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The Influence of the Environment on
Directed Attention, Blood Pressure and
Heart Rate—An Experimental Study
Using a Relaxation Intervention
Eva Sahlina, Agneta Lindegårdb, Emina Hadzibajramovicb, Patrik
Grahna, Josefa Vega Matuszczykc & Gunnar Ahlborg Jr.b
a Department of Work Science, Business Economics and
Environmental Psychology, Swedish University of Agricultural
Sciences, Alnarp, Sweden
b Region Västra Götaland, Institute of Stress Medicine,
Gothenburg, Sweden
c Department of Social and Behavioural Studies, Unit of
Psychology and Organizational Studies, University West,
Trollhättan, Sweden
Published online: 22 Dec 2014.
To cite this article: Eva Sahlin, Agneta Lindegård, Emina Hadzibajramovic, Patrik Grahn, Josefa
Vega Matuszczyk & Gunnar Ahlborg Jr. (2014): The Influence of the Environment on Directed
Attention, Blood Pressure and Heart Rate—An Experimental Study Using a Relaxation Intervention,
Landscape Research, DOI: 10.1080/01426397.2014.982079
To link to this article: http://dx.doi.org/10.1080/01426397.2014.982079
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The Influence of the Environment on
Directed Attention, Blood Pressure and
Heart Rate—An Experimental Study Using
a Relaxation Intervention
EVA SAHLIN*, AGNETA LINDEGÅRD**,
EMINA HADZIBAJRAMOVIC**, PATRIK GRAHN*,
JOSEFA VEGA MATUSZCZYK*** & GUNNAR AHLBORG Jr.**
*Department of Work Science, Business Economics and Environmental Psychology, Swedish University of
Agricultural Sciences, Alnarp, Sweden; **Region Västra Götaland, Institute of Stress Medicine, Gothenburg,
Sweden; ***Department of Social and Behavioural Studies, Unit of Psychology and Organizational Studies,
University West, Trollhättan, Sweden
ABSTRACT Attention is a basic cognitive function necessary in most daily activities. Beneficial
effects on cognitive abilities after exposure to nature have been reported. To explore if relaxation
indoors and in nature differently affect directed attention and physiological measures, 51
participants (39 women) were measured on directed attention with the Necker Cube Pattern Control
Test before and after a guided progressive relaxation session indoors and outdoors in nature.
Additionally, systolic and diastolic blood pressure and heart rate were measured before and after
the relaxation. Participants’environmental preference was explored. The main result showed an
environmental effect on directed attention in favour of the natural environment. No similar
environmental effect on physiological measures was seen. The results indicate that relaxation in
natural environments had a positive effect on directed attention and hence could be an important
component for preventive and rehabilitative interventions for stress-related symptoms.
KEY WORDS: blood pressure, the Necker Cube Pattern Control Test, nature, cognitive capacity,
stress management
1. Introduction
1.1. Attention and Concentration
Attention and concentration are basic cognitive functions necessary for the individual in
most daily activities. Ability to direct attention, shift attention between different objects
and shield off distracting and irrelevant stimuli is required to initiate, conduct and
complete tasks (Lezak, Howieson, & Loring, 2004). The capacity to direct attention is
easily fatigued when being overused and without recovery breaks directed attention
fatigue (DAF) may occur (Kaplan, 1995). DAF may manifest as concentration
Correspondence Address: Eva Sahlin, Institute of Stress Medicine, Carl Skottbergs gata 22b, 413 19
Göteborg, Sweden. Email: eva.sahlin@slu.se
© 2014 Landscape Research Group Ltd
Landscape Research, 2014
http://dx.doi.org/10.1080/01426397.2014.982079
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problems, deficiencies in the capacity to shut out irrelevant stimuli, increased irritability
and as a greater tendency to make mistakes or misjudgements. Cognitive failure
commonly occurs in connection with stress-related mental disorders (Glise,
Hadzibajramovic, Jonsdottir, & Ahlborg, 2010) and constitutes one of the main reasons
for the reduced work ability and long-term sick leave among patients diagnosed with
stress-related mental disorders. A previous study has shown that patients with stress-
related disorder performed worse than non-patients on domains closely connected to
directed attention and DAF such as speed, attention, working memory and executive
functions (Jonsdottir et al., 2013). Studies on relaxation, mindfulness and progressive
muscle relaxation, have shown to improve cognitive functions such as attention,
working memory and executive functioning for elderly as well as for a younger
population (Galvin, Benson, Deckro, Fricchione, & Dusek, 2006; Sun, Kang, Wang, &
Zeng, 2013; Zeidan, Johnson, Diamond, David, & Goolkasian, 2010).
1.2. Nature and Attention
There are a considerable number of studies exploring different effects on people’s
health being exposed to different types of nature. It has been shown in earlier studies
that these effects relate to a reduction of stress and an increased cognitive capacity
(Adevi & Grahn, 2011; Grahn & Stigsdotter, 2003; Grahn & Stigsdotter, 2010; Hartig
& Staats, 2006; Kaplan & Kaplan, 1989; Korpela & Ylén, 2005; Kuo & Sullivan,
2001; Lottrup, Grahn, & Stigsdotter, 2013; Ottosson & Grahn, 2008; Tennessen &
Cimprich, 1995; Ulrich, 1984; Ulrich et al., 1991).
