Motivation and emotion/Book/2020/Stress reduction theory

Overview

 * 1) Stress and its effects on the human mind and body.
 * 2) Understanding stress reduction theory (SRT) and how it helps to minimise the symptoms of stress.
 * 3) Case study- stress reduction with the presence of plants in a hospital environment (Dijkstra et al., 2007)
 * 4) The effects of natural elements on human emotional and physiological responses.

Focus questions:
 * What is stress?
 * What is stress reduction theory (SRT) and how does it work?
 * Can nature truly reduce stress?

Abbreviations
CNS- central nervous system.

CORT- cortisol, a hormone secreted by the adrenal gland during times of stress.

SRT- stress reduction theory.

WM- working memory.

ARS- attention restoration theory.

PTT- pulse transit time, a non invasive measure of time taken for pulse to travel between two arterial points.

TSST- trier social stress test, a test which reliably induces stress in participants, used primarily for stress related experiments.

What is stress?
Stress is considered to be a physiological response of an organism, where defence mechanisms are evoked and activated in order to confront a situation that is perceived as threatening, or of increased demand (Scott, 2011; Genco et al., 1999). Stress, of some magnitude, occurs in every day life, and almost everyone has experienced some form of stress at least once before. According to American psychologist Karl Albrecht, there are four types of stressors; Time stress, anticipatory stress, situational stress, and encounter stress (Albrecht, 1979).

Time stress

Time stress is as it sounds- it is stress experienced when you worry about time, or lack there of (Albrecht, 1979). For example, rushing to avoid being late, or worrying about a deadline.

Anticipatory stress

This type of stress addresses the feelings of worry that are related concern the future., whether it be a specific event, such as an upcoming presentation, or it can be more vague and undefined, such as a general sense of concern for the future.

Situational stress

This occurs when you are in an uncontrollable situation, one that may evoke a fear of some sort, but most commonly in our day to day lives involves conflict, or a loss of status. something that is experienced when a job is lost, or embarrassing yourself in front of a group.

Encounter stress

This stress is centred on the people around us. Stress of this type is experienced when you worry about interacting with a certain person or group of people, such as a crush or someone you are afraid of.

Various situations tend to elicit different patterns of stress responses, or types of stress responses. However, there are also individual differences in stress responses to the same situation. This tendency to exhibit a certain pattern or type of stress response across a variety of stressors is referred to as ‘response stereotypy’ (Lacey & Lacey, 1958). Thus, across a multitude of potential situations, some individuals tend to show stress responses associated with active coping techniques, whereas others tend to display stress responses that are more so associated with aversive vigilance (Kasperowicz et al., 1990; Llabre et al., 1998). Active coping mechanisms usually involve awareness of the stressor and a conscious attempt to reduce its affects. For example, when a student has an upcoming exam, they are likely to experience symptoms of stress. To avoid such stress through means of active coping, the student (knowing they are about to be stressed) would begin studying early, and prepare themselves as much as possible, and in turn reduce stress. On the other hand, a student who takes an aversive approach to stress, will attempt to avoid the stress, which may result in more stress.

Sources of stress
The source of stress varies from individual to individual, as does the degree of it s affects. As many types of stress seem common among majority of individuals, a questionnaire was conducted. This contained several of what were deemed the most common sources of stress: noise, school or work, social conflicts, arguments, time pressure, and travel. The most common type of response for another possible source of stress was health concerns, this is the value that can be seen in the column labelled 'Other sources'. Almost half (43.3%) of the participants marked or added at least one source of stress. The percentage of each stress source is shown in the table below (Table 1.).

Table 1.

Percentage of survey respondents exposed to various sources of stress prior to visiting green location (N=164). Source: https://www.sciencedirect.com/science/article/pii/S1618866707000623 (Hansmann et al., 2007)

Prevalence


As many people have experienced stress at least once before, it is undoubtable a very prevalent and often underestimated experience for the mind and the body. In 2000, the statistical report of the British Health and Safety Executive (HSE) that there had been a 30% increase in occupational stress levels within the five years between 1990 and 1995. Several years later, a study had highlighted the role of stress in the shaping of sickness patterns, and in 2009, the HSE estimated that an annual 13.5 million working days were lost due to employee stress (Jackson M., 2015). Today, 450 million people worldwide are affected by mental health issues (WHO). For example, a recent study has concluded that the global prevalence of stress among college students (mixed gender) was approximately 80%.

