Sensory Priorities: Workplaces

TakeAway

It’s great when there’re resources (time, money, and otherwise) to thoroughly deal with all of the sensory issues that might arise in a workplace—but that’s often not the case.  The quick answer to the question of what to do is to focus on the conditions that are farthest from optimal, but what’s worst may be challenging to identify.  Neuroscience research can guide you to the best allocations of effort when that’s the case.

In difficult situations, when no one sensory aspect of a workplace seems to be calling out louder than the rest for a fix, allocate your resources using this ranked order of generally high-priority considerations (more important ones higher on the list):

• Ventilation/Air quality/Scents
• Acoustical conditions
• Opportunities for cognitive refreshment
• Visual complexity
• Surface colors/patterns
• Lighting (artificial and natural)
• Sightlines
• Furniture design (forms that promote positive conversations and comfort, for example)
• Biophilic design (elements not already listed)
• Tactile experiences

Other sensory conditions may need to be considered during the course of any project, the ones listed here are those that are likely to be posing the greatest challenges to employee performance and wellbeing in a contemporary workplace.

Being relatively lower down on this list doesn’t mean that a sensory condition is not important, it indicates that relatively less attention can be paid to issues related to it if all sensory concerns can’t be resolved immediately.

Sensory issues related to this ranked list are always resolved in the context of a certain workplace—which means people taking action need to recognize (and have their solutions reflect) nonverbal messaging, alignment with national and group cultures, comfortable control of the environment by users, users having privacy when they desire, and support for the specific activity-at-hand.  Design that supports users’ likely personality profiles is also highly desirable.  In any workplace, conditions need to be assessed at both the individual and group levels.  Each of these issues has been addressed in Research Design Connections articles.

We’ll review research related to the first five items on the ranked list in detail after we briefly review how design can add value to a space and then the next 5 considerations on the list more briefly.

The values of design decisions made, or to be made, in monetary or other terms, are often sought and carefully reviewed when calculated.   Determining value can be complicated, or not, depending on the situation being evaluated.

For the purposes of this article, we’ll define “value” as how much something is worth.  That value might belong to the owner of whatever is being valued or others, such as society in general, or jointly to several groups.  The price for which something can be sold does not necessarily indicate its full value since true/total worth may include intangibles that are difficult to estimate s(uch as enjoyment that results from use).  In a fully informed market, the sales price reflects, but does not necessarily equal, the potential benefits that the buyer expects to receive from an item.

The Commission for Architecture and the Built Environment (CABE) has carefully considered the value created by built environments, identifying 6 types (2006):   

• Exchange value is the price that a building, etc., can be sold for in the market and can be determined via book value and return on capital, for example.
• Use value indicates how a building, etc., affects organizational performance via its influence on things such as employee productivity/performance, profits, and repeat business. It “arises from a working environment that is safe in use, that promotes staff health, well-being and job satisfaction, that encourages flexible working, teamwork and communication, and enhances recruitment and retention while reducing absenteeism.”  Use value can be calculated by determining the performance of employees, healthcare recovery rates, academic test results, retail sales/numbers of customers, or occupant satisfaction, according to CABE.   
• Image value is the contribution of the building, etc., to the reputation of the group to which it is linked, as well as to their identity.  It can be quantified via, for example, counts/analyses of public relations mentions or calculations of brand awareness/prestige, also according to CABE.
• Social value results when a building, etc., encourages “connections between people, creating or enhancing opportunities for positive social interaction, reinforcing social identity and civic pride, encouraging social inclusion and contributing towards improved social health, prosperity, morale, goodwill, neighbourly behavior, safety and security, while reducing vandalism and crime.”  Number of incidents of crime/vandalism or damage resulting from these incidents can be used to determine social value, for example.
• Environmental value is based on the repercussions of green building.  It can be calculated by determining whole life value, for example.
• Cultural value “is a measure of a development’s contribution to the rich tapestry of a town or city, how it relates to its location and context, and also to broader patterns of historical development and a sense of place.  Cultural value may include consideration of highly intangible issues like symbolism, inspiration and aesthetics.”  It can be estimated based on an analysis of reviews and press coverage, for example.    

VENTILATION/AIR QUALITY/SCENTS

Recent articles in the popular press have focused on how ventilation influences the spread of disease.  Neuroscience research makes it clear, however, that ventilation also has a significant influence on human thoughts and behaviors.  

For a full report on ventilation, read this article.  Highlights of the contents of the linked-to article are shared here.

Ventilation has a clear link to illness, which can induce stress (stress and design, and stress’ implications are discussed here), for example:   

• The air within a structure can be managed so that it’s more likely that people in it will think and act in positive ways—neuroscientists are learning how ventilation in a space can increase “breathers’” mental and physical wellbeing.  This article will address the direct psychological implications of interior ventilation.  The levels and types of chemicals released by furnishings and machinery, such as copy machines, are not discussed in this article as new materials and machines are continually being released.
• The health-related implications of ventilation-related decisions must always be considered, however.  For example, after a lit review Seppanen and Fisk reported that natural ventilation has been linked to reductions in respiratory illnesses, circulatory disease, headaches, and sick building syndrome (2002).
• Preziosi and colleagues (2004) found a 57% decrease in sick leave taken among workers in naturally ventilated workplaces, compared to people work in air-conditioned workplaces.  

As Veitch (2012) reports “The North American standard for the supply of fresh air in mechanically ventilated buildings specifies that a volume of 10L/s/person of outdoor air should be provided (ASHRAE, 2001).  The level was set with the aim of providing sufficient outdoor air to remove pollutants (including carbon dioxide created by occupants) to maintain health and comfort, and in parallel to limit energy use.”

In their 2020 book, Allen and Macomber recommend that building managers/designers “Increase the ventilation rate to a minimum of 30 cfm/person.”

Type of ventilation matters.  The BIDS research team at Carnegie Mellon University (Loftness and Snyder, 2008) “identified a number of field studies that demonstrate HVAC energy savings, health improvements, and individual productivity gains due to mixed mode or natural ventilation.  By combining the findings from these research studies, Carnegie Mellon’s BIDS team has determined that natural ventilation and mixed-mode conditioning systems can provide 47-79 percent HVAC energy savings, 0.3-3.6 percent health cost savings, and 0.2-18 percent productivity gains, for an average return on investment of 120 percent.”

McArthur (2020) simulated the experience of being in “large offices in all climate zones . . . with various outdoor air rates,” and documented the significant performance/economic benefits that result from relatively high outdoor air ventilation rates.  The researcher shares that “A benefit-cost analysis considered energy costs and carbon emission offsets to achieve net-zero carbon operation for large office buildings across international climate zones with ventilation rates ranging from 125% to 1000% ASHRAE 62.1 minimums. Key findings: (1) the productivity benefit was substantially larger than the incremental energy costs; (2) carbon offset costs were relatively low compared with energy costs and had a negligible effect on results; (3) increasing outdoor air resulted in consistently increasing net benefits on an area basis; and (4) the benefit-cost ratio was inversely proportional to the severity of the climate, with the most moderate climates actually showing a net energy decrease with elevated outdoor air.” A definition: “ANSI/ASHRAE 62.1 defines the minimum allowable outdoor air for all building types excluding low-rise residential buildings.”

There are clear benefits to enhanced building ventilation.   