In concordance, a large number of studies have shown that exhausted attention may be
recovered in nature environments (Berto, 2005; Hartig & Staats, 2006; Herzog, Black,
Fountaine, & Knotts, 1997; Kaplan, 1995,2001; Kaplan & Berman, 2010; Kaplan &
Kaplan, 1989; Staats, Kieviet, & Hartig, 2003). The underlying theory referred to for
explaining these effects is the attention restoration theory—ART (Kaplan, 1995). ART
focuses on two different types of attention systems: (i) directed attention which is a
voluntary controlled system with limited capacity that is easily fatigued and (ii)
spontaneous attention later changed to fascination which is a non-voluntarily controlled
attention system with more or less unlimited capacity. The directed attention may
according to ART restore its depleted capacity in nature by triggering fascination which
in turn allows the directed attention to rest. This theory has been tested and supported in
a number of studies (Berto, Baroni, Zainaghi, & Betella, 2010; Cimprich, 1993; Herzog
et al., 1997; Ottosson & Grahn, 2005; Staats et al., 2003; Tennessen & Cimprich, 1995).
In a recently developed version of the original ART, cognitive effects on interacting with
nature have been demonstrated by Berman, Jonides, and Kaplan (2008) specifically
showing that interacting with nature most prominently affected the directed attention
opposed to orienting and alerting attention for a healthy population. Furthermore
improvements in the short-term memory after a walk in nature was shown by Berman
et al. (2012) for individuals with major depression.
1.3. Nature and Stress
A second theory based on the biophilia hypothesis (Wilson, 1984), the psycho
evolutionary theory, claims that an individual in contact with nature is affected both
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physiologically and psychologically (Ulrich et al., 1991). If the environment is
experienced as non-threatening, there is a wide range of positive effects on
physiological responses, including decreased blood pressure and heart rate (HR) after
stress arousal. These effects have been explored in earlier studies (Kjellgren &
Buhrkall, 2010; Ottosson & Grahn, 2006; Ulrich, 1984; Ulrich et al., 1991).
1.4. Restorative Characteristics in Natural Environments
Different types of natural environments have been shown to differently affect mood,
well-being and stress. For instance, Martens, Gutscher, and Bauer (2011) explored
whether two different nature conditions (tended forest and wild forest) affected well-
being differently in healthy individuals. They found stronger increased self-reported
good mood and calmness during a 30 min walk in a tended forest (maintained and with
low amount of dead trees) compared to a walk in a wild forest (high amount of dead
trees). In our study, the “park-site”can be compared to the tended forest and “wood-
edge”shows some resemblance to the wild, less maintained forest.
Grahn et al. (2010) have identified eight main characteristics in nature: serene
(defined as peace, silence, safe and secure), nature (wild nature not created by humans),
rich in species (a room offering variety of animals and plants), space (a nature room
offering a feeling of entering another world), prospect (a view, that invites you to stay),
refuge (safe and secluded place where you can relax), social (a social arena or meeting
place) and culture (with evidence of people′s values, beliefs efforts and toils). They
maintain that these eight characteristics in the physical environment in different ways
afford people support in their everyday life, mentally and physically. Grahn and
Stigsdotter (2010) found that the more stressed a person is, the more he/she searches
for a safe retreat in green open spaces (refuge); the second most important characteristic
in the study was nature, which in their interpretation can provide the visitor with a
sense of context, perhaps connectedness with nature—with no demands: one can let go
of control; it is about the experience of “being away”(from the everyday situation),
“compatibility”(with the visitors` needs) and “extent”(a sense of cohesive whole at the
same time being spacious) according to Kaplan and Kaplan (1989). A further
characteristic of relevance that directly seems to affect the sense of security is found if
there are possibilities to hear soothing sounds: the characteristic serene (Grahn et al.,
2010). Thus, the relation between individuals′needs and the characteristics in the
natural environment appears to be important.
1.5. Relaxation Therapy
Different kinds of relaxation therapies have been frequently used in clinical practice in
order to improve cognitive functions and reduce the effects of stress on physiological
markers such as blood pressure, HR and muscle tension. Although the scientific
evidence regarding the effectiveness of these therapies on cognitive deficits and
physiological arousal has been fairly weak, a review has concluded that relaxation
meditation programmes were associated with a significant reduction in blood pressure
in individuals with elevated blood pressure, while other forms of relaxation methods
like biofeedback, progressive muscle relaxation or stress management training did not
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show a similar effect (Rainforth et al., 2007). However, regarding effects of relaxation
on blood pressure and cognition in individuals with “normal”blood pressure one earlier
study has reported improvements in tasks requiring attention after a progressive
relaxation session (Scheufele, 2000). Furthermore, and in concordance with the above
mentioned results, a study conducted in an occupational setting indicated that a 15 min
chair-based session of guided meditation had acute positive effects on both
physiological (including blood pressure) and psychological markers of stress (Melville,
Chang, Colaguiri, Marshall, & Cheeman, 2012).
1.5.1. Relaxation and Nature. The attention restoration theory (Kaplan, 1995) focuses
on the improved cognitive ability especially in terms of directed attention capacity. In an
immersed version of the original theory, the same author suggests that meditation
(relaxation) in nature enhances the restorative effects on decreased cognitive capacity
(Kaplan, 2001). During interviews with participants in a nature-based therapy
programme conducted among patients with stress related disorders a majority perceived
the outdoor guided relaxation session as more effective and more pleasant than the same
relaxation performed indoors (Sahlin, Vega Matuszczyk, Ahlborg, & Grahn, 2012). As
mentioned before, cognitive impairment including decreased directed attention in
individuals with stress-related symptoms have previously been recognised as an early
sign preceding more manifest stress-related disorders (Glise et al., 2010; Jonsdottir et al.,
2013). Thus, exploring the effects of methods aiming to enhance directed attention are
crucial for the prevention of these disorders. Hence, the aim of this study was:
(1) to explore if directed attention, blood-pressure and heart-rate are affected
differently by a guided progressive relaxation session (henceforth referred to as
relaxation), depending on the environmental condition i.e. indoor or outdoor in
nature.
(2) to explore if different types of nature could be of importance for the
intervention.