Why do we want to reduce stress? The effects on our health.
Urban living in particular has been known to, quite frankly, give the brain a 'workout', which alters the way we experience and cope with stress (Legg; Fraga., 2019). Stress reduction theory solidifies such a notion by drawing attention to the effects of natural elements. Stress begins in the brain, and has effects on both the brain and the rest of the body. Consistent exposure to stressors can lead to chronic stress which can promote and exacerbate pathophysiology in the same way that the systems are disrupted. The weight and implications of stress along with the accompanying changes in personal behaviours, otherwise referred to as "lifestyle" (e.g. changes in food consumption, poor sleep quality) is named allostatic overload (McEwan., 2007). Brain regions such as the prefrontal cortex, hippocampus, and amygdala respond to instances of stress, acute or chronic, and display signs of changes in their morphology and chemistry. These changes are still reversible if the stress period lasts for several weeks, however, in instances of prolonged stress the effects on the brain and associated mechanisms may be irreversible (McEwan et al., 2007). Stress also affects cognitive performance. Acute, and constant stress in particular, have well documented and detrimental effects on cognitive processes such as working memory (WM).

The hormone cortisol (CORT), also known as 'the stress hormone', is produced in the adrenal cortex and is responsible for many of the bodies stress responses. It increases the bodies heart rate, fast thoughts, and blood pressure (Lee et al., 2015). This leads to the commonly experienced symptoms we associate with stress. Stress is associated with many harmful effects on the body, and has been understood to play a role in the development of certain illnesses and diseases, and also affects the way in which individuals cope with illness and disease (Yaribeygi et al., 2017).

Quiz
Choose the correct answers and then press the "Submit" button: {A reduction in stress can help with which of the following? - Emotional wellbeing - Physiological health - Increasing your focus - Overall satisfaction with life + All of the above
 * type=""}

{What are Albrecht's four types of stress?} - Situational stress, appearance stress, time stress, life stress +Time stress, anticipatory stress, situational stress, and encounter stress - Encounter stress, anticipatory stress, social stress, and time stress

A brief history
A research psychologist, R. Ulrich developed SRT, in 1991. His theory was constructed based on a number of studies situated in a hospital environment with the aim of explaining our emotional and physiological responses to the presence of natural elements (Ulrich et al., 1991). In his 1991 journal article, he discovered that between the natural and urban environment, there were indeed differences in cardiac responses, suggesting that attention/intake was higher during exposure to the natural environment.

The experiment conducted by Ulrich and colleagues started with the intention to investigate the following hypotheses:


 * 1) if individuals are stressed, an encounter with most unthreatening environments will have a stress reducing, or restorative influence.
 * 2) many urban environments will hamper such recuperation
 * 3) emotional, attentional, and physiological aspects of stress reducing influences of nature are based on the psycho-evolutionary theory, in other words, are grounded in evolution.

To investigate the hypotheses, 120 subjects were acquired. First, they viewed a stressful movie, and then were exposed to video tapes involving colour and/or sound of one of six different natural and urban settings. Data regarding stress recovery during these environmental presentations was obtained through measures such as self-reported ratings on affective states, and a series of physiological measures: heart rate, muscle tension, skin conductance, and pulse transit time (PTT), correlating with blood pressure.

The findings from both the psychological and verbal measures indicated that the individual's recovery was significantly faster and more complete when the subject was exposed to natural rather than urban environments. The pattern of such findings raised many possibilities for the future of psychological science and the health and wellbeing of humans. Responses to nature had displayed a salient parasympathetic nervous system component, which was lacking any evidence at all regarding the involvement in responses to the urban setting.

Key points
The key goals of many psychological research papers and journal articles is to ultimately increase human happiness. The relationship between nature and happiness most commonly depends on how happiness is defined and measured. In wellbeing research, happiness is more or less synonymous with general life satisfaction (Della Fave et al., 2016). However, for the purpose of this chapter, happiness and wellbeing will be addressed more narrowly, and in terms of minimal stress.

As discussed above, stress levels are on the rise, and thus, such inclusions of natural elements and the relevant emotional theories/research must be employed to help combat the negative symptoms of stress evoked by urban life, as well as other stressors. If such strategies are employed, we can hopefully minimise the impact of stressors, as well as minimise the number of those who have anxiety or experience high levels of stress regularly.