• MacNaughton and colleagues (2015) report that they “estimated the energy consumption and associated per building occupant costs for office buildings in seven U.S. cities, representing different climate zones for three ventilation scenarios (standard practice (20 cfm/person), 30% enhanced ventilation, and 40 cfm/person) and four different heating, ventilation and air conditioning (HVAC) system strategies (Variable Air Volume (VAV) with reheat and a Fan Coil Unit (FCU), both with and without an energy recovery ventilator). . . .  [and] estimate[d] the economic benefit of increased productivity associated with increasing ventilation rates.”  The team learned that “Doubling the ventilation rate from the American Society of Heating, Refrigeration and Air-Conditioning Engineers minimum cost less than $40 per person per year in all climate zones investigated. . . . The same change in ventilation improved the performance of workers by 8%, equivalent to a $6500 increase in employee productivity each year. Reduced absenteeism and improved health are also seen with enhanced ventilation.”
• Allen, MacNaughton, Satish, Santanam, Vallarino, and Spengler (2016) determined, via studying people who worked in a green environment for 6 full days, that higher order cognitive function was enhanced in the environmentally responsible structure.  More details on the test conditions: study participants “On different days . . . were exposed to IEQ conditions representative of Conventional (high volatile organic compound (VOC) concentration) and Green (low VOC concentration) office buildings in the U.S. Additional conditions simulated a Green building with a high outdoor air ventilation rate (labeled Green+) and artificially elevated carbon dioxide (CO2) levels independent of ventilation.” Allen and colleagues found that “On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day. . . VOCs and CO2 were independently associated with cognitive scores. . . . Cognitive function scores were significantly better in Green+ building conditions compared to the Conventional building conditions for all nine functional domains.” At the sorts of carbon dioxide levels regularly found in indoor spaces, performance on 7 of the 9 cognitive tests administered was lower than on the same tests at lower concentrations of carbon dioxide.  Examples of the cognitive functions tested:  decision making, developing strategies and responding to crises. Study participants had a range of backgrounds including design and architecture, computer programming and engineering, as well as marketing and general management.
• Research completed by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory and the State University of New York Upstate Medical University indicates why designers need to ensure that spaces they develop have adequate indoor air quality (“Elevated Indoor Carbon Dioxide Impairs Decision-Making Performance,” 2012).  A research-related press release states that “Overturning decades of conventional wisdom, researchers . . . have found that moderately high indoor concentrations of carbon dioxide (CO2) can significantly impair people’s decision-making performance.”  Specifics on the findings:  participants were assessed “On nine scales of decision-making performance, [they] showed significant reductions on six of the scales at CO2 levels of 1,000 parts per million (ppm) and large reductions on seven of the scales at 2,500 ppm. The most dramatic declines in performance, in which subjects were rated as ‘dysfunctional,’ were for taking initiative and thinking strategically.”  The researchers warn that it is particularly important to assess indoor air quality in green, energy-efficient buildings, which are often built to be “tighter” than conventional structures.  For context: “In the real world, CO2 concentrations in office buildings normally don’t exceed 1,000 ppm, except in meeting rooms, when groups of people gather for extended periods of time.  In classrooms, concentrations frequently exceed 1,000 ppm and occasionally exceed 3,000.”
• Snow and colleagues (2019) wanted to learn more about how concentrations of carbon dioxide influence cognitive performance.  They investigated “cognitive performance. . . during short (< 60 min) exposures to normal CO2 (830 ppm) and high CO2 (2700 ppm. . .). The study was conducted in a small naturally ventilated office . . . . windows were closed while participants were in the room. . . . The chosen target for high CO2 concentration was 2700 ppm, well above guidelines for CO2 concentrations in offices (1200 ppm . . . ) and classrooms (1500 ppm), but not uncommon in occupied buildings. . . . Under normal IAQ conditions (the absence of additional pure-CO2), participants performed better in the subsequent sessions of cognitive performance testing compared to the first. . . . Critically, however, short-term exposure to the raised CO2 concentration (∼2700 ppm . . .) did not produce this expected learning effect. . . .  Individuals already lacking sleep may be more susceptible to the effects of CO2 in enclosed spaces.”
• The World Green Building Council has written an important guide for green designers and anyone else interested in the business case for environmentally responsible workplaces (2016). Among the research findings presented are “Eight Features That Make Healthier and Greener Offices”: “Indoor air quality and ventilation.  Healthy offices have low concentrations of carbon dioxide, VOCs and other pollutants, as well as high ventilation rates. Why?  101% increase in cognitive scores for workers in green well-ventilated offices.
• Obayashi and teammates (2019) studied how airflow and concentration are related.  They evaluated the mental activity of people in two areas, one with no airflow and another with an airflow system combining two different ventilation experiences, one labeled “stimualtive” and the other “mild.” During the study, “cognitive tasks are given to participants.  The concentration time ratio (CTR), which is a quantitative and objective evaluation index of the degree of concentration, is measured.  . . . the average CTR under the proposed airflow condition [the one with the mild and stimulative components] is 61.1%, while under the no airflow condition is 54.6%. The proposed airflow control shows a significant improvement in CTR.”  More information on the stimulative/mild airflow: “The velocity of mild airflow fluctuates from 0 m/s to 0.4 m/s. . . . . The transition of mild airflow velocity . . . [has a cycle of] 120 s. . . . the velocity of stimulative airflow was fixed to 1.6 m/s.  These velocities were measured at 1.1 m high, which is close to head height when the subjects are sitting.  Stimulative airflow was applied for 20 s every 10 min.”
• Al Horr and team completed an extensive literature review to learn more about how workplace design contributes to worker productivity (Al Horr, Arif, Kaushik, Mazroei, Katafygiotou, and Elsarrg 2016).  After reviewing over 300 papers, they found that “eight Indoor Environmental Quality (IEQ) factors . . . influence occupant productivity in an office environment.”   The investigators defined productivity as “the ratio of output to input,” so more sophisticated measures of employee performance are generally not discussed.  Nonetheless, the list of important factors affecting workers’ productivity identified can inform employee-supportive workplace planning. The factors linked to satisfaction and productivity by Al Horr and colleagues were: indoor air quality and ventilation, thermal comfort, lighting and day lighting, noise and acoustics, office layout, biophilia and views, look and feel, and location and amenities. “Look and feel” includes onsite aesthetics, such as colors and textures in use, floor plans, and the brand message conveyed, for example. The effects of the eight factors are interrelated: “Daylighting has direct interaction with thermal state of an office. . . . A decrease in temperature leads to improved occupant perception of indoor air quality.  Similarly, there is a crossover between daylighting and ‘look’ and outside views. . . . Also, the layout of an office can have an impact on its acoustic properties.”  In addition, “culture and values (organisational, national) have implicit effect on characteristics and norms of indoor environment quality. This also influences occupant productivity.”
• Gupta and colleagues (2018) analyzed data from two case studies to identify relationships between workplace design and productivity.  The investigators found that “There is a clear link between occupants’ perception of their environment and their perceived productivity.  When they felt too warm or too cold, they perceived their productivity to be negatively affected.  When they perceived their air to be stuffy, they also perceived their productivity to be negatively affected. . . . Task performance can be considered as a proxy measurement for productivity.  Performance was found to be negatively affected by high temperatures (particularly over 26 degrees C during the non-heating season), low RH [relative humidity] (particularly below 40%) and high CO2 concentration (particularly above 1000 ppm).” 
• Roskams and Haynes (2021) “conducted a study at two office sites. Four IEQ parameters (carbon dioxide, temperature, humidity, and illuminance) were continuously monitored at each site, and brief environmental comfort surveys were sent to employees’ smartphones four times per day across the study period. . . .    results . . . showed a strong association between environmental comfort and self-rated productivity, such that employees rated themselves as most productive when they were satisfied with noise levels, temperature, air quality, and lighting within the office. Overall, the results highlight that it is critically important to consider strategies for optimising occupant comfort, although this is unlikely to be achieved through adherence to environmental comfort boundaries alone.”
• Baker and Bernstein (2012) report that researchers have “found that task speed increased significantly in students (10 to 12 years old) when outdoor air supply rates were increased from  6.4 to 18 cfm/person, which produced a CO2 level change from 1300 to 900 ppm (Wyon & Wargocki, 2007).”   In addition, “CO2 levels and ventilation have also been shown to have a connection to average daily attendance.  In a 2004 study, Shendell et al studied 409 typical classrooms and 25 potable classrooms in Washington and Idaho, comparing indoor CO2 levels to student attendance records.  In classrooms where CO2 was measured to be regularly surpassing 1000 ppm, they saw a .5%-.9% average decrease in average daily attendance.”
• Izadi and colleagues (2019) learned that creativity is influenced by whether we’re facing into or away from the current of air movement in a room. The researchers, conducting research in laboratories and in the field, found that “frontal airflow (air blowing on the front of the body) boosts energetic activation and fuels enhanced performance on creative tasks, compared to dorsal airflow (air blowing on the back of the body).”  An important study detail: creative engagement was “operationalized . . . as improved performance on creative tasks.”  
• MacNaughton and teammates (2017) report that: “We recruited 109 participants from 10 high-performing buildings (i.e. buildings surpassing the ASHRAE Standard 62.1–2010 ventilation requirement and with low total volatile organic compound concentrations) in five U.S. cities. In each city, buildings were matched by week of assessment, tenant, type of worker and work functions. A key distinction between the matched buildings was whether they had achieved green certification. Workers were administered a cognitive function test of higher order decision-making performance twice during the same week while indoor environmental quality parameters were monitored. Workers in green certified buildings scored 26.4% [significantly] higher on cognitive function tests . . . and had 30% fewer sick building symptoms than those in non-certified buildings. These outcomes may be partially explained by IEQ factors, including thermal conditions and lighting, but the findings suggest that the benefits of green certification standards go beyond measurable IEQ factors.”  Education and job category/level were eliminated as explanations for the effects found via statistical tools. 

Allen and Macomber (2020) clearly report why it is so important to actively consider aspects of the physical environment such as ventilation and thermal comfort, during the design process: “the indoor environment is a key determinant of our health and productivity, and . . . a business strategy that focuses on the people in your building drives bottom-line performance.”  

Terrapin Bright Green has released a review of the research on how in-building ventilation influences human physical and emotional wellbeing (Walker and Browning, 2019).  The ventilation report’s website notes that “Poor indoor air quality diminishes cognitive functioning. . . . Indoor air quality management remains an industry challenge as efforts to improve air quality . . . often come at the expense of energy performance.”   In the report itself, Walker and Browning state that “symptoms associated with poor indoor air quality include headaches, fatigue, trouble concentrating and irritation of the eyes, nose, throat and lungs.  Studies have also linked long-term air pollutant exposure to impaired memory, degraded cognitive performance, disrupted sleep, increased rates of asthma, heart disease, and certain cancers. . . . Wargocki, Wyon, and Fanger estimated a 1.9% increase in office task performance for every two-fold decrease of the pollution load.”   

Ventilation systems can be designed to increase the likelihood that being in a structure will support user wellbeing and performance—neuroscience details both why and how.

POSITIVE ACOUSTICS

Soundscaping is thoroughly reviewed in this article.  Highlights of the linked-to article related to workplace design are discussed here.

Design influences the sounds that surround us in profound ways.  Neuroscience research shows how design, and resulting acoustic experiences, information we pull into our brains via our ears and skin, can boost mood, wellbeing (physical and psychological), and performance.  Emotional state, as discussed here, is important because it has a direct effect on our ability to get along with others, solve problems, and think creatively, for instance.   

Our focus in this article is on indoor noise but outdoor noise influences indoor wellbeing.  Research indicates how important it is to block the flow of environmental sound (from aircraft, trucks, trains, etc.) into buildings and to reduce outside noise levels via traffic routing/management, building orientation, etc.  Munzel and team (2018) report that “Noise has been found associated with annoyance, stress, sleep disturbance, and impaired cognitive performance. . . . studies have found that environmental noise is associated with an increased incidence of arterial hypertension, myocardial infarction, heart failure, and stroke. . . . especially nighttime noise increases levels of stress hormones and vascular oxidative stress, which may lead to endothelial dysfunction and arterial hypertension.”  The Munzel-lead group conclude that environmental noise is stressful and that it affects human bodies at a cellular level.

Nature sounds seem to have special and powerful effects on our cognitive experiences.   