2. Method
2.1. Recruitment and Subjects
Participants were recruited through information sheets on message boards and in
canteens in a variety of workplaces such as community services, industries, schools,
fitness centres and at different institutions at a university. A compensation of 500 SEK
(58 EUR, 75 USD) was offered after full participation.
Seventy-one individuals were contacted by phone for further information and
detailed written information about the study was emailed. Twenty individuals were
unable to participate for various reasons (e.g. child birth, moving house to another
town, illness, lack of time due to heavy work load, vacation). Finally, the study
population consisted of 51 persons (39 women and 12 men), mean age 45 years
(women 46, range 24–66 and men 41, range 21–72), and 82% had university
education. All participants signed informed consent, and the study was approved by
the regional ethical board.
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2.2. Study Design and Procedure
The study was conducted according to case-cross-over design, factor 1 before and after
the relaxation and factor 2 relaxation indoors and outdoors in nature. Directed attention
and physiological factors were measured before and after the relaxation session in both
environments. Subjects were randomly assigned to have their first intervention occasion
either indoors or outdoors.
2.3. The Indoor and Outdoor Environments
Two different outdoor sites were chosen for this study, one in woodland in a large city
park (Figure 1a and 1b) and the other in the wood edge at the border of a nature
Figure 1a. The park site.
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reserve with uncultivated wild nature (Figure 2a and 2b). The indoor test sites
(Figure 3) were small white painted rooms without any decorations on the walls or
potted plants. The windows were covered with blinds or curtains to exclude any nature
view. During the test, the participant and leader sat opposite each other with a table
between them. During the indoor relaxation, the participants sat in front of a white wall
in the same chair as during outdoor relaxation (Figure 3).
2.3.1. The Park Site. The participants’view during the relaxation in the park was
towards a grassy slope sparsely vegetated with deciduous and coniferous trees
(Figure 1b). The prominent dimensions according to Grahn et al. (2010) would be
prospect, and culture. One gravel path was directly in front of the place for the
relaxation. At 15 m distance from the participant placards at both ends of the path
requested “Please do not disturb. Research in progress”. Park visitors respected the call,
chose other paths and no one passed in front of the participants.
Sounds from the heavy traffic on the multilane road nearby could constantly be
heard, and during several relaxation sessions motorised tools for the park management
were heard. The room for the indoor relaxation as well as pre- and post-tests was in a
nearby building 120 m (131 yards) away from the relaxation site.
2.3.2. The Wood Edge Site. Participants’view during the relaxation in the wood edge
was into wild nature; a path leading further along the wood edge, a rocky slope, ferns,
plants and mixed deciduous trees (Figure 2b). The primary dimensions in this site
would be serene, nature, space and refuge (Grahn et al., 2010). The area was sheltered
Figure 1b. Participants view at the park site.
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by a curtain of trees towards an adjacent open grassy common and the participant sat
without being seen. Sounds that could be heard were mostly from birds and the wind.
At a distance sounds from traffic and a remote shooting range were very slightly
noticeable. The room for the indoor relaxation (Figure 3) was similarly arranged to the
indoor relaxation (connected to the park site) and at a distance of 120 m (131 yards)
from the outdoor relaxation site.
2.4. Intervention
The relaxation session consisted of a 30 min programme based on the theory
concerning residual tension by Edmund Jacobson (1938). According to this theory, a
Figure 2a. The wood edge.
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gradual relaxation in a group of muscles can be obtained by a guided general muscle
relaxation focusing on contractions followed by a relaxation of the same muscle group.
This method has through the years been modified and the version used in this study
was based on a well-known relaxation programme elaborated by Uneståhl (Johansson
Figure 2b. Participants view at the wood edge.
Figure 3. Indoor relaxation.
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& Uneståhl, 2006). According to Uneståhl gradual relaxation of a muscle group can be
obtained by using thoughts involving feelings of warmth and heaviness without using
muscle contractions. This method has been frequently used in general practice among
physiotherapists in order to optimise muscle relaxation, enhance stress reduction and
improve well-being. In our intervention, a recorded version (CD) of Uneståhl′s original
programme was used which also was read by Dr Uneståhl himself.
2.4. The Test Situation
Data collection was undertaken between July and early October during two consecutive
years which can be described as “typical Swedish summers”. The temperature during
the tests was registered. Each participant performed the test twice, individually, 49
participants with an interval of 7–14 days; two participants had intervals of 18 and
31 days, respectively. Tests were carried out on weekdays between 9 am and 8 pm.
During the summer months, there is daylight until late evening in Sweden. Each
session lasted approximately 90 min.
We assumed that a vacation might positively influence cognitive functioning such as
directed attention. Hence, it was decided that all study participants should be engaged
in their everyday activities such as work and study to minimise the risk of such
recreational influences on the test results.
A protocol with the test procedures chronologically listed was used by the test leader
to register systolic blood pressure, diastolic blood pressure, and HR and also to ensure
the order in which the different parts of the test should be carried out.
On arrival, on the first occasion, participants signed a consent form agreeing to
participate in the study. They were connected to blood-pressure and heart-rate
measuring equipment and they answered a validated questionnaire (Shirom-Melamed
Burnout Questionnaire, SMBQ, Melamed, Kushnir, & Shirom, 1992) regarding
potential symptoms of burnout. SMBQ was answered only at the first test occasion in
order to categorise the variability in self-reported stress related symptoms in our study
population. Directly, thereafter, they completed a directed attention test followed by
registration of the physiological measures described above three times and subsequent
calculation of the means by the apparatus. For the indoor session, the relaxation session
followed directly and for the outdoor session the participant made a 120 m (131 yards)
walk to the relaxation site. The participants sat down in the comfortable lounge chair
with adjustable tilt and after a short rest (approximately five minutes) to normalise
blood pressure and HR after the physical activity of walking, the relaxation followed. A
fleece blanket was offered for cover and was used by all participants in the outdoor
relaxation and by some during the indoor relaxation. The chair was placed in the shade
under a large tree.