SRT proposes that the mere presence of such natural places will produce an affective, subconscious, and measurable reaction within minutes. Generally, in urban areas, the higher the level of vegetation, the greater the stress reduction (Jiang et al., 2014). There is a growing body of research and literature showing that the natural environment has positive effects on individuals' health and wellbeing while modern cities have negative impacts on human health with the combination of air pollution, noise, and a lack of greenery. A literature review linking the natural environment and health effects was conducted by Tan and colleague in 2006. The results included Kaplan and Kaplan's attention restoration theory (ARS) and Ulrich's SRT, and indicated other relevant evidence. The study indicated that for those living in Mianying City, China, there was a high level of stress relief associated with visiting one of three urban parks and green spaces in the city. This then showed support of Ulrich's theory by displaying signs of stress recovery and attention restoration.

Quiz questions
Choose the correct answers and then press the "Submit" button: {R. Ulrich developed his theory of stress reduction based on a notable number of studies carried out in a(n) ___? - School + Hospital - Office building - Gym - Park
 * type=""}

{Stress reduction theory aims to explain our emotional and physiological responses in the presence of (a) ___?} - Nothing - Friends - Stressful environment + Natural elements - Work environment

The restorative environment
For centuries, philosophers, artists and pets have suggested that in order for people to reduce their levels of stress, people must escape to nature. Emerson, Thoreau, and Whitman wrote about the sense of peace and tranquility that comes hand in hand with the act of being in a forrest, near a lake, or any other natural place. More recently, however, scientists have begun to prove that exposure to nature is related to a significant increase in ones capacity to deal with the difficulties faced in life (Kuo, 2001). To be put more simply. increasing tranquility, peacefulness, and relaxation, decreases the physiological indicators of stress (Ulrich, 1993; Parsons et al., 1996; Change et al,m 2005).

Currently, over than 50% of the global population live in urban cities, this statistic is forecasted to rise to over 70% by the year 2050. However, numerous studies have indeed revealed that cities and city life is associated with an increase in mental health risk, compared to rural living (Gruebner et al., 2017). In Scotland, more urban living environments are associated with higher rates of prescriptions targeting psychotropic medications for anxiety, depression and psychosis (McKenzie et al., 2013).



Empirically determined effects of the natural environment
A common question regarding stress reduction theory is whether or not incorporating plants into the home environment going to be enough, or do we need to escape urban environments to nature and nature alone. As the study conducted by Ulrich and colleagues in 1991 solidifies the notion that being in a natural environment is suffice to have significant effects on the mind and body, the following study focusses on the effects of inclusions of smaller natural elements within a non-natural setting. In 2007, Dijkstra and colleagues conducted an experiment on the stress reducing effects of plants in the indoor environment. This was based on the findings of Ulrich (1991/1993), attempting to empirically solidify his theory of stress reduction and prove its effects on the human psyche. However, the goal of this study was to understand the effects on a smaller scale that is achievable in everyday urban life.

Case Study

Objective

In the healthcare environment, natural elements have been shown to hold potential stress-reducing properties. To further understand the effects and the mechanisms underlying the stress reducing effects that nature possesses, the following study investigates whether the stress-reducing effects of indoor plants occur because such environments are perceived as more attractive. The study was conducted from march to may in 2007, in the Netherlands.

Method

The study used a between subjects experimental design, in which there were 77 participants. The participants were presented with a scenario describing hospitalisation. Subsequently, participants were exposed to a photo of a hospital room. The photo either included indoor plants or a painting of an urban environment on the wall (control condition). After viewing the photographs, perceived stress and the perceived attractiveness of the hospital room were measured.

Results

Those who were exposed to the hospital room with indoor plants reported less stress than those in the control condition. A meditation analysis confirmed that indoor plants in a hospital room did indeed reduce feelings of stress for the individuals. This was deemed to be due to the perceived attractiveness of the room.

Conclusion

This study confirmed that natural elements in the built healthcare environment have stress-reducing properties, even if it is just a photograph or painting. It also illuminates one of the underlying mechanisms causing this stress-reduction – the perceived attractiveness of nature.

Furthermore, to make this theory more applicable to everyday life, the effects of indoor plants within the home environment were examined, and deemed successful. More recently, the use of environmental simulations on on TV screens in blood donor stress has also been evaluated and shown effective in reducing the stress of those about to give blood (Ulrich et al., 2003)

Evolutionary perspective
Ulrich's SRT is a key framework in making clear the reasons behind why contact with nature may foster a reduction in stress (Bratman et al., 2012; Ulrich et al., 1991: Jiang et al., 2014). In 1991, Ulrich and colleagues postulated that landscapes which contained vegetation, water, and visual complexity would have aided the survival of the human race for thousands of years. The basis for this is that in these natural settings, our ancestors may have sought food, predators, resources, or other humans, all of which were necessary to be seen for survival purposes. Thus, it has shaped our species and should help reduce the modern day psychological stress of humans.