• Hearing nature sounds relaxes people who are stressed.  Van Praag and team (2017) report that their “findings may help explain reported health benefits of exposure to natural environments, through identification of alterations to autonomic activity and functional coupling within the DMN [default mode network of the brain] when listening to naturalistic sounds.”  Natural sounds that are relaxing include, for example, gently moving water (think: burbling brooks) and leaves rustling in a gentle breeze.
• Natural sounds effectively support recovery from stressful events, making them good choices for the soundscapes of workplaces and other spaces where users will inevitably experience tension—particularly if it’s difficult to incorporate stress-reducing images into these environments. Benfield and team (2014) report that “Visual exposure to natural scenes can aid in recovery from stress, attentional fatigue, and physical ailments including surgery and sickness. . . . The current study extends prior work on the benefit of natural visual scenes to the domain of natural auditory exposure. [People] were exposed to an unsettling video and reliably reported worsened affective state [mood]. . . . Participants were then randomly assigned to either a natural sounds condition or to a comparison condition that was natural sounds intermingled with anthropogenic sounds (human voices or motorized vehicles). Participants exposed to a brief period [3 minutes] of natural sounds following the video showed greater mood recovery . . . than did those exposed to the same stimuli [nature sounds] also containing human-caused sounds (voices or motorized vehicles). Thus natural soundscapes can provide restorative benefits independent of those produced by visual stimuli.”  The natural sounds tested were the sounds of birds singing and gently rustling leaves.
• Research conducted by Largo-Wight, O’Hara, and Chen (2016) confirms earlier research that found that listening to nature sounds, is relaxing.  The trio share that they had participants in their study listen to silence, or nature sounds (ocean waves), or classical music (Mozart) “for 15 min[utes] in an office or waiting room-like environment. . . . [statistical tests] showed a decrease in muscle tension, pulse rate, and self-reported stress in the nature group and no significant differences in the control or the classical music groups. The significant reduction in muscle tension occurred at least by 7 min of listening to the nature sound.”
• Additional research confirms that hearing nature sounds can promote wellbeing (“Woodland Sounds Boost Wellbeing, According to New Study,” 2019).  As a press release from the United Kingdom’s National Trust reports, “The crunch of snapping twigs underfoot. Lilting birdsong from above. The rustling of trees in the breeze. Woodland sounds have been shown to have a direct impact on our wellbeing, making us more relaxed, less stressed and less anxious. A new . . . study commissioned by the National Trust explored how soaking up the sounds of the natural world affects people, and found it relaxes us more than if we listen to a voiced meditation app, and in the tests, reduced feelings of stress and anxiety by over a fifth. . . . on average, those immersed in woodland sounds such as a trickling stream, birdsong, or crunching leaves, reported a 30% increase in feeling relaxed. This is compared to no change in feeling relaxed for those listening to a voiced meditation app.” Study participants’ feelings of stress decreased by 24% and anxiety by 19%.
• A research team lead by Aradhna Krishna, a marketing professor at the University of Michigan, probed sounds that might make spaces seem safer (“What Sounds Make Us Feel Safe in Public?”  2015): “Krishna and colleagues conducted a field study in a parking garage on the Champs-Élysées in Paris and four lab experiments to examine the effects of different types of ambient noise—and no noise—on people's feelings and behavior at an underground parking lot and a simulated metro station. The researchers played classical instrumental music, bird songs and no sound at the underground parking lot. People who heard the bird songs felt a higher sense of perceived safety than those who heard the instrumental music, or no sounds. Another experiment added human vocal sounds to the mix, and it showed people reacted positively to both the bird songs and human vocal songs. Both bird sounds and human vocal sounds made people feel a social presence, which then gave them an increased sense of safety. . . . Krishna also lends a note of caution ‘to not use ambient sounds to give a false sense of security when places are actually unsafe.’” 
• Weir (2020) reports on the findings of numerous studies that have established the psychological value of nature-based experiences.   Weir states, for example, that “Berman and colleagues found that study participants who listened to nature sounds like crickets chirping and waves crashing performed better on demanding cognitive tests than those who listed to other sounds like traffic and the clatter of a busy café.”  
• Buxton and colleagues reviewed published studies on the implications of hearing nature sounds (2021).  They determined that “natural sounds improve health, increase positive affect [mood], and lower stress and annoyance. . .  .  Our review showed that natural sounds alone can confer health benefits. . . . water sounds had the largest effect on health and positive affective outcomes, while bird sounds had the largest effect on alleviating stress and annoyance.”
• Paton and colleagues (2020) investigated human responses to sounds that water can make.  They report that “16 water sounds, with very different acoustic characteristics in the number of harmonics, fundamental frequencies, spectral information and fractal dimension (=complexity), were sampled. . . .  Relationships between sound parameters and comfort responses show that information related to harmonics is behind the preferences. . . . we demonstrated that fountains with large waterfalls or jets, produce a marked acoustic aversion to humans. . . . we recommend . . . the adoption of artificial water channels with small jumps whose acoustic characteristics are ideal causing deep and sustained relaxation.” 

Acoustics Basics   

• Environments should not be completely silent (Schweitzer, Gilpin, and Frampton, 2004).  A completely silent environment (which is extremely difficult to achieve) or ones that just seem too quiet are as tension inducing as areas whose sound levels that are felt to be too loud.
• Intermittent noise is particularly stressful—think: random, unpredictable sounds (Szalma and Hancock, 2011).  Designers must take special care to shield anything (e.g., copiers, closing doors) that can make this sort of noise from people who need to be comfortable (for example, those trying to relax in an at-work spa) or trying to do cognitive work well (for example, people working away in an office).
• Ceiling surfaces, such as acoustic tiles, can be flush with the true, structural ceiling or dropped below it.  When ceilings are dropped, sound can travel from one space to another.  This is generally seen as a negative—noise pollution—but in certain circumstances, can be desirable.  For example, dropped ceilings in public bathrooms allow sound to flow out of these spaces, which can increase user safety, as discussed here. 

People start to be stressed when sound volumes exceed 45 dB(A) and become particularly uncomfortable when they reach 55 dB(A) (Veitch, 2012).  Therefore white noise should be set at this volume (45dB(A)), approximately (there’s more information on white noise in the paragraphs to come).  The white noise can then do its job of making it difficult to clearly hear nearby conversations without making people tense. In 2018, after a literature review by the National Research Council of Canada, Veitch reported that at work sound volumes of 45dB(A) are preferred. 

Background sounds of the sort that are added to public spaces, such as workspaces, are described using colors.  White and pink are the sorts most generally used.  To listen to white and pink noise, go to https://en.wikipedia.org/wiki/Colors_of_noise  and click the appropriate buttons.  Both white and pink noise are available from a number of vendors.

White noise is often added to spaces to mask sounds, increase speech privacy, and minimize audio distractions. Research has shown that it can be affective in this application.  Loewen and Suedfeld reported in 1992 that “Each of 3 groups of 15 undergraduate volunteers completed questionnaires while being exposed to 1 of 3 noise conditions (taped office noise, the same noise masked by white noise, and no extraneous noise). . . . The no-noise group performed best on a measure of cognitive complexity and felt the least disturbed and stressed by the environment. Masked-noise Ss [subjects] (1) performed better than those in the unmasked condition on integrative complexity and on a simple cognitive task and (2) felt more aroused but less disturbed or stressed by the environment.”

Hearing pink noise seems to be relaxing (Tentoni, 1978).  People sleep more soundly when they can hear pink noise; “steady pink noise has significant effect on reducing brain wave complexity and inducing more stable sleep time to improve sleep quality of individuals” (Zhou, Liu, Li, Ma, Zhang, and Fang, 2012).

Workplace soundscaping remains an important issue.  Oxford Economics surveyed over 1,200 workers from around the world (Oxford Economics, 2016).  They found that “The ability to focus without interruptions is a top priority for employees [of all ages] when it comes to office design; access to amenities like free food is far less important. . . . Nearly two-thirds of executives say employees are equipped with the tools they need to deal with distractions at work; less than half of employees agree.”  The researchers found that “Millennials are more likely to say noise distracts them from work, and in general are more annoyed by ambient noise in the office.  In fact, they are more likely to take steps—like listening to music or leaving their desks—to drown out noise and to say blocking out distractions increases their productivity and improves their mood.”  

For more information on the repercussions of audio distractions in workplaces, which have been extensively researched, read this article.  Highlights of workplace acoustics research include:    

• Oseland and Hodsman wrote an excellent introduction to psychoacoustics, which is available online, free to all (2015).  Their work makes it clear how many factors besides measured decibel levels influence whether sound is experienced positively or negatively. As Oseland and Hodsman describe, “Reported noise annoyance does correlate with sound level measurement, but it is generally accepted that the sound level accounts for only 25% of the variance in [relative amount of] annoyance. The research literature assessed for the purposes of this report suggest that there are four key non-physical factors that affect noise perception and performance in office environments: Task and work activity[;]  Context and attitude [toward the people creating the noise, the perceived need for the noise, whether the noise source is perceived as being useful, etc.][;]  Perceived control and predictability[;] Personality and mood. . . .  Noise is clearly a psychophysical matter and it relates as much, if not more, to the interpretation and meaning attached to the sound and how distracting it becomes as to the sound level per se. . . . The solution to noise distraction is as much to do with the management of the space and guidance on behaviour as it is about the design and acoustic properties.”
• Colenberg, Jylha, and Arkesteijn (2020) did a literature review to learn more about how office interior design influences the physical, psychological, and social wellbeing of workers.  They determined that “open-plan offices, shared rooms and higher background noise are negatively related to health. . . . working in open workplaces with six or more occupants tends to have a negative relationship with well-being if there are no enclosed workspaces to divert to, as provided by ABW environments. . . . Activating furniture [e.g., sit-stand desks] is found to have few or mixed health effects despite reducing static sitting time. . . . Regarding real plants in the workspace, field studies find a positive influence on health. . . . high levels of background noise and speech intelligibility in the workplace negatively affect both physical and psychological wellbeing.  A higher sound level causes high self-rated fatigue. . . . Features that encourage physical activity, including sit-stand and bike desks, and increased distances to communal facilities, are found to have a positive relationship with physical well-being.”  Greater levels of daylight, more individual environmental control, in-office plants, and views outside the office were tied to higher levels of physical and social wellbeing.  Individual control was defined as including the ability to adjust workspace conditions and to personalize work areas.  Higher levels of both control of conditions and ability to personalize were linked to greater levels of psychological wellbeing.  Interestingly, when people have actual control of one component of the environment they perceive that they have control over other environmental elements also.   Social wellbeing relates to issues such as interpersonal relations, while psychological wellbeing links to privacy and mood, for example.  Physical wellbeing involves physical health, for instance.
• Finnish researchers have determined that noise made by nearby workers has a persistent negative effect on individual performance (Haapakangas, Hongisto, Hyona, Kokko, and Keranen, 2014).  This issue is important because, as the Finnish team states, even “Unattended [not noticed] background speech is a known source of cognitive and subjective distraction in open-plan offices.”  In the course of the study directed by Haapakangas, “four acoustic conditions were physically built. Three conditions contained background speech. A quiet condition was included for comparison. The speech conditions differed in terms of the degree of absorption, screen height, desk isolation, and the level of masking sound. The speech sounds simulated an environment where phone conversations are heard from different locations varying in distance.” The researchers found that “The reduction of the STI [Speech Transmission Index] by room acoustic means decreased subjective disturbance, whereas the effects on cognitive performance were somewhat smaller than expected. . . . reducing the STI is beneficial for performance and acoustic satisfaction especially regarding speech coming from more distant desks. However, acoustic design does not sufficiently decrease the distraction caused by speech from adjacent desks.”  Acoustic design alone does not resolve nearby noise-related distractions.
• Herff, Dean, and Schaal (2020) probed memory performance in noisy and quieter spaces.  They report that “Disruptive effects of background noise on memory have been thoroughly investigated. . . . we explore whether and how unintelligible multiple talker background babbling affects melody recognition. . . . Our results suggest that if possible, background noise should be avoided as it negatively affects memory performance. However, if encoding [mental processing of information so that it can be stored in the brain] is likely to take place in a noisy environment, then presenting background noise during retrieval may be beneficial. This is because matching background noise during encoding and retrievals appears to reduce cumulative disruptive interference.”  Matching noise conditions can thus enhance cognitive performance.
• Acun and Yilmazer (2018) investigated soundscapes in open-plan offices.  They found, using surveys, employee interviews, onsite measurements of sound volumes, and simulations of offices that “Sounds that were not expected or out of context and those that interfere with the concentration demanding tasks caused a negative interpretation of the soundscape. . . .  employees were concerned with silence as much as they were concerned with the noise.”  In too quiet spaces, workers become worried about acoustic privacy.   In summary, “Both a very loud and a very quiet office environment can cause a negative effect on factors such as task performance, satisfaction and wellbeing.” Employees carefully consider and interpret the sounds that surround them: “when sound is heard by the listener, they search for pieces of information within it. . . . objective measurements alone do not reflect individuals’ perception of the soundscape.” 