The physiological measures were registered again directly after the relaxation in both
environments. During the walk to the relaxation site, the participants were informed
that the walk back to the test room would be in silence in order to avoid interference of
the mood/state from the relaxation. To compensate for the physical activity of the short
walk at the outdoor relaxation an equal physical demanding walk indoors was made
after the indoor relaxation.
The tests were conducted during summer for the wood edge relaxation and summer
and early autumn for the park relaxation. On two test occasions, there was some very
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short light rain during the relaxation but it was not noticeable under the dense canopy
of the tree. Participants were instructed to be appropriately dressed for the weather that
prevailed on the test day.
2.5. Measurements
2.5.1. Directed Attention. The directed attention capacity was measured by the
Necker Cube Pattern Control Test (NCPCT) (henceforth referred to as the Necker cube
test; Cimprich, 1990). The Necker cube (Figure 4) is a wire frame drawing of a cube
with no depth cues. It can be interpreted in two ways; with the front or the back of the
cube in focus. Its specific feature is that it spontaneously changes from which
perspective (front or back) it appears for the viewer. To hold one perspective and to
avoid reversals is a demanding task and to hinder the shifts in perspective by an effort
of will is considered to be a measure of an individual’s directed attention capacity. The
test has been used in a variety of studies in order to capture the capacity for directing
attention (Cimprich, 1993; Hartig et al., 2003; Ottosson & Grahn, 2005; Tennessen &
Cimprich, 1995).
The Necker cube test procedure was as follows:
After being familiarised with the feature of the Necker cube the participant was
instructed to look at the picture of the cube and mark with the tap of a pen each time the
perspective shifted during the 30-second duration of the test. This was the baseline score.
Instruction:
I want you to look at the figure and tap with the pen on the table every time you
think that the figure changes from being inward to outward, or vice versa. I will
tell you when to start and stop. Any questions? Begin
Next, the participant was instructed to hold one perspective as long as possible during
another 30 seconds but to tap when there nevertheless was a shift of perspective. This
was the controlled score (the holding condition). Instruction:
Figure 4. Necker cube.
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Now this time, I want you to try to hold each pattern for as long as you can, but
tap each time the pattern reverses. I’ll tell you when to start and stop. Remember:
try to hold each pattern for as long as you can, but tap for each change. Any
questions? Begin. (Cimprich, 1990)
The time between the two sessions of the Necker cube test (performed before and after
the relaxation) could range from 45 to 55 min.
A digital timer was used and the test leader told the participants when to start and to stop.
The taps were registered in a protocol by the test leader.
The number of reversals at the holding condition was used to produce the primary
outcome measure of the Necker cube test. The lower the score is, the better the directed
attention.
2.5.2. Physiological Measures. In order to measure systolic and diastolic blood
pressure and HR, we used the OMRON M7 Digital Automatic Blood Pressure Monitor.
Both blood pressure and HR were measured before and after the relaxation in each
condition (outdoors and indoors). On each occasion, a mean value for each subject was
calculated on the basis of three successive measurements for all three outcome variables.
2.5.3. Cognitive Weariness. Since we assumed that the participants’cognitive status
may be of significance for the outcome of the Necker cube test as well as for the
environmental impact we used the subscale “cognitive weariness”from the Shirom-
Melamed Burnout Questionnaire (SMBQ; Melamed et al., 1992) to measure self-rated
cognitive capacity. The questionnaire was administered only at the first test occasion
due to the fact that this scale is not considered to measure acute cognitive weariness
but rather the level of cognitive weariness over a longer period of time. The scale
contains six questions: “I am too tired to think clearly”;“I have difficulty
concentrating”;“My thinking process is slow”;“My mind is cloudy”“I have difficulty
thinking about complex things”,“I feel I am disorganised lately”. A seven-point scale
ranging from 1 (almost never) to 7 (almost always) was used for all items. A mean
value for the six questions was calculated and the participants were categorised into
three groups based on a tertile split. The group with the lowest mean values was
assumed to have better cognitive capacity (= less weary ) than the one with the highest
mean values (= more weary).
2.5.4. A Question of Preference. After the second test occasion a question regarding the
environmental preference was orally asked: Which of the relaxation sessions, the outdoor
or the indoor, did you like the best? The answers and comments were registered in the test
protocol by the test leader and were read aloud to be confirmed by the participant.
2.6. Statistical analysis
Descriptive statistics are given in terms of means and standard deviations (SDs)
(continuous variables). Using Statistical Package for the Social Sciences version 20.0
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the General linear model (GLM) for repeated measures design with two crossover
factors was conducted separately for each outcome (Necker cube test, systolic and
diastolic blood pressure and HR).
The first factor (before and after relaxation session) evaluated possible
relaxation effect on the outcome regardless of the environment.
The second factor (outdoor and indoor) evaluated possible differences between
the two environments (pooled before and after values outdoor compared to
pooled values indoors), the environment effect.
The interaction between relaxation effect and environmental effect evaluated
whether the possible change in outcomes (before—after) differed between the
two environments.
The mean difference and the 95% confidence interval (CI), the Wilks’Lambda, F and
p-values for each factor and outcome are presented. The level of significance was set at
p< 0.05.
It was assumed that cognitive weariness and the different outdoor environments
(park-site, wood edge site) might influence the directed attention and analyses were
performed to explore such relations.
3. Results
3.1. Descriptive Measures
Both the directed attention and the physiological measures showed lower mean values
after compared to before the relaxation (Table 1). Necker cube test scores (mean
values) were lower in the outdoor than the indoor condition both before and after
relaxation; however, the differences in reversals were larger in the outdoor condition
indicating improved attention outdoors. The physiological measures were similar in the
two environmental conditions (outdoors versus indoors). Mean temperature outdoors for
tests conducted in the park site was 15, 1 °C (range 10.1–27. 3) °C and for the wood
edge 18, 3 °C (range 13. 2–23. 8).
