Keywords: N.A.
The importance of urban parks has been established in many studies over the last years. Next to
environmental benefits, like improved air quality, biodiversity, and rain water storage, urban parks have
benefits for the health and wellbeing of the people visiting them. They increase physical activity, reduce
obesity, and decrease stress and mental fatigue for people living in proximity (Konijnendijk et al., 2013).
As cities continue to grow and densify (United Nations, 2018), urban parks are increasingly important
to expose an expanding number of people to a healthy environment.
There are many studies that have measured the reduction of mental fatigue and stress in natural
environments (Canin, 1991; Cimprich, 1990; Grahn, & Stigsdotter, 2003; Hausmann, Hug, & Seeland,
2007). Subsequently, there also exists a large body of research into why natural environments have
these effects on stress and mental fatigue (Kaplan, 2004). This largely originated from research into
preference by, among others, Ulrich (1983). Ulrich reviewed the affective reactions associated with the
visual perception of natural environments. He theorized that pre-cognitive affective responses to an
environment served adaptive needs, meaning that those who had a favorable, adaptive response to
environments with beneficial characteristics for wellbeing were favored in evolution. This would
explain the positive affective response to unthreatening natural content, where one would find elements
like water, food or shelter. He stated that an attractive natural view might induce feelings of
pleasantness, hold interest, block or reduce stressful thoughts and therefore induce psychophysiological
restoration. This theory was later called the psycho-evolutionary Stress Reduction Theory (SRT)
(Ulrich, 1983).
Another theory explaining the beneficial effects of nature on stress and mental fatigue is Attention
Restoration Theory (ART) of Kaplan (1995). Urban lifestyles generally impose a big demand on
cognitive resources (Kaplan & Berman, 2010). This translates to a prolonged use of directed attention,
which can lead to cognitive depletion and results in increased mental fatigue and stress. According to
ART, restoration derives from recovery of directed attention fatigue. In order for recovery of directed
attention to take place, involuntary attention should be used. Involuntary attention is said to not require
effort, and thus is resistant to fatigue. While an individual is using involuntary attention, directed
attention should be able to restore. Natural environments have been shown to generally require
involuntary attention and therefore are potentially restorative places (Kaplan, 1995).
Kaplan (1995) has tried to integrate SRT and ART and came up with a framework where both
approaches fit in. The framework consists of three possible pathways or patterns that all eventually
result in impaired performance. Overall, it suggests that a resource decline can lead to a stress response
and a stress response can lead to a resource decline. Kaplan’s integrated framework points to the
existence of two distinct, but interacting, sources of restorative experiences.
However, there is a factor that might constrain the restorative potential of natural environments;
perceived safety. Many studies have shown that urban parks are often perceived as unsafe (e.g. Lis et
al. 2019; Lis et al. 2021; Lis & Iwankowski, 2021a; Türkseven Dogrusoy & Zengel, 2017). These effects
are mostly attributed to two characteristics, prospect and refuge, which refer to Appleton’s prospectrefuge theory (1975). This theory states that the possibility to see (prospect) and not being seen (refuge)
is basic to many biological needs. According to Appleton, an environment elicits preference if it suffices
to accommodate enough prospect and refuge. However, the term refuge was found to be somewhat
ambiguous, as it can be desirable when needed, but it can also become a source of danger when attackers
hide in that same space. This is one of the reasons Fisher and Nasar (1992), and Nasar and Jones (1997)
enhanced the prospect-refuge theory, adjusting and adding to the relevant environment characteristics
that influence the perception of an environment. They argued that it was better to use the characteristics
prospect, concealment and entrapment, rather than prospect and refuge. This proposed framework
7
asserts that the total of these environmental qualities are used by people to infer the safety of an
environment. There are several manners in which an urban park can manipulate these environmental
characteristics, but some that are often investigated are altering the amount of vegetation and lighting.
Adding vegetation results in less permeability, and decreases the level of prospect and increases the
level of concealment and entrapment. Meanwhile, decreasing the illumination levels should reduce
prospect and increase the opportunity of concealment and entrapment at nighttime. The resulting
environments might be perceived as threatening and would require directed attention, which makes
them less likely to feel restorative according to SRT and ART. On the other hand, it could be argued
that more vegetation, and thus less permeability, leads to more natural environments, which would
increase the restorative potential.
Although a large body of research into the effects of permeability and lighting on perceived safety
exists, there is a lack of studies investigating the subsequent influence of perceived safety on perceived
restorativeness in urban parks at nighttime. Thus, despite the theoretical influence of perceived safety
on perceived restorativeness that is discussed in both SRT and ART, there is not much empirical
evidence to be found on the subject. In addition, the influence of lighting, and the combination of
lighting and permeability on perceived restorativeness seems an underdeveloped topic altogether. The
current study will attempt to gain more insight in what is happening when manipulating the permeability
and lighting levels of urban parks at nighttime. This results in the following three research questions
(RQ):
RQ1: To what extent do light and permeability above and below the horizon line levels influence
perceived safety?
RQ2: To what extent do light and permeability above and below the horizon line levels influence
perceived restorativeness?
RQ3: To what extent does perceived safety influence perceived restorativeness?
To be able to understand the effects at work in urban parks at nighttime, it is important to first take a
closer look into these restoration theories in all their aspects. In the next part of this report the theories
and involved factors will we explained in greater extend, followed by the research aim and method of
the experiment. The performed experiment consisted of a survey with several different videos where
the permeability and lighting levels were manipulated. After watching the videos, participants were
asked to answer rating scale questions about either perceived safety or perceived restorativeness. The
data was then analyzed and the results discussed. At the end of the report a conclusion of the study is
given.