Browning and Walker (2018) effectively summarize much of the current research on workplace psychoacoustics in their report.  As they state, “In one study, self-reported time wasted decreased by more than 55% following the installation of an active acoustic treatment system. . . . . White or pink noise—broad-band noise commonly used in conventional sound masking systems—can irritate listeners over time and may actually exacerbate stress and dissatisfaction in the workplace. . . .   In at least two field experiments . . . participants rejected sound-masking systems altogether in favor of unmasked background noise. . . . When compared to conventional white noise, natural soundscapes have shown to increase performance on tasks and improve positive perception of wellbeing. . . . In a study of speech masking and cognitive performance, water outperformed four other masking sounds for serial recall and creative thinking. . . . Water sounds broadcast synchronously with a video of running water resulted in participants reporting greater restoration, and outperformed all other tested sounds, even that same water sound without video pairing.”   

ENABLING COGNITIVE REFRESHMENT

Many activities require mental concentration/focus and humans become cognitively exhausted after doing work that requires them to concentrate (Gifford, 2014).

Neuroscientists have determined how the design of indoor environments can help us mentally refresh. What they’ve learned can be used to develop spaces where people work to their full potential and lead pleasant lives.

Workplac users must have an opportunity to mentally revitalize their tired brains, how to support cognitive refreshment is discussed in detail in this article. 

Why should we be concerned about creating spaces that are restorative?    Cognitive restoration is important because when we’re mentally exhausted, not only is our brain’s performance degraded, we also become more irritable and don’t get along as well with others (Gifford, 2014).

Pheasant and colleagues (2010) investigated the experience of being in environments that are restorative and “enable us to recover out sense of well being.”  These places “need to comprise sufficient sensory stimulation to keep us engaged, whilst at the same time providing opportunity for reflection and relaxation.”  The researchers verified that auditory and visual stimuli both influence whether an experience is restorative; the elements of restorative environments are fully outlined below.

This article will not cover spending time outside or the design details of restorative outdoor gardens, parks, etc. For more information on those topics, please read this article on the design of therapeutic landscapes, for example.  

Being in an environment with opportunities for restoration, whether nature-focused or otherwise, can have significant advantages, for example:  

• Viewing nature improves mood as well as our ability to concentrate (van den Berg, Koole, and van der Wulp, 2003).  For more information on why mood matters, read this article (spoiler alert, when we’re in a better mood, we’re more apt to think creatively, reason effectively, and get along with other people).  
• Berman, Jonides, and Kaplan found that taking a nature walk or looking at pictures of nature improves cognitive functioning, particularly when compared to the cognitive ramifications of looking at urban pictures or taking a walk in a city (2008).
• Research conducted by neuroscientists, using functional MRI machines, confirms that views of nature not only reduce human stress levels, but support our return to productivity after we’ve been mentally exhausted by work requiring concentration/focus (Kim, Jeong, Baek, Kim, Sundaram, Kang, Lee, Kim, and Song, 2010). 
• Grassini and colleagues studied the psychological implications of viewing nature and urban scenes and their findings are consistent with previous research (2019).  The investigators report that “During EEG [electroencephalography] recording, the participants . . . were presented with a series of photos depicting urban or natural scenery. . . . Our data suggest that the visual perception of natural environments calls for less attentional and cognitive processing, compared with urban ones. . . . Subjects rated the images of natural scenery as more relaxing than the urban ones, and the images containing water elements as the most relaxing. . . . In summary, our electrophysiological results suggest that perception of natural environments, even when depicted in static images, is less attentionally and cognitively demanding for the human brain, compared to perception of urban ones.”  
• Berto (2014) found that looking at scenes of nature, live or as still or moving images, influences the activity in our brains.  When we do so, our alpha wave frequencies indicate we “are less aroused physiologically and more relaxed, but wakeful. . . . EEG studies identify tranquility as an outcome of viewing natural settings. . . . In general, exposure to nature enhances sense of attachment, social life, mental and physical health, quality of life and the occurrence of activities and events that enhance wellbeing.” Seeing nature videos, for example, has been tied to speedier recovery from stressful situations and better ability to put up with frustration (Berto, 2014).  

Restorative Views

Much of the earliest research on cognitive restoration focused on being in areas with views of nature, although more recent research indicates that other sorts of environments are also restorative.  This initial research with natural environments has been effectively summarized by Gifford (2014), “Merely looking at nature seems to help restore people.”  Visual art can be cognitively restorative, helping us rebuild our mental processing power after it’s been depleted by things such as knowledge work that require us to focus on the task at hand. Viewing realistic scenes of nature in artwork is restorative and reduces stress (Gifford, 2014).   Veitch reports that views of nature through windows or of realistic images/art depicting nature help workers restock their mental energy levels after doing work requiring concentration, which has positive implications for performance (Veitch, 2012).  

Norwood and colleagues (2019) reviewed published peer-reviewed studies (some had taken place in labs, using images, for example, others were more true-to-life or used virtual environments) to learn more about how environments influence brain activity and mood.  They found that “Natural environments were associated with low frequency brainwaves and lower brain activity in frontal areas, indicating comfortable and subjectively restorative feelings.  Urban environments appear to induce brain responses associated with negative affect (demonstrated in an overactive amygdala region).  Furthermore, urban environments were associated with activation of the posterior cingulate cortex associated with top-down processing/effortful attention. . . . When participants indicated preference for a particular design feature in the natural or non-natural environment, this preference was accompanied by delta, theta and alpha activity that indicated favourable mood states. . . . Exposure to natural environments was associated with positive self-reported feelings of relaxation, restoration, and comfort or preferences, higher alpha on EEG and low activation on fMRI and NIRS [near-infrared spectroscopy].” Also, “the realism of an experimental condition, and therefore validity of participant responses, is greater when more senses are engaged.”

Korpela and team investigated restorative experiences at work (Korpela, de Bloom, and Kinnunen, 2015).  They report that “A [physiological study] has indicated that people are less nervous or anxious when looking at the window view to nature compared with the window view to the city or no window view.” Visible water helps us restock our mental energy after it’s been depleted (White, Smith, Humphreys, Pal, Snelling, and Depledge, 2010). White and colleagues found that “as predicted, both natural and built scenes containing water were associated with higher preferences, greater positive affect and higher perceived restorativeness than those without water. . . . Intriguingly, images of 'built' environments containing water were generally rated just as positively as natural 'green space.'" White and colleagues found the same effect whether water was naturally occurring, such as a river, or not (for example, a fountain).

Nature views that are perceived to have the most potential to restore us share certain attributes (Herzog, Maguire, and Nebel, 2003).  They have “open views [that means that when we look into the scene our gaze isn’t obstructed by something such as tree branches], smooth ground surfaces, and signs of setting care.”  For restoration, we need to feel that we could walk easily through the space viewed, but if it is so open that being in it would leave us feeling exposed and without a few places we could hide or take refuge, the view is perceived to be less restorative.

Browning and colleagues (2020) have determined that virtual nature experiences can have the same effects on mental health as “real” ones.  The team reports that “Nature exposure in virtual reality (VR) can provide emotional well-being benefits for people who cannot access the outdoors. . . . [the researchers compared] the effects of 6 min of outdoor nature exposure with 6 min of exposure to a 360-degree VR nature video, which is recorded at the outdoor nature exposure location. Skin conductivity, restorativeness, and mood before and after exposure are measured. We find that both types of nature exposure increase physiological arousal, benefit positive mood levels, and are restorative compared to an indoor setting without nature; however, for outdoor exposure, positive mood levels increase and for virtual nature, they stay the same. . . . Settings where people have limited access to nature might consider using VR nature experiences to promote mental health.”

Van Esch and colleagues (2019) carefully evaluated the implications of various views to the outdoors from office windows and found that “amount of nature in the employees’ window views was positively associated with restoration and job satisfaction [more nature, more restoration and job satisfaction] and negatively with emotional exhaustion, turnover intent, and apprehension.  . . . for both those with natural and urban office views. . . . . people were uncomfortable with incoherent, illegible, and complex views – in both natural and built settings. . . . individuals with coherent built views were less apprehensive, felt more restored, and were more satisfied with their jobs. . . . Coherent views are legible and interpretable, allowing the viewer to understand dimensions and orientation – for example, a savannah-lie landscape. . . . A legible view is interpretable and allows the view to predict its dimensions and orientation. . . . Complexity refers to views that have many different elements, such as a farmer’s market, which offers many shapes, colours, and textures.”  

Green roofs are getting to be relatively common in cities; people renting offices and homes now often can choose between several green roof views.  Lee and team (2014) learned that “all living [green] roofs were preferred over the concrete roof; however preferences differed according to vegetation characteristics. The most preferred and restorative living roof had taller, green, grassy and flowering vegetation, while lower-growing red succulent vegetation was least preferred.”  So, rooftop “prairies” are preferred and also more restorative. 

Additional research also indicates that seeing a green roof helps employees restock mental energy depleted by work that requires focus (Loder and Smith, 2013).  Loder’s doctoral research focused on green roofs in downtown Toronto and Chicago.  Although some participants in her study “thought the prairie-style green roofs on Chicago’s city hall were beautiful and most visitors found these roofscapes more interesting than sedum green roofs, they didn’t always like the messy look of the green roofs and associated it with neglect. However, participants who had close access to the wilder green roofs over time, and who could watch them change through the seasons, felt calmer, had better concentration, improved creativity for problem-solving, and a heightened sense of hope. . . . They also found that the wilder green roofs provided a respite from the fatigue of concrete, steel, and glass of the city . . . though one would expect that participants would prefer the neat sedum green roofs, which, from a distance, often look like a mown lawn—the research shows that viewers were less interested in them and associated them with a lack of care and effort, particularly if the green space did not cover the entire roof.”