3.2. Effects of Relaxation and Environment
There was a statistically significant relaxation effect, regardless of the environment, on
all physiological measures (Table 2). A significant environmental effect on the directed
attention capacity (Necker Cube) in favour of the outdoor condition was obtained
(p= 0.012). No interaction between relaxation and environment was observed.
3.3. Effects of Different Natural Environments
There was a statistically significant relaxation effect (p= 0.044) for the park site but
not for the wood edge (p= 0.838) (Table 3). No environmental effects and no
interaction between relaxation and environment was observed (Table 3).
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Participants tested in the park site (n= 29) showed lower scores in general compared
to the wood edge group (n= 22). The reduction in the number of reversals after
relaxation was somewhat greater in the park site group but the wood edge group
showed the largest difference between indoor and outdoor tests (Table 4). However, no
significant differences were found between “before and after relaxation”in either of the
groups (p-value not shown).
Table 2. Mean differences (diff) and 95% CIs for the effect of relaxation (RE), environment
(indoor/outdoor, EE) and interaction of RE and EE on directed attention capacity measured with
the NCPCT, and effects on systolic (SBP) and diastolic (DBP) blood pressure, and HR. Analysed
by GLMs for repeated measures
Relaxation effect Environmental effect
Interaction effect
(relaxation × environment)
Diff (95% CI)
Wilks’Lambda (F); p
Diff (95% CI)
Wilks’Lambda (F); p
Diff (95% CI)
Wilks’Lambda (F); p
NCPCT 0.30 (−0.13, 0.74) −0.64 (−1.13, −0.14) 0.37 (−0.33, 1.07)
0.96 (2.00); 0.164 0.88 (6.72); 0.012 0.98 (1.15); 0.289
SBP 6.27 (4.61, 7.94) −0.47 (−2.37, 1.43) −2.0 (−4.36, 0.36)
0.47 (57.49); 0.000 1.00 (0.25); 0.621 0.95 (2.89); 0.095
DBP 4.47 (3.41, 5.53) −0.86 (−2.11, 0.38) −0.86 (−2.59, 0.87)
0.41 (71,70); 0.000 0.96 (1.94); 0.170 0.98 (1.00); 0.321
HR 6.65 (5.60, 7.70) −1.04 (−2.92, 0.84) −0.98 (−2.64, 0.68)
0.24 (161.50); 0.000 0.98 (1.23); 0.273 0.97 (1.40); 0.242
Table 1. Mean and SD for directed attention capacity measured with the NCPCT, and also for
systolic (SBP) and diastolic (DBP) blood pressure, and HR before and after the indoor and
outdoor guided progressive relaxation session
Measure Outdoors before Outdoors after Indoors before Indoors after
Mean (SD) Mean (SD) Mean (SD) Mean (SD)
NCPCT 5.27 (2.25) 4.78 (2.74) 5.73 (2.82) 5.61 (3.63)
SBP 114 (15.62) 108 (14.61) 115 (16.34) 108 (14.84)
DBP 76 (9.23) 72 (8.05) 77 (9.38) 72 (9.41)
HR 69 (9.02) 63 (8.01) 70 (9.44) 63 (7.58)
Table 3. Mean differences (diff) and 95% CIs for the effect of relaxation (RE), environment
(indoor/outdoor, EE) and interaction of RE and EE on directed attention capacity measured with
the NCPCT Analysed by GLMs for repeated measures
Relaxation effect Environmental effect
Interaction effect
(relaxation × environment)
Diff (95% CI)
Wilks’Lambda (F); p
Diff (95% CI)
Wilks’Lambda (F); p
Diff (95% CI)
Wilks’Lambda (F); p
NCPCT
Park site 0.59 (0.02, 1.15) −0.41 (−0.88, 0.05) 0.30 (−0.78,1.33)
0.86 (4.46) 0.044 0.89 (3.35) 0.078 0.99 (0.29) 0.597
Wood
edge
−0.07 (−0.75, 0.62) −0.93 (−1.95, 0.08) 0.50 (−0.43,1.43)
1.00 (0.04) 0.838 0.85 (3.68) 0.069 0.94 (1.26) 0.274
An Experimental Study Using a Relaxation Intervention 13
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3.4. Influence of Cognitive Weariness
Possible influences of cognitive weariness on the first test occasion and type of outdoor
environment on directed attention were explored using Necker cube scores (Table 5).
There were no significant differences for relaxation effect or environmental effect and
no interaction between relaxation and environment was observed (result not shown).
However, in the group with low cognitive weariness (= less weary; n= 18), a
reduction in the number of reversals after relaxation was seen for both indoor as well
as outdoor sessions. For the group with high cognitive weariness (= more weary;
n= 16), there was a reduction in reversals in the outdoor condition but a small increase
in reversals in the indoor condition.
3.5. Environment Preference
The question: Which of the relaxation sessions, the outdoor or the indoor, did you like
the best? was answered by 50 of the 51 participants. A substantial majority of the
participants (71%) preferred the outdoor relaxation and when separately analysed, the
preference for the outdoor relaxation was 73% for the wood edge group and 69% for
the park group.