Wilson (1984) posits that humans have an inborn tendency to focus on and affiliate with other living things (Wilson, 1984). This was the basis for a theory termed the biophelia hypothesis, devised by Kellert and Wilson. This theory described the innate attraction to life and lifelike processes can be understood through an evolutionary perspective (Lipsey et al.,1993). As humans have spent almost all of our evolutionary history being part of the natural environment, and have only relatively recently migrated to urban living, this identification, attraction,and need to connect to nature is to remain a key part of modern psychology (Kellert and Wilson, 1993). Furthermore, it would have been evolutionarily advantageous for human ancestors to be connected with nature, as it would aid in survival, along with thriving in the relevant environment. Thus, those who were more connected to nature would would have significant evolutionary advantage over those who were less connected with nature. Ulrich (1993) evaluated such concepts, and has concluded that through our interaction with nature, and the preparedness to development phobias related to persistent environmentally related threats (biophobia), we have evolved positive responses to the natural world (Ulrich, 1993). Evolutionary psychology more generally proposes that modern environments are not most favourably suited to minds, such as the minds of humans, that evolved in different- more natural- environments (Barkow et al., 1992; Buss, 2000).

The dose-response curve
The dose response curve refers to the level of nature exposure required for a significant change in level of stress. Although it is well understood that exposure to nearby nature can help reduce stress in individuals, the shape of the dose-response curve remains unclear. To establish the shape of this dose-response curve and to understand the ideal dose for the ideal outcome, Jiang and colleagues in 2014 recruited 160 participants for a laboratory experiment. Participants were asked to engage in the Trier social stress test (TSST) to induce psychological stress, an were then randomly assigned to view one of ten 3-D videos of neighbourhood streets, each of which were six minutes long. Each video varied in its visual density of tree cover, which ranged from 1.7% to approximately 62.0%. The stress reactions were then measured by assessing the participant's salivary cortisol levels and skin conductance levels. The results displayed a clear discrepancy between men and women. Women were found to show no relationship between the variation in densities of tree cover and stress recover. It was seemingly due to the fact that merely the presence of a natural element was sufficient. On the other hand, the male dose-response curve appeared to be an inverted-U shape: as tree cover density increased from 1.7% to 24%, there was an increase in stress recovery. Beyond this 27%, and up to 34%, there was no additional variation in rate of recovery. However tree densities above 34% were associated with a slower rate of recovery. From this, the dose-response curve was seen to be mathematically predictable. A quadratic regression using tree cover density as the independent variable and a summary stress index as the dependent variable substantiated the following [R2 = .22, F (2, 68) = 9.70, p < .001]. The implications of this experiment on our understanding of the impacts of nearby nature, link very closely with the future practices of areas such as planning and landscape architecture (Jiang et al., 2014). And thus, including such ideal levels of greenery in every day aspects of life, dependant on gender, can be beneficial for the reduction and minimisation of stress.

Table 2.

Comparison of salivary cortisol level (μg/dL) and skin conductance level (amplitude, percent of value) before and after participants were exposed to the same laboratory controlled TSST. Source: https://www.sciencedirect.com/science/article/pii/S0169204614001832 (Jiang et al., 2014)

Conclusion
Stress is a physiological response that almost each and every one of us experience, and it is on the rise. the effects of acute or chronic stress on an individual's health and wellbeing can potentially be both long lasting, and detrimental. There are several key types of stress, as proposed by Albrecht (1979): time stress, anticipatory stress, encounter stress, and situational stress. There appear to be two ways for an individual to approach such stress; active coping and aversive vigilance. However, a study conducted by Dijkstra and colleagues showed that stress, and its relevant affects depend on more than just the individual, as the aesthetic of plants, or the presence of natural elements, is enough to effectively reduce the mental and physiological responses. However, gender differences were noted. Stress reduction theory, devised by R. Ulrich in 1991 was the basis for this scientific movement, as Ulrich suggests and empirically demonstrates that nature alleviates symptoms of stress within minutes. As the theory is well grounded in our ancestral history and in modern scientific research, the prospects for it to aid those experiencing stress in everyday life, whether in a rural or urban space, are promising. Due to the fact that stress levels are on the rise and many individuals are experiencing it and all of its symptoms, it has become a global challenge, and the need for a psychological method of stress reduction is of increasing importance.