Looking at green roofs even very briefly has benefits (Lee, Williams, Sargent, Williams, and Johnson, 2015).  Lee and colleagues learned that “micro-breaks spent viewing a city scene with a flowering meadow green roof . . . boost sustained attention. Sustained attention is crucial in daily life and underlies successful cognitive functioning. . . . Participants who briefly [for 40-seconds] viewed the green roof [did a better job on cognitive tasks than] participants who viewed the concrete roof.”

Lee and colleagues (2018) found that viewing green roofs for short periods of time (90-second micro-breaks) helped people feel less tense while boosting cognitive performance. The researchers defined micro-breaks as periods “unrelated to work that can occur between tasks when employees proactively direct their attention away from work. . . . They could last just seconds-to-minutes . . . and even occur during brief glances through the window.” Participants in the Lee-lead study took micro-breaks in each of the following conditions:  “in an upper-story meeting room at a city university campus. They overlooked a roof with views of the city beyond. In the control micro-break condition, to simulate a roof typical of commercial buildings, a grey concrete colored mat covered the existing roof. In the green micro-break condition, a green roof consisting of a meadow with tall, green grass and yellow flowers covered the roof.”  

Yin and colleagues (2018) created two virtual reality indoor environments and had participants in their study spend 5 minutes in each. They also spent 5-minutes in the “real” environment presented via virtual reality; the virtual reality spaces were exact copies of these “real” places.  The researchers found that “The indoor biophilic environment was associated with a decrease in participants’ blood pressure.  . . .  Short-term memory improved by 14% [in the biophilic space compared to the non-biophilic one].  Participants reported a decrease in negative emotions and an increase in positive emotions after experiencing the biophilic setting.  . . . participants experiencing biophilic environment virtually had similar physiological and cognitive responses as when experiencing the actual environment.    This gives rise to the possibility of reducing stress and improving cognition by using virtual reality to provide exposures to natural elements in a variety of indoor settings where access to nature may not be possible.” The non-biophilic environment was described as “a classroom that does not have windows or indoor plants,” while the biophilic environment was  “an office common area with plants, bamboo floor and external views of green space and a river.”

Yin and teammates have continued to study the implications of being in indoor biophilic spaces using virtual reality (2020). They report that “Participants were randomly assigned to experience one of four virtual offices (i.e. one non-biophilic base office and three similar offices enhanced with different biophilic design elements) after stressor tasks. Their physiological indicators of stress reaction, including heart rate variability, heart rate, skin conductance level and blood pressure, were measured by bio-monitoring sensors. . . . We found that participants in biophilic indoor environments had consistently better recovery responses after stressor compare to those in the non-biophilic environment, in terms of reduction on stress and anxiety. Effects on physiological responses are immediate after exposure to biophilic environments with the larger impacts in the first four minutes of the 6-minute recovery process.”  Also: “In the stressor period, participants were exposed to a virtual office with untidy conditions and background noises from traffic, machinery and household appliances. They were instructed to finish two stress induction tasks (i.e. memory task and arithmetic task).” Biophilic design elements utilized included plants, water (a fish tank), natural materials, biomorphic shapes, and views of nature, for example. 

Determan’s team (2019) present a concise but useful review of the effects of biophilic design on student/teacher experiences/learning outcomes as well as the results of field research they conducted at a Baltimore public charter middle school (in math classrooms).  Their work is lavishly illustrated with images that convey important information visually.  The discussion of fractals in the literature review is particularly useful, for example: “Experiences of fractals in the built environment that have the characteristics of those most found in nature lead to measurable stress reduction responses. . . . both non-fractal artwork and high-dimensional fractal artwork have been shown to induce stress.” In the original research conducted by Determan and colleagues, student performance and experience (generally) were compared in a traditional classroom and one that had been biophilicly enhanced via the addition of a garden featuring evergreen and deciduous plants outside the classroom window that could be seen by students during class, installation of motorized translucent roller shades (complete with an imprinted tree image) that were raised or lowered automatically based on sunlight levels at the window where they were mounted (these blinds replaced opaque mini-blinds),  and  application of nature-inspired patterns to some classroom surfaces (images of these patterns are available in the text).  Outcomes of the study conducted by the Determan team include: “Students felt significantly more positive in the biophilic classroom when compared to the control classroom regarding physical space, their enjoyment of math lessons, and their level of involvement. Students claimed to feel ‘more relaxed’, ‘calm’, ‘better able to concentrate’, ‘easier to focus’ and have ‘more of a purpose to learn’ in the biophilic classroom when compared to their other classrooms. . . .  Improvement in average Math test scores over a 7 month period was more than 3 times higher in the biophilic classroom when compared to a control classroom.  After 7 months in the biophilic classroom, 7.2% more students tested at grade level than control classroom students.” The sorts of fractals found in natural environments have been linked to lower stress levels as well as mental refreshment.   For more information (and images) related to natural fractals, visit this Wikipedia page. 

Taylor and Spehar (2016) report that seeing moderately complex fractals reduces stress: “Humans are continually exposed to the rich visual complexity generated by the repetition of fractal patterns at different size scales. Fractals are prevalent in natural scenery [for example]. . . . we . . . investigate the powerful significance of fractals for the human visual system. In particular, we propose that fractals with midrange complexity (D = 1.3–1.5 measured on a scale between D = 1.1 for low complexity and D = 1.9 for high complexity) play a unique role in our visual experiences because the visual system has adapted to these prevalent natural patterns. . . . the visual system processes mid-D fractals with relative ease. This fluency optimizes the observer’s capabilities (such as enhanced attention and pattern recognition) and generates an aesthetic experience accompanied by a reduction in the observer’s physiological stress levels.”  

Terrapin Bright Green is making available, at their website, a useful resource for designers interested in incorporating fractals into their projects (Trombin, 2020).  Terrapin describes the newly available report on the website from which it can be downloaded, which is shared, below: “Fractal patterns are an intricate ubiquitous machinery behind nature’s order. . . . The unique trademark of nature to make complexity comprehensible is underpinned by fractal patterns, which apply to virtually any domain of life; to the design of built environment, fractal patterns may present opportunities to positively impact human perception, health, cognitive performance, emotions and stress.  Yet, designing with fractals can also come with implementation challenges.  This paper provides a high-level conceptual framework for thinking about design with fractals, and for promoting restorative and satisfactory environments, with a focus on the indoor environmental quality. This paper includes primary scientific research on fractals, perception and health, metrics and terminology used to describe fractals, and perspectives on design, technology and other factors than (sic) may influence the creation of fractal patterns for design projects.” The Trombin report shares information on design tools/software that can support designing with fractals. For more information on fractals and how they can be used by designers to achieve particular, planned, outcomes, read this article.   

A view of an urban environment that is fascinating is restorative (Berto, Baroni, Zainaghi, and Bettella, 2010). As Berto and team report, “Both built and natural environments can be restorative if high fascination.”  Berto and colleagues provide additional information: “Fascinating stimuli attract people and keep them from getting bored, but most important they allow people to function without having to use directed attention. . . . the fascination process is not engaged merely by random sequences of interesting objects, but rather by elements related to one another. In other words, a fascinating stimulus has to be connected to a larger framework, otherwise it is only a momentary diversion or distraction. . . .  A restorative place has to look like a place where you would take a break (being-away), it must be large enough to permit real or imagined exploration (extent), and it must not interfere with your purposes/interests (compatibility).”

Collado and Manrique move awe-related research in a new direction (2020).  The team studied how cognitively refreshing/restorative it is to view “awe-evoking scenes (natural/built) [via images] compared with mundane scenes (natural/built). . . . we found positive [but not statistically significant] effects of exposure to awe-evoking scenes [on mental restoration/refreshment]. . . .  Our findings concur with previous findings of positive effects of exposure to different visual stimuli . . . Natural awe-evoking images, for instance, on large posters and screens, are probably being used in places where people’s attentional resources are often depleted (e.g., workplaces, schools, and hospitals). Considering our results, built awe-evoking scenes could also be used when seeking to enhance people’s attentional resources. Given that people are attracted to scenes outside their everyday environment, practitioners should consider people’s everyday surroundings when choosing scenes to place in settings where attentional resources are especially needed. For instance. . . . extraordinarily high and modern buildings may evoke a stronger feeling of awe in people living in areas where low and medium/sized buildings are common.” For more information on awe, how to create awe-inspiring situations, and the ramifications of being awed, read this article.  

Restorative Materials  

• Fell’s dissertation project investigated the restorative effects of wood in interior spaces (2010).  Fell found evidence that “wood provides stress-reducing effects similar to the well studied effect of exposure to nature in the field of environmental psychology.”  This lead Fell to the conclusion that “wood may be able to be applied indoors to provide stress reduction as a part of the evidence-based and biophilic design of hospitals, offices, schools, and other built environments.”  This research is particularly important because wood can be used in any sort of space—for example, ones without views of nature or that cannot support plants.  The wood included in the test environment was birch veneer office furniture with a clear finish.
• Lipovac and Burnard (2021) review published research related to looking at wood (physical or virtual indoor interactions with real or imitation wood) and reach the conclusion that “Studies with longer exposure times to wood generally observed improved affective states [moods] and decreased physiological arousal in wooden settings. . . . Current evidence suggests that visual wood exposure may improve certain indicators of human stress. . . . Current research suggests that visual wood exposure could lead to beneficial outcomes.”
• People seem to be both more relaxed in spaces featuring wooden surfaces and also better able to concentrate in them (Augustin and Fell, 2015, reporting on work done by Yuki Kawamura not yet published in English).
• Covering about 45% of surfaces with wood seems to be a magic dose.  In a 2007 study, Tsunetsugu, Miyazaki, and Sato measured blood pressure in rooms where 0%, 45%, or 90% of surfaces were covered with wood with visible grain.  While blood pressure was lowest in the room with 90% wood surfaces, the room with 45% wood surfaces was preferred by study participants and this was the room that was rated as most comfortable.  In a study conducted by Masuda and Yamamoto in 1988, people looked at photos of living rooms and evaluated the spaces viewed.  Rooms were rated as more pleasantly relaxed as the percent of surfaces covered by wood increased to 43%; after that relative amount of wooden surfaces, spaces were seen as less warm (i.e., pleasantly relaxed).
• Kelz, Grote, and Moser studied stress levels in Austrian classrooms, and learned that students were less stressed in classrooms that used predominantly wood finishes than students in classrooms that were not wood-dominate (2011).
• Zhang, Lian, and Ding (2016) collected data in four different test rooms.  In one, all interior walls were steel painted white.  Three other spaces had varying numbers of unpainted, wooden walls, but in each of these three conditions, the data collected were comparable.  These three spaces, all categorized as “wooden” had walls that were either covered 100% with dark brown wood (which looked a lot like tree bark and had a rounded, log like shape), 100% with light brown wood (which looked a lot like planed planks), or a mix of 50% light brown wood and 50% white-painted steel.  The ceilings in the test rooms were not described.  The difference between the test rooms with all white walls and those with some—or all—wooden walls seems quite dramatic and it would have been interesting to see comparisons between, for example, experiences in rooms with walls painted brown and in ones with wooden walls. Zhang, Lian, and Ding found that after people had been in the environments tested for an hour “More positive emotions were generated in wooden environments than in non-wooden environments. . . . fatigue evaluation values of wooden environments were dramatically lower than those of non-wooden environments after continuous working [mental effort], which implied that the participants in wooden environments suffered from less fatigue. . . . Compared to non-wooden rooms, wooden ones were considered as more comfortable environments.” 