4. Discussion
4.1. Restoration of Directed Attention Capacity, Blood Pressure and Heart Rate
The main result from this study is that there was an environmental effect on directed
attention in favour of the outdoor nature environment. Interestingly, there was no
Table 4. Mean and SD for directed attention capacity measured with the NCPCT before and after
the indoor and outdoor guided progressive relaxation session in the park site and by the wood
edge
Condition Outdoors before Outdoors after Indoors before Indoors after
Mean (SD) Mean (SD) Mean (SD) Mean (SD)
Environmental conditions
Park site 5.14 (2.05) 4.41 (2.47) 5.41 (2.67) 4.97 (3.08)
Wood edge 5.45 (2.52) 5.27 (3.04) 6.14 (3.03) 6.45 (4.18)
Table 5. Mean and SD for directed attention capacity measured with the NCPCT before and after
the indoor and outdoor guided progressive relaxation session among participants with low and
high cognitive weariness
1
Condition Outdoors before Outdoors after Indoors before Indoors after
Mean (SD) Mean (SD) Mean (SD) Mean (SD)
Cognitive weariness
Less weary 5.67 (2.28) 4.72 (2.82) 5.33 (2.22) 4.83 (2.53)
More weary 5.31 (2.33) 4.75 (2.32) 6.13 (3.32) 6.19 (4.55)
1
Lowest and highest tertile of the mean score on the subscale cognitive weariness from the
Shirom-Melamed Burnout Questionnaire (Melamed et al., 1992).
14 E. Sahlin et al.
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similar effect on blood pressure or heart rate. The expected physiological effect of the
relaxation was however clear, thus confirming that the relaxation method worked in
both conditions. In the analyses of the physiological measures no environmental effect
could be seen, although a large majority of the participants preferred to perform the
relaxation in the outdoor condition.
We had assumed that an interaction between environment and relaxation should
appear, but found no support for the interaction hypothesis.
According to the ART concept, previously described in section 1.2 of this paper, a
depleted directed attention can recover and regain vitality in nature and our results
partly support this. However, the time frame seems to be of vital importance for
regaining full directed attention capacity. Although our study points to a positive impact
from nature on directed attention, it maybe that a more regularly repeated intervention
for a longer period is necessary to provide clearer changes to the directed attention than
the 30 min intervention in our study (Berto, 2005; Cimprich, 1993).
4.2. Outdoor Environmental Conditions
Regarding the two different outdoor environments, the reduction in the number of
reversals after the relaxation was somewhat greater in the park site group, but the wood
edge group showed the largest difference between the indoor and outdoor tests. We
assumed this latter site would contain more characteristic features, necessary for mental
restoration according to Kaplan and Kaplan (1989). The more wild and serene nature
type may contribute to the explanation of why the directed attention showed better
capacity in the wood edge compared to the park site. This could partly be explained by
Grahn et al’s. (2010) suggestion, as described in section 1.4 above, that specific
characteristics in nature or in a garden may affect individuals in various ways or may
be preferred differently depending on factors such as the individual’s level of stress or
mood at the moment. Earlier studies have found that individuals highly affected by
stress preferred the characteristics nature, refuge, and rich in species especially when
rest activities were needed (Grahn & Stigsdotter, 2010; Stigsdotter & Grahn, 2011). A
more serene environment or an environment rich in species, and characterised as
nature, space and refuge like the wood edge, may be experienced as more compatible
when relaxation and recovery are needed. The wild nature with birdsong and fewer
artificial sounds like those from traffic could be interpreted as less demanding and
therefore producing better recovery than a parkland setting with obvious signs of
human interference. In our study, there were noises from traffic and from machines
used for the park maintenance during the relaxation in the park, while in the wood
edge there were more natural sounds from the wind rustling in the foliage and
birdsong. Some recent studies have indicated that nature’s sound may have a positive
impact on stress recovery (Annerstedt et al., 2013; Alvarsson, Wiens, & Nilsson, 2010;
Jahncke, Hygge, Halin, Green, & Dimberg, 2011).
Kaplan (2001) suggested that relaxation through meditation may enhance the
restorative effect of a restorative environment, but the results from this study did not
clearly reveal if a progressive relaxation session in nature may give the same effect.
The preference for nature relaxation as expressed by the majority of participants may
indicate such an effect, although this is not clearly shown in this study.
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4.3. Cognitive Weariness
Participants scoring high on cognitive weariness (more weary) differed most from the
group with low score (less weary) in having a higher mean number of reversals both
before and after the relaxation when performing the relaxation indoors. Looking at the
difference in Necker cube score, the relaxation indoors and outdoors elucidated that in
the “more weary group”the outdoor relaxation resulted in a better performance than the
indoor relaxation with respect to directed attention. This indicates (although not
statistically significant) that performing the relaxation outdoors was more effective than
performing the same relaxation indoors for the “more weary group”. This is in line
with findings from an earlier study showing that individuals experiencing stress
preferred the environmental characteristics described as serene, nature and refuge by
Grahn and Stigsdotter (2010). Since the environments present in our study were similar
in characteristics to the above mentioned, our study indicates that relaxation in such an
environment could have a beneficial impact on directed attention in this type of
population.
4.4. Physiological Measures
The study gives no support for the psychological evolutionary theory (Ulrich, 1984;
Ulrich et al., 1991) as no significant changes due to environmental conditions for the
physiological measures were seen. The significantly lower values on systolic and
diastolic blood pressure and heart rate seen after the relaxation are interpreted as a
consequence of the relaxation (irrespective of type of environment). Several other
studies have reported lowered physiological values after relaxation (Benson, 2000;
Kjellgren & Burkhall, 2010). However, effects from nature on the physiological
measures cannot be completely dismissed; they may have occurred early in the
relaxation in nature but subsided and therefore did not become visible in the
measurements after the 30 min relaxation. Ulrich et al. (1991) found a very rapid onset
of physiological effects, within a few minutes.
4.5. Strength and Limitations
Both the cognitive measures, physiological measures and preferences expressed by the
participants were used in order to look at the phenomenon from several perspectives.
