood flooring.” Study participants “were asked to walk on carpeting and wood flooring for 10 min each. Their electroencephalogram (EEG) and skin impedance values were measured for each task.The α-wave content percentage in EEG data and skin impedance values were significantly higher just after walking on carpet than just after walking on wood flooring.  Walking on carpeting induces less stress than walking on wood flooring.”

Yoko Hoki, Kunio Sato, and Yulchi Kasai.  2016. “Do Carpets Alleviate Stress?”  Iranian Journal of Public Health, vol. 45, no. 6, pp. 715-720.    

Chernev and Blair’s research (four empirical studies) enriches previously derived insights related to encouraging the use of sustainable options.  They report that “Prior research has suggested that consumers believe that products made using sustainable, environmentally friendly technologies are likely to underperform those made using traditional methods. . . . we argue that sustainability is likely to produce a halo effect able to attenuate [reduce] and even override the negative impact of . . . inferences underlying consumers' belief that sustainability comes at the expense of performance. . . . we identify two factors that are likely to influence the strength of the halo effect: the degree to which consumers view the company as a moral agent whose actions aim to benefit society and the degree to which moral concerns are prominent in consumers' minds. . . . managers can increase the perceived performance of sustainable products: by associating sustainable benefits with the company rather than with its products and by emphasizing the societal benefits of sustainability.”

Alexander Chernev and Sean Blair.  “When Sustainability Is Not a Liability:  The Halo Effect of Marketplace Morality.”  Journal of Consumer Psychology, in press,

Neo, Shepley, and Niederdeppe evaluated how what’s seen can influence responses to what’s heard.  They collected data in “two noise (High: 75dB LAeq, low: 30dB LAeq) and two message (noise-related visual cue or not) conditions. . . . half of the respondents saw a flyer with a noise-related visual cue (an emoji with both hands to its ears) while the other half saw a flyer without such a cue (an emoji without hands or ears). . . . a message with a noise-related visual cue placed in a noisy physical environment produced a higher ME [message elaboration] score than a message without such a cue in a noisy physical environment. . . . . This suggests the potential for . . . communicators to enhance the effectiveness of strategic messages by designing them in ways that consider physical environmental attributes in which they are likely to be experienced.”  Message elaboration (ME) was described as “an indicator of the depth of engagement with the message.”

Jun Neo, Mardelle Shepley, and Jeff Niederdeppe.  “Does Message Content Interact with the Physical Environment?  An Exploratory Study on the Influence of Noise and Noise-Related Visual Cues on Message Elaboration.”  Journal of Environmental Psychology, in press,

Ganesh and colleagues investigated how temperature influences user comfort.  They found via a literature review that “Improving indoor thermal comfort depends mainly on two major factors, air temperature, and air movement. . . . .  To improve IAQ and minimize the threat of cross-infection from various airborne diseases, the higher ACR [air change rate] at low airspeed should be used reliant on the occupancy capacity of the room.”  

Ghogare Ganesh, Shobha Sinha, Tikendra Verma, and Satish Dewangan.  “Investigation of Indoor Environmental Quality and Factors Affecting Human Comfort:  A Critical Review.”  Building and Environment, in press,

Khodasevich and teammates investigated how artificial light can support circadian rhythms.  They “measured light exposure and wrist temperature among residents of an urban area during each of the four seasons. . . . Our results demonstrate that humans are minimizing natural seasonal differences in light exposure, and that circadian shifts and disruptions may be a more regular occurrence in the general population than is currently recognized. . . . . Our evaluation of light exposure, and how it is partitioned among daytime and night-time hours, supported our hypothesis that individuals living in urban environments dim out their days and light up their nights. . . . Seasonal biology in humans is not well-understood, therefore, it is unknown what downstream effects this disconnect from natural light cycles may have on physiology and health. . . . our study revealed that differential light exposure, within the range seen in everyday life, can lead to shifts in circadian physiology within the general population.”

Dennis Khodasevich, Susan Tsui, Darwin Keung, Debra Skene, Victoria Revell, and Micaela Martinez. 2021.  “Characterizing the Modern Light Environment and Its Influence on Circadian Rhythms.”  Proceedings of the Royal Society B,

Wang and colleagues extensively reviewed links between indoor environmental quality (IEQ) and mental achievement presented in the peer-reviewed literature.  They report that “The present review decomposes IEQ into five factors—indoor air quality, the thermal environment, lighting, noise, and non-light visual factors. It divided cognition into five categories—attention, perception, memory, language function, and higher order cognitive skills. . . .  results show that poor IEQ conditions are but not always associated with reduced cognition. However, the effects of a specific IEQ factor on different cognitive functions are quite distinct. Likewise, a specific cognitive function could be affected by different IEQ factors to varying degrees. . . . Overall, there is a preponderance of the evidence that almost all IEQ factors, including indoor air quality, thermal environment, noise, lighting, and non-light visual factors could affect cognitive performance to varying degrees.” Many condition specific details are provided in the text of this article.

Chao Wang, Fan Zhang, Julian Wang, James Doyle, Peter Hancock, Cheuk Mak, and Shichao Liu. 2021.  “How Indoor Environmental Quality Affects Occupants’ Cognitive Functions: A Systematic Review.”  Building and Environment, vol. 193, 107647,

A new book reviews how future cities should be designed; conclusions are drawn from data collected during visits to 53 cities in 30 different countries and conversations with a variety of experts.  The Ideal City’s website reports that “our vision for the cities of tomorrow is built around five guiding principles. . . . A resourceful city manages to be both ecologically and economically sustainable. . . .  An accessible city is built for diversity, inclusion, and equality. . . . A shared city fosters a sense of community, collaboration, and togetherness. . . .  a safe city ensures a healthy environment to live in while providing access to resources such as food, water, shelter, and care, and fosters physical and mental wellbeing through access to healthcare and green spaces. . . . A desirable city is one that is a pleasure to be in. It is designed on a human scale, making everything accessible within a 15-minute walk.”  SPACE10, one of the authors of  The Ideal City, describes itself on the book’s website as “proudly supported by and entirely dedicated to IKEA.”

SPACE10 and gestalten.  The Ideal City. Gestalten; New York.,


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