Indoor Plants and Restoration

Raanaas, Evensen, Rich, Sjostrom, and Patil (2011) determined that cognitive performance is better in offices with plants than without plants because those plants help people restock their mental processing power after they deplete it doing work that required focus.   The influence of plants was tested in a classic sort of experiment.  Some study participants did knowledge-work-like test tasks in an office without indoor potted plants and others did the same things in the same office with indoor potted plants present.  In both cases, they worked at a desk beside a window with a view of a large lawn, other buildings, and deciduous trees.  Since this study was conducted in Norway during the winter, there weren’t any leaves on those trees.  Four plants were placed in the office during the “with plants” tests.  Two of those plants were flowering, and they were on the windowsill beside the working study participant.  The other two plants did not have flowers.  The flowering plants were two pink Phalaenopsis and the two foliage plants were a 30 cm tall Aglaonema commutatum placed on the work surface and a 120 cm tall Schefflera arboricola standing on the floor between the desk at which subjects worked and a book shelf. More details on this study:  “Attention capacity was assessed three times, i.e. immediately after entering the laboratory, after performing a demanding cognitive task, and after a five-minute break. . . . Participants in the plant condition improved their performance from time one to two, whereas this was not the case in the no-plant condition.”

Nieuwenhuis and team confirmed the value of adding plants to workplace environments (Nieuwenhuis, Knight, Postmes, and Haslam, 2014).  In a series of experiments, most involving actual workplaces and workers and with data collected over long periods of time, the investigators found that “enriching a previously lean office with plants served to significantly increase workplace satisfaction, self-reported levels of concentration, and perceived air quality. . . . enriching space also improved perceived productivity. . . and actual productivity. . . . simply enriching a previously spartan space with plants served to increase productivity by 15%. . . . a green office leads to more work engagement among employees. . . . the results unambiguously indicated that participants who worked in green office space were more productive than their counterparts who worked in a lean office space. Tasks were completed faster and— importantly—without any accompanying rise in errors.”  Plants used by the researchers were green, leafy (as opposed to cactuses), and had an average height of 90 centimeters (about a yard).  In “green” test conditions, subjects could see at least one, and generally between one and three of these plants while working.  No plants were visible to participants working in lean spaces.

Hall and Knuth (2019) reviewed published research related to human experiences in spaces with indoor plants and report that: “Interior plants can lead to healthy, productive workplaces through enhanced attention capacity, lower stress levels, and higher job satisfaction from viewing plants. . . . biophilia in architecture. . . . can reduce stress, enhance creativity and clarity of thought, and improve well-being in urbanized communities (Browning et al. 2016). . . . Visible greenery. . . reduces stress and increases the ability to concentrate. . . . employees who had a view of plants completed the test 19% faster than employees in a room without a view of plants (Nieuwenhuis et al, 2014).  Offices in the Netherlands and Great Britain experienced a 15% increase in worker productivity when plants were included in office space.”

Van den Berg, Wesselius, Maas, and Tanja-Dijkstra investigated green walls with living plants in a new context, elementary school classrooms (pupils aged 7 to 10) (2017). They found that “children in the four classrooms where a green wall was placed, as compared with children in control groups [comparable classrooms without green walls], scored better on a test for selective attention. . . . The green wall also positively influenced children’s classroom evaluations.”  So, students rated classrooms with green walls more positively and were also better able to pay attention and focus in classrooms with green walls. The green walls installed were described as “a closed system, which consists of a metal frame with layers of felt, which provide fertile soil for the plants. . . . In each classroom, a single wall unit of 1.25 m wide and 2 m high was placed in the back of the room against the rear wall or in one of the corners against a sidewall. The unit was stocked with eight types of green plants, including Spathiphyllum, Philodendron, and Dracaena.”

For additional information on research related to indoor plants, read this article.  

Refreshing Art

As noted earlier, and as discussed in this article, art can encourage mental refreshment.

Veitch reports that realistic images/art depicting nature help workers restock their mental energy levels after doing work requiring concentration, which has positive implications for performance (Veitch, 2012).

Aquariums and Restoration

Watching fish swim in an aquarium is good for our mental wellbeing, reducing stress, for example (Berry, Parker, Coile, Hamilton, O’Neill, and Sadler, 2004).

Cracknell researched the cognitive implications of watching fish swim in an aquarium (2012).  Her work “extend[s] previous work by exploring the effect that varying biodiversity can have on these responses.”  Findings “suggest that even watching an empty tank may be physiologically and emotionally restorative but that the presence of fish improves these effects further . . . the Medium biodiversity tank produced the most restorative effects but differences from Low biodiversity were rarely significant . . . given the pattern of data, we predict significant improvements during the next phase of restocking when biodiversity will increase yet further.”  The researcher reports on the types and numbers of fish used in each test condition, but not the size of the aquarium.  All study participants viewed the fish tank for 10 minutes before information was collected about the effects of the tanks on their psychological states.

Multiple Simultaneous Effects

Sona and colleagues (2019) determined that “SEBEs [sensory enriched break areas] simulating either a natural [outdoor] or a[n indoor] lounge environment were perceived as more pleasant and restorative . . . than a standard break room, which in turn facilitated the recovery of personal resources (mood, fatigue, arousal). . . . Viewing a natural environment was perceived as more pleasant for sensory input and more restorative than viewing a lounge environment, which in turn increased recovery effects. . . . simulating restorative environments in a break room may promote recovery best by creating sensory-rich impressions of natural environments. . . . using an additional congruent scent enhanced the room pleasantness of the simulated audiovisual environment and indirectly intensified the recovery effects on mood, arousal and reduced fatigue.”  Sounds heard by participants in the Sona-lead study were “bird sounds in the natural outdoor condition . . . and instrumental music in the built indoor condition.” Also, odors added to the natural outdoor condition were “a scent composed of rosewood, geranium, ylang-ylang, olibanum (frankincense) and hyssop” while in the built indoor conditions the scents of rosewood and cardamom were added.  Break rooms were experienced for 15 minutes and all scents were able to be detected by study participants but were not strong enough so that they could be identified by them.   This study’s findings are relevant not only to break room design, but as the researchers suggest, also to waiting areas, among other spaces.

MANAGING VISUAL COMPLEXITY

Visual complexity is a key driver of experience.  Both too much and too little are bad for our mood and cognitive performance.  Completed research reveals how the amount of information we pick up from the world around us influences our mental and physical state, how to determine how visually complex our world is, and instances in which we must be particularly careful to guard against excessive visual complexity, disorder, and clutter.

Visual complexity is discussed in detail in this article. 

By surveying a range of different scenes and items viewed, Nadal, Munar, Marty, and Cela-Conde learned that visual complexity is determined by the number of different elements present, and their organization (2010). Scenes with more colors and clutter are generally seen as more complex and more open scenes tend to be categorized as less complex (Oliva, Mack, Shrestha, and Peeper, 2004). As Chaparro and Chaparro report, color can be used to reduce visual clutter when multiple items are the same shade, particularly if those “same-colored” elements are next to each other (2017).

Visual complexity can be measured by experts using sophisticated computer programs and complicated mathematical algorithms.  The most practical way to assess visual complexity, without computers and calculators, is to compare an existing or potential space to one with known visual complexity.   

The interiors of homes designed by Frank Lloyd Wright generally have moderate visual complexity (for example, take a look at the interior of the Meyer May House. Describing Frank Lloyd Wright interiors as having moderate visual complexity is supported by calculations included in Vaughan and Ostwald (2014). This link will bring you to images of the Willson Hospice House, where moderate levels of visual complexity are also seen in the interior common spaces. Additional examples:  the Japanese flag has low visual complexity while the United States flag is very visually complex; the Canadian flag has moderate visual complexity.

There are clear advantages to designing in moderate visual complexity.    

• Moderate visual complexity is preferred, in general (Berlyne, 1971); scenes with moderate levels of visual complexity are preferred to views that are less and more complex (Vitz, 1966).  Also, people would rather look at scenes/artwork/patterns that are moderately complex (Forsythe, Nadal, Sheehy, Cela-Conde and Sawey, 2011). For information on the many desirable implications of having preferred sorts of experience, read Some of Our Favorite (and Not So Favorite) Things. Seeing favored forms can boost mood, support better problem solving and creative thinking, and smooth our interactions with others, just for starters.
• Moderate visual complexity has been linked to environmental satisfaction (Kaplan, 1987).
• Lindell and Mueller reviewed the research literature, confirming that art with moderate visual complexity and symmetry is preferred to more or less complex or unsymmetrical images; more symmetrical images are also seen as more beautiful (Lindell and Mueller, 2011).  These are the conditions most likely to be found in comforting natural spaces.  
• Cupchik’s analysis supports efforts to provide users with moderate visual complexity (in press).  As he reports “Experimental aesthetics was founded in 1867 by Gustav Fechner and reinvigorated by Daniel Berlyne in 1974. . . . Berlyne used enhanced stimulus control and behavioral techniques to support Fechner’s idea that people prefer moderate levels of complexity.”
• Symmetry generally reduces the amount of perceived complexity (Leder and Tinio, 2014).  Chen, Wu, and Wu (2011) learned that “Symmetric patterns are more appealing to human observers than asymmetric ones. . . . [and] preference can be accounted for by the complexity of the image.”   Existing research on symmetry is neatly summarized by Leder and Tinio (2014): “Symmetry is found in nature, symbol systems, and graphic depictions across different cultures and eras.  Even infants show preference for symmetry. . . . positive bias toward symmetry has been found using different stimuli. . . . the preference for stimuli has also been shown in aesthetic judgment of meaningless, abstract patterns.” Studies have specifically addressed links between symmetry and mood.  Pecchinenda and colleagues found that not only is visual symmetry preferred in multiple contexts including “the aesthetic appreciation of works of art,” it also induces “positive affect [mood]” (Pecchinenda, Bertamini, Makin, and Ruta, 2014). The research team observed, for example that “symmetric dot-patterns spontaneously elicit positive affect. . . . visual symmetry in novel, abstract patterns spontaneously engenders positive affect [mood].”  
• More complex (than medium) patterns increase the energy levels of viewers (Mahnke, 1996).  Higher energy levels may be desired in particular situations, for example, in exercise areas or amusement parks, and more visual complexity should be used accordingly, as needed.
• Ceylan, Dui, and Aytac worked with professional managers to identify places in which these managers felt they would be creative (2008). The participating managers rated photographs of 25 different offices on their "creativity potential."  Managers assessed the creativity potential of the places photographed by answering the question, “If you have a very special problem to solve and needed to generate a lot of new ideas where would you most likely choose to go?” All places shown were scored on a scale that ranged from least likely to be chosen to most likely to be chosen.  An analysis of the offices that were rated as having higher creativity potential indicated that “compared to offices with low creativity potential, offices with high creativity potential have lower complexity, more plants, bright lighting conditions, windows, cooler colors, and a computer.” The complexity of the offices found to be "most creative" are not stark, and they are also not cluttered with extraneous materials; they have moderate visual complexity.  