The participants were recruited from the general population including a wide span of
stress levels, state of health and participants from different age groups participated
whereas other studies referred to in this study mostly used elderly persons or a much
younger study population often consisting of students. There may be a risk for selection
bias concerning the underlying reasons for participating with a possible predominance
of participants who are particularly interested in the study topic. The time between
relaxation and the Necker Cube Test may have influenced the results. Another
consecutive study should leave some time after the relaxation for the participants to
normalise before performing the attention test. Some participants followed the
instructions on the CD to close their eyes and thereby shutting out the visual impact
from nature (as well as the indoor environment) during some part of the test.
16 E. Sahlin et al.
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Nevertheless, we do not believe that opened eyes throughout the whole relaxation
session would have altered the impact from nature since experiencing nature is a multi-
sensorial experience and when one sensory dimension is shut out others become more
alert (for instance hearing and touch). In a previous article (Sahlin et al., 2012), as well
as in an ongoing study, it is obvious that the experience of relaxation outdoors in
nature is described precisely in this way, i.e. as a multi-sensory experience where not
only visual impressions are of importance. However, we cannot exclude that there
might have been another effect on directed attention if the participants had been
encouraged to have their eyes open. The weather conditions during the tests, showing a
range from 10 to 27 °C, may be regarded as a big difference and thus disrupting the
results by impeding the ability to relax in the lower temperatures. However, Martens
et al. (2011) have concluded that a similar temperature difference (12–28 °C) during
walks in tended and wild forests did not influence well-being in a comparable study
population.
4.6. Clinical Implication
Our results indicate that relaxation in a park environment or a wood edge can have a
positive effect on directed attention and hence could be considered as an important
component for preventive as well as rehabilitative interventions for stress-related
symptoms.
Acknowledgements
This study was supported by funding from Skaraborgsinstitutet, Skövde and Region
Västra Götaland. We also wish to express our thanks to the Göteborg Botanical Garden
for kindly allowing us to use one part of the park for study purpose. Finally, we would
like to acknowledge all the participants in the study for letting us use their valuable
time, thus making the study possible.
References
Adevi, A. A., & Grahn, P. (2011). Attachment to certain natural environments: A basis for choice of
recreational settings, activities and restoration from stress? Environment and Natural Resources, 1,36–52.
Alvarsson, J. J., Wiens, S., & Nilsson, M. E. (2010). Stress recovery during exposure to nature sound and
environmental noise. International Journal of Environmental Research and Public Health, 7, 1036–1046.
Annerstedt, M., Jönsson, P., Wallergård, M., Johansson, G., Karlson, B., Grahn, P., …Währborg, P. (2013).
Inducing physiological stress recovery with sounds of nature in a virtual reality forest. Physiology &
Behavior, 118, 240–250.
Benson, H. (2000). The relaxation response. New York, NY: Harper Collins.
Berman, M., Jonides, J., & Kaplan, S. (2008). The cognitive benefits of interacting with nature. Psychological
Science, 19, 1207–1212.
Berman, M., Kross, E., Krpan, K. M., Askren, M. K., Burson, A., Deldin, P. J., …Jonides, J. (2012).
Interacting with nature improves cognition and affect for individuals with depression. Journal of Affective
Disorders, 140, 300–305.
Berto, R. (2005). Exposure to restorative environments helps restore attentional capacity. Journal of
Environmental Psychology, 25, 249–259.
Berto, R., Baroni, R. M., Zainaghi, A., & Betella, S. (2010). An exploratory study of the effect of high and
low fascination environments on attentional fatigue. Journal of Environmental Psychology, 30, 494–500.
An Experimental Study Using a Relaxation Intervention 17
Downloaded by [SLU Library] at 04:13 07 January 2015
Cimprich, B. (1990). Attentional fatigue and restoration in individuals with cancer (Unpublished dissertation).
University of Michigan, Ann Arbor.
Cimprich, B. (1993). Development of an intervention to restore attention in cancer patients. Cancer Nursing,
16,83–92.
Galvin, J. A., Benson, H., Deckro, G. R., Fricchione, G. L., & Dusek, J. A. (2006). The relaxation response:
Reducing stress and improving cognition in healthy aging adults. Complementary Therapies in Clinical
Practice, 12, 186–191.
Glise, K., Hadzibajramovic, E., Jonsdottir, I. H., & Ahlborg, G., Jr. (2010). Self-reported exhaustion: A
possible indicator of reduced work ability and increased risk of sickness absence among human service
workers. International Archives of Occupational and Environmental Health, 83,511–520.
Grahn, P., & Stigsdotter, U. K. (2003). Landscape planning and stress. Urban Forestry & Urban Greening, 2,
001–018.
Grahn, P., & Stigsdotter, U. K. (2010). The relation between perceived sensory dimensions of urban green
space and stress restoration. Landscape and Urban Planning, 94, 264–275.
Grahn P., Tenngart Ivarsson C., Stigsdotter U. K., & Bengtsson I.-L. (2010). Using affordances as a health-
promoting tool in a therapeutic garden. In C. Ward Thompson, S. Bell, & P. Aspinall (Eds.), Innovative
approaches to researching landscape and health (pp. 116–154). London: Taylor & Francis.
Hartig, T., Evans, G. W., Jamner, L. D., Davis, D. S., & Gärling, T. (2003). Tracking restoration in natural
and urban field settings. Journal of Environmental Psychology, 23, 109–123.
Hartig, T., & Staats, H. (2006). The need for psychological restoration as a determinant of environmental
preferences. Journal of Environmental Psychology, 26, 215–226.
Herzog, T., Black, A. M., Fountaine, K. A., & Knotts, D. J. (1997). Reflection and attentional recovery as
distinctive benefits of restorative environments. Journal of Environmental Psychology, 17, 165–170.
Jacobson, E. (1938). Progressive relaxation. Chicago, IL: University of Chicago press.
Jahncke, H., Hygge, S., Halin, N., Green, A. M., & Dimberg, K. (2011). Open-plan office noise: Cognitive
performance and restoration. Journal of Environmental Psychology, 31, 373–382.
Johansson, B., & Uneståhl, L.-E. (2006). Stress reducing regulative effects of integrated mental training with
self-hypnosis on the secretion of dehydroepiandrosterone sulphate (DHE-S) and cortisol in plasma: A pilot
study. Contemporary Hypnosis, 23, 101–110.
Jonsdottir, I., Nordlund, A., Ellbin, S., Ljung, T., Glise, K., Währborg, P., & Wallin, A. (2013). Cognitive
impairment in patients with stress-related exhaustion. Stress, 16, 181–190.
Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal of
Environmental Psychology, 15, 169–182.
Kaplan, S. (2001). Meditation, restoration and the management of mental fatigue. Environment and Behavior,
33,80–506.
Kaplan, S., & Berman, M. (2010). Directed attention as a common resource for executive functioning on self-
regulation. Perspectives on Psychological Science, 5,4–43.
Kaplan, R., & Kaplan, S. (1989). The experience of nature –A psychological perspective. New York, NY:
Cambridge University Press.
Kjellgren, A., & Buhrkall, H. (2010). A comparison of the restorative effect of a natural environment with
that of a simulated natural environment. Journal of Environmental Psychology, 30, 464–472.
Korpela, K. M., & Ylén, M. (2005). Perceived health is associated with visiting natural favourite places in the
vicinity. Health & Place, 13, 138–151.
Kuo, F. E., & Sullivan, W. C. (2001). Aggression and violence in the inner city: Effects of environment via
mental fatigue. Environment and Behaviour, 33, 543–571.
Lezak, M. D., Howieson, D. B., & Loring, D. W. (2004). Neuropsychological assessment (4th ed.). New
York, NY: Oxford University Press.
Lottrup, L., Grahn, P., & Stigsdotter, U. K. (2013). Workplace greenery and perceived level of stress: Benefits
of access to a green outdoor environment at the workplace. Landscape and Urban Planning, 110,5–11.
Martens, D., Gutscher, H., & Bauer, N. (2011). Walking in “wild”and “tended”urban forests: The impact on
psychological well-being. Journal of Environmental Psychology, 31,36–34.
Melamed, S., Kushnir, T., & Shirom, A. (1992). Burnout and risk factors for cardiovascular diseases.
Behavioral Medicine, 18,53–60.
Melville, G. W., Chang, D., Colaguiri, B., Marshall, P. W., & Cheeman, B. S. (2012). Fifteen minutes chair-
based yoga postures or guided meditation performed in the office can elicit a relaxation response. Evidence-
based Complementary and Alternative Medicine, 2012, 1–9. doi:10.1155/2012/501986. Epub 2012 Jan 16.
18 E. Sahlin et al.
Downloaded by [SLU Library] at 04:13 07 January 2015
Ottosson, J., & Grahn, P. (2005). A comparison of leisure time spent in a garden with leisure time spent
indoors: On measures of restoration in residents in geriatric care. Landscape Research, 30,23–55.
Ottosson, J., & Grahn, P. (2006). Measures of restoration in geriatric care residences: The influence of nature
on elderly people’s power of concentration, blood pressure and pulse rate. Journal of Housing for the
Elderly, 19, 227–256.
Ottosson, J., & Grahn, P. (2008). The role of natural settings in crisis rehabilitation: How does the level of
crisis influence the response to experiences of nature with regard to measures of rehabilitation? Landscape
Research, 33,51–70.
Rainforth, M. V., Schneider, R. H., Nidich, S. I., Gaylor-King, C., Salerno, J. W., & Andersson, J. W. (2007).
Stress reduction programs in patients with elevated blood pressure: A systematic review and meta-analysis.
Current Hypertension Reports, 9, 520–528.
Sahlin, E., Vega Matuszczyk, J., Ahlborg, G., Jr., & Grahn, P. (2012). How do participants in nature-based
therapy experience and evaluate their rehabilitation? Journal of Therapeutic Horticulture, 22,8–22.
Scheufele, P. M. (2000). Effects of progressive relaxation and classical music on measurements of attention,
relaxation, and stress responses. Journal of Behavioral Medicine, 23, 207–228.
Staats, H., Kieviet, A., & Hartig, T. (2003). Where to recover from attentional fatigue: An expectancy value
analysis of environmental preference. Journal of Environmental Psychology, 23, 147–157.
Stigsdotter, U. K., & Grahn, P. (2011). Stressed individuals′preference for activities and environmental
characteristics in green space. Urban Forestry & Urban Greening, 10, 295–304.
Sun, J., Kang, J., Wang, P., & Zeng, H. (2013). Self-relaxation training can improve sleep quality and
cognitive functions in the older: A one-year randomised controlled trial. Journal of Clinical Nursing, 22,
1270–1280. doi:10.1111/jocn.12096.
Tennessen, C., & Cimprich, B. (1995). Views to nature: Effects on attention. Journal of Environmental
Psychology, 15,77–85.
Ulrich, R. S. (1984). View through a window may influence recovery from surgery. Science, 224, 420–421.
Ulrich, R. S., Simons, R., Losito, E., Fioriti, E., Miles, M. A., & Zelson, M. (1991). Stress recovery during
exposure to natural and urban environment. Journal of Environmental Psychology, 11, 201–230.
Wilson, E. (1984). Biophilia –The human bond with other species. Cambridge, MA: Harvard University
Press.
Zeidan, F., Johnson, S. K., Diamond, B. J., David, Z., & Goolkasian, P. (2010). Mindfulness meditation
improves cognition: Evidence of brief mental training. Consciousness and Cognition, 19, 597–605.
An Experimental Study Using a Relaxation Intervention 19
Downloaded by [SLU Library] at 04:13 07 January 2015