Clutter-Specific Research 

Cluttered spaces and scenes have high levels of visual complexity.  

• Clutter degrades cognitive performance. Renner (2020) succinctly presents Kastner’s important work on visual clutter. Renner quotes Kastner, who is a professor at Princeton, and reports on her work: “’Many of us aren’t good at processing clutter,’ says Kastner. ‘It can become overwhelming and make our brains do more work to complete simple tasks.’ The more conflicting stimuli we’re dealing with, the more our brain has to work to filter out what we need. When you take away this strain on our brains from competing objects, focusing becomes much easier. In 2011, Kastner found that people who cleaned up their homes or workspaces were able to focus better, and their productivity increased. Other research teams have confirmed that decreasing visual distractions can reduce cognitive load and free up working memory.”  
• Visual clutter in workplaces increases employee stress levels, thereby degrading performance and wellbeing: researchers (Roster and Ferrari, 2020) “hypothesized that workers whose jobs require them to deal with heavy volume of work at a rapid pace would be more likely to experience job strain (i.e., emotional exhaustion), which, in turn, depletes their energy and makes workers more likely to delay decisions.  Decisional procrastination (indecision) was expected to increase office clutter, which itself is a physical stressor.  Data . . . supported the hypotheses.” Clutter was described “as a collective body of physical objects, whether personal or work-related, that create disorganized and chaotic workspaces. . . . Viewing office clutter as ‘stress-generating’ corresponds to Vischer’s (2005, 2007) theoretical model of environmental comfort, which proposes that functionally uncomfortable workspaces draw energy out of workers that would otherwise be directed toward performing work tasks or addressing adverse environmental conditions.”   In short, “office clutter serves as a constant visual reminder of work left undone, making it more difficult to locate information quickly and potentially engendering feelings of guilt and embarrassment.”  
• Roster, Ferrari, and Jurkat confirmed that residential clutter reduces wellbeing (2016). “Clutter” was defined by the research team as “an overabundance of possessions that collectively create chaotic and disorderly living spaces.”  An online survey of adults living in the US and Canada determined that living in cluttered spaces reduces residents’ perceptions of their own wellbeing. Storage units with impossible-to-see-through doors, for example, can reduce perceived clutter. Study participants were asked if they’d be willing to answer survey questions after they visited the websites of professional organizers.  All methodologies and questions used were assessed, however, and found appropriate by a team of reviewers before the study was published.

SURFACE COLORS/PATTERNS

Surface colors/patterns have a significant effect on our professional performance and wellbeing, as discussed in detail in this article.

The colors used on surfaces and the light falling on those surfaces need to be coordinated.  Warm surface colors generally look best in warm light and cool surface colors in cooler light, for example.  More information on effectively utilizing light color and intensity to achieve particular cognitive, emotional, and physical objectives, is available here. 

Language spoken influences expectations and experiences related to colors and other sensory experiences, as discussed here.   

Colors used on surfaces often send silent messages to viewers.  The information conveyed varies by culture, as discussed here.  

Cognitive and Behavioral Effects of Surface Colors

Energize or Calm

Valdez and Mehrabian comprehensively examined how color hue, saturation, and brightness relate to viewer pleasure and energy level (1994). They define brightness or value as a color’s position on the black-to-white continuum and saturation or chroma as the purity of a color, with gray being more present in lower saturation colors (they are more gray-ish). Hue in the Valdez-Mehrabian terminology is the wavelength of light that characterizes a color. Hues are the names we give to sets of colors, such as greens, reds, and blues. 

Saturation and brightness influence emotional response to colors. In general, brighter and less saturated colors are more relaxing to view while more saturated and less bright ones are more energizing to look at (Valdez and Mehrabian, 1994).  Using the colors shown at the Wikipedia webpage on shades of green (https://en.wikipedia.org/wiki/Shades_of_green)  to illustrate this point: seeing the color celadon is relatively relaxing while looking at a color such as forest green is relatively energizing.

Suk and Irtel investigated emotional responses to colors, and their findings confirmed those of Valdez and Mehrabian (2010). So does research conducted by Palmer Schloss, Xu, and Prado-Leon (“Bach to the Blues, Our Emotions Match Music to Colors,” 2013).

Enhance Professional Performance

Research has shown there is a relationship between the sort of mental work being done and the best colors to use in the surrounding environment.  More cognitive challenging tasks should be done in calmer spaces and less challenging ones in more stimulating environments (Stone, 2003). For more information about optimal stimulation levels for various sorts of activities, read this article.  Working at a less challenging task in a calming environment seems to reduce performance levels, as employees seem to be below an optimal stimulation level in that situation. Performing a less mentally challenging task in an energizing environment optimizes performance because the stimulation from the environment counters the less challenging nature of the task. The reverse is found when a task that’s cognitively challenging is underway.

Biophilic design has a significant effect on human welfare, mentally and physically; biophilic design and its implications are discussed in this article.  Schertz and Berman (2019) reviewed published studies exploring the cognitive repercussions of being exposed to nature.  They determined that “exposure to a variety of natural stimuli (vs. urban stimuli) consistently improves working memory performance. . . . Overall, there is compelling evidence to support the advice of Thoreau and Murray to spend time in nature. Exposure to natural environments has been shown to improve performance on working memory, cognitive-flexibility, and attentional-control tasks. These results come from studies conducted using a variety of simulated environments (e.g., images, sounds, virtual reality) as well as real-world environmental exposure. . . . One potential mechanism that has emerged for these effects involves the perception of the low-level features of the environment. . . . low-level features include color properties—such as hue, saturation, and brightness (value)—as well as spatial properties—such as the density of straight and nonstraight edges and entropy. . . . Natural environments in general have more nonstraight edges, less color saturation, and less variability of hues.”

We don’t perform as well in offices that are achromatic (e.g., those that are primarily gray), as we do in ones that aren’t.  Ozturk, Yilmazer, and Ural (2012) determined that “chroma significantly affects performance and space appraisal. . . . performance scores measured significantly better in the room with the chromatic scheme than those in the room with the achromatic scheme.” In addition, “The office with the chromatic scheme was found to be more pleasant, attractive, satisfying and dynamic than the one with the achromatic scheme, whereas the achromatic scheme was thought to be more formal and harmonious.”  This study was carried out in a setting designed to replicate “an ordinary private office.”  Colors used in all test conditions were matched for value or lightness or brightness.

Red impairs analytical performance; after looking briefly at something colored red, people perform significantly more poorly on this sort of mental work (Elliot, Maier, Moller, Friedman, and Meinhardt, 2007). After “seeing red” people also seem to avoid tasks at which they might fail. People who have looked at something red are significantly more likely to choose, for instance, to answer easier questions instead of harder questions. Elliot and research team hypothesize that these effects might be caused by learned associations between red and failure. For example, red pens are often used to mark school papers. The link between exposure to red and Elliot’s team’s results seems to be unconscious. Participants in the reported study who were exposed to red by the researchers saw their participant number marked in red on their test form before a competence evaluating test began or the name of the test appeared in a red block on the inner title page of their test booklet. In the course of the set of experiments reported, four different shades of red were used. Each shade was the saturated, not bright sort of red that might be associated with a marking pen. The material uncovered by Elliott and colleagues supports work done by researchers such as Kuller, Mikellides and Janssens linking seeing reds with higher energy levels (2009).  At higher energy levels, performance on tasks requiring concentration is impaired.

Maier, Hill, Elliot, and Barton (2015), after reviewing existing scientific findings, share that “The inimical [negative] effect of red [on intellectual performance] is probably most likely to emerge for moderately challenging tasks, for tasks requiring cognitive flexibility and mental manipulation, and under conditions in which cognitive resources are taxed (e.g., when time constraints exert pressure, when ability evaluation or intelligence is made salient).  In addition, it is possible that only certain variants of red, (those most clearly resembling that of danger signs or warning signals) are influential in performance contexts; a light (pinkish) red or a red with a moderate to low level of saturation may have minimal impact.”

Facilitate Creative Thinking

A team led by Lichtenfeld linked seeing the color green and enhanced creative performance (2012).  In a rigorous set of experiments that eliminated saturation and brightness as potential explanations of the effects found, this team “demonstrated that a brief glimpse of green prior to a creativity task enhances creative performance. . . . A brief glimpse of green prior to engaging in a creativity task facilitates the creativity (but not overall amount) of response output.” When these researchers say “brief” they do indeed mean “quick;” in one test condition, study participants were exposed to the color green for approximately two seconds. A specific shade of green does not seem to be required for these effects on thinking to occur.

Studente, Seppala and Sadowska studied how seeing live plants, nature, and the color green influences creative thinking (2016).  In their experiment “Three groups [of participants] were used; one group in a classroom surrounded by plants and view to natural settings [creativity task presented on white paper], one with no views to nature but who completed the task on green paper, the third, with no plants present and no views to nature [creativity task on white paper].”   This work confirmed that of Lichtenfeld and colleagues indicating that seeing the surface color green enhanced creativity.

Encourage Pleasant Interactions with Other People

Choi, Chang, Lee, and Chang investigated how color can influence assessments (2016).  They found via “experiments and field surveys in the USA and South Korea. . . .  that an anonymous person against a warm color background (vs. neutral and cold color background) is perceived to be one with warmer personality.”  

Zanjani and colleagues investigated responses to video walkthroughs of different homes, ones with either warm- or cool-colored spaces (2016).  The investigators share that “The ‘warm’ virtual walkthroughs were chosen to be causal and expressive with yellow or red-centered color schemes. The ‘cool’ spaces were characterized by a high-tech, futuristic, austere, and geometric design with a blue-centered color scheme.”  Images included in the published paper showed residential spaces that might be present in any Western home. Study participants found warm area walkthroughs to be quite different experiences than cool area walkthroughs: “’Warm’ walkthroughs, in comparison to ‘cool’ ones, were judged to be significantly warmer, familiar, relaxed, secure, private, and evoked more personal memories. These characteristics were previously shown to be positive features of homes. . . .  ‘warm’ walkthroughs provided a greater sense of security and privacy that made viewers feel more relaxed.”

Influence Perceptions of Power

The relative warmth/coolness of the colors we see influences perceptions of power and competence (Dubois and Mehta, 2012).  People seen against warm colors (for example, yellow) seem less powerful than individuals pictured against cool-colored (for example, light blue) ones.  The same effects were found for organizations whose logos (all logos were presented in shades of gray) were seen against cool or warm backgrounds.  Organizations whose logos were seen against a cool background were also perceived to be more competent than those whose logos were viewed against warm backgrounds.  Organizations whose logos were shown against warm-colored backgrounds were judged to be psychologically warmer than those whose logos were presented against cool-colored backgrounds. People in cooler colored places also seem to feel more powerful than those in warmer colored ones.  Colors viewed were matched on saturation and brightness levels. 

Optimize Physical Performance

Elliot and Aarts (2011) compared the outcomes of looking at reds, blues and grays that were equally saturated and bright and report that “viewing red enhances strength output on simple motor tasks of a brief duration, suggesting that red may be beneficial for activities such as athletic events requiring short bursts of brute force (e.g., weightlifting) . . .  [however] viewing red is likely to be inimical [detrimental] for skill-based motor tasks (e.g., hitting a tennis ball) and analytical tasks (e.g., solving anagrams) requiring concentration, mental manipulation, and/or the coordination of multiple systems.”

Briki and colleagues had people pedal stationary bicycles while in predominantly red, green, or gray environments (2015).  The red and green shades used had equal levels of saturation and brightness. The researchers “aimed to compare the effects of perception of red and green environments on physical (performance and heart rate) and psychological (perceived effort, anxiety and enjoyment) parameters during cycling trials. . . .  Ten cyclists [rode] 7-minute trials on home trainers” while experiencing the various colored spaces.  The investigators found that “covered distance . . . and heart rate . . . were lower in the red environment than in the gray and green environments. Enjoyment was higher in the green environment than in the red environment. . . The colored environments did not influence perceived effort and anxiety.”  The researchers report that the burst of physical power that results from viewing red seems to be coupled with “deleterious [negative] consequences on motor performance over an extended period of time.”

Draw People to a Particular Location

Research has shown that people are drawn toward warm colors, in general (Bellizzi, Crowley, and Hasty, 1983).  People trying to lead people through a space can use red and other warm colors to do so.

Perceptual Effects

Speed Up or Slow Passage of Time

Time is perceived to pass more slowly in warm-colored spaces than ones that feature cool colors (Baker and Cameron, 1996).  Waiting rooms and similar spaces should definitely be painted in cool colors.

Make a Space Seem to Be the “Right” Temperature

The colors used in a space can have a significant influence on the perceived temperature in it, with cool colors reducing the apparent temperature and warm colors increasing it (Mehta, Chae, Zhu, and Soman, 2012).

Ho reports that we expect warm colored surfaces to be hotter than cool colored ones (2015).

Signal Danger/Safety

Researchers have determined that the color red communicates danger. As Pravossoudovitch and team (2014) describe, there is “an implicit association between red and danger. Our findings confirm the wisdom of using red to communicate danger in systematic signal systems, and suggest that red may be used more broadly in other communication contexts to efficiently convey danger-relevant information.”

A research team lead by Siu indicates that children and adults have similar associations to the color red (2017).  This research is important because as Siu and colleagues indicate “Color has been identified as a key consideration in ergonomics.  Color conveys messages and is an important element in safety signs, as it provides extra information to users.”  The researchers report that while previous studies have shown that adults link red with “hazard/hazardous,” their research indicates that children 7 to 11 years old associate red with “don’t.” This information means that the color red is a good choice for warning signage, regardless of viewer age.

What colors are best for emergency signage? A research team lead by Kinateder (2018) determined that when study “Participants were immersed in a virtual room with two doors (left and right), and an illuminated sign with different colored vertical bars above each door. . . . On each trial, a fire alarm sounded, and participants walked to the door that they thought was the exit. . . .  Participants predominantly walked toward green signs, even though the exit signs in the local environment—including the building where the experiment took place—were red. However, in a post-experiment survey, most participants reported that exit signs should be red. The results demonstrated a dissociation between the way observers thought they would behave in emergency situations (red = exit) and the way they did behave in simulated emergencies (green = exit). These findings have implications for the design of evacuation systems.”

Objects that are yellow have a sort of “visual priority.”  Hu, Rosa, and Anderson (2019) found that when they “examined the visual priority of yellow relative to luminance matched colors at opposing ends of the wavelength spectrum (i.e., red and blue), using a temporal order judgment task, between color pairs. Despite being matched in arousal, when yellow and blue were pitted against each other, yellow was consistently seen as occurring first, even when objectively appearing second at short stimulus onset asynchronies. Despite being matched in valence, yellow again showed a larger temporal priority when it was pitted against red. . . . These results support that yellow is a safety color, having a temporal advantage.”

Colors Used Together, in Patterns

Pattern Fundamentals

Research on how symmetry, line, shapes, balance, and other design fundamentals influence responses to patterns/design elements viewed is discussed in this article.   For more information on visual patterns generally, read this article.   

For information specifically related to fractal patterns, review this article. 

Material on using wood grain effectively is discussed in this article. 

Colors Used Together

As Ou (2015) notes some color combinations seem more harmonious or pleasing than others: “Colors having the same hue tend to appear harmonious. . . . Colors having the same chroma [saturation] tend to appear harmonious. . . .Small lightness variations between the constituent colors in a color pair may reduce the harmony of that pair. . . . The higher the lightness value of each constituent color in a color pair, the more likely it is that this pair will appear harmonious.”  Also, colors that differ only in lightness are harmonious combinations.   However, “If the lightness difference increases, then the color-harmony score also increases. . . . Highest color-harmony scores are produced by colors having small chroma differences.  Color combinations of a high chroma difference produce lower color-harmony scores.. . . Similar hues produce high color harmony scores.”  In other words, combinations of colors that are matched/similar in hue or saturation are best, while small lightness differences can reduce the pleasingness of combinations, but color lightness among sets of colors is desirable and colors that differ only in lightness are harmonious.  

Examples of Additional Research with Visual Patterns   

• Rodemann learned that “The larger the scale of the design, the smaller the group of people the pattern appeals to” (1999). 
• Patterns on walls that are smaller in scale tend to increase the apparent size of a space (Mahnke, 1996.)
• Wilkens and team (2018) determined that some patterns, in particular some striped ones, are more likely to lead to visual stress than others.  The researchers “focus on a phenomenon known as ‘visual stress’ induced by repetitive, geometric patterns around us. Geometric patterns, particularly patterns of stripes, can be uncomfortable to look at (Wilkins et al., 1984). . . . we do not want to imply that stripes should be avoided at all costs. Using stripes to accentuate areas of danger might be highly beneficial. . . . The negative impact of such patterns on the visual system can be reduced by using thin grouting that contrasts little with the surround (thereby reducing the energy in the pattern), or by breaking the pattern up through mixing of different-sized tiles or bricks.. . . stripes that close- up are widely spaced and thus do not induce discomfort can do so when looked at from further away. . . . Avoid repetitive elements that are as wide as the space between them, because evenly-spaced stripes are the most aversive.” Additional tips on designing to minimize visual stress are available in the article by Wilkins and colleagues, which can be downloaded without charge at https://www1.essex.ac.uk/psychology/overlays/2018-246.pdf

PRIORITIES 6 – 10

There are five additional sensory priorities that need to be top-of-mind among workplace designers and managers. 

• Lighting (artificial and natural) As discussed in this article, both the artificial and natural light that individuals and groups experience as they work has a dramatic effect on cognitive performance and how well people cooperate/work together/get along.  Generally, warmer light is best for relaxing (particularly if it’s dimmer) and creative thinking while cooler, higher intensity light is best for concentration.  Warmer light is most powerful when it’s closer to the ground (for example, delivered by bulbs in tabletop or floor lamps) while cooler light effects are more pronounced when the light is overhead.
• Sightlines What we can see as we work influences how comfortable or stressed we feel in a space, which has far-reaching consequences for our physical health as well as how effectively our brains can process information, analytically and emotionally.  For example, when other people can see what we’re doing, alone or in a group, we’re likely to modify our behavior to make a positive impression on those observers, and those behavior modifications often degrade our professional performance.  For more information on sightline implications and management, read this article. 
• Furniture design (forms that promote positive conversations and comfort, for example) The form and arrangement of tables, chairs, and other pieces of furniture influence whether we speak to others, how we treat group members, and generally how effectively and efficiently we execute whatever we’re trying to accomplish, for instance.  For related information, read this article, for example. 
• Biophilic design (elements not already noted)  Things always go better for humans when they’re in spaces that recognize and respect the conditions in place in the spaces where we had positive experiences as a young species—in other words, ones that are biophilicly designed.  Multiple aspects of biophilic design were discussed during the earlier sections of this report but for more on this topic, read this article.  
• Tactile experiences Regularly we don’t actively consider the information that flows into our brains through sensors on our skin, but we should, because tactile experiences have an important effect on how well we work and whether we have pleasant experiences as we do.  For more information on designing positive tactile experiences, read this article. 

No Design Element Acts Alone

Sensory experiences are usually discussed one-by-one, but they influence what goes on in our heads as holistic sets we experience simultaneously. To learn more about how sensory experiences combine in our brains to ultimately affect how we think and behave, read this article.

TakeAway

When lack of available resources (time, budget, expertise, or otherwise) prevent all potential high-impact sensory considerations from being acted upon, use this prioritized list (more significant higher on the list) to organize your efforts: 

• Ventilation/Air quality/Scents
• Acoustical conditions
• Opportunities for cognitive refreshment
• Visual complexity
• Surface colors/patterns
• Lighting (artificial and natural)
• Sightlines
• Furniture design (forms that promote positive conversations and comfort, for example)
• Biophilic design (elements not already listed)
• Tactile experiences 

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