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A plasma display window?—The shifting baseline problem in a technologically mediated natural world


Abstract and Figures

Humans will continue to adapt to an increasingly technological world. But are there costs to such adaptations in terms of human well being? Toward broaching this question, we investigated physiological effects of experiencing a HDTV quality real-time view of nature through a plasma display ''window.'' In an office setting, 90 participants (30 per group) were exposed either to (a) a glass window that afforded a view of a nature scene, (b) a plasma window that afforded a real-time HDTV view of essentially the same scene, or (c) a blank wall. Results showed that in terms of heart rate recovery from low-level stress the glass window was more restorative than a blank wall; in turn, a plasma window was no more restorative than a blank wall. Moreover, when participants spent more time looking at the glass window, their heart rate tended to decrease more rapidly; that was not the case with the plasma window. Discussion focuses on how the purported benefits of viewing nature may be attenuated by a digital medium.
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Journal of Environmental Psychology 28 (2008) 192–199
A plasma display window?—The shifting baseline problem
in a technologically mediated natural world
Peter H. Kahn Jr.
, Batya Friedman
, Brian Gill
, Jennifer Hagman
, Rachel L. Severson
Nathan G. Freier
, Erika N. Feldman
, Sybil Carre
, Anna Stolyar
Department of Psychology, University of Washington, Seattle, WA 98195-1525, USA
The Information School, University of Washington, Seattle, WA 98195-2840, USA
Department of Mathematics, Seattle Pacific University, Seattle, WA 98119-1957, USA
Department of Psychology, California State University San Bernardino, San Bernardino, CA 92407-2397, USA
Department of Medical Education and Biomedical Informatics, University of Washington, Seattle, WA 98195-7240, USA
Available online 8 May 2008
Humans will continue to adapt to an increasingly technological world. But are there costs to such adaptations in terms of human well
being? Toward broaching this question, we investigated physiological effects of experiencing a HDTV quality real-time view of nature
through a plasma display ‘‘window.’’ In an office setting, 90 participants (30 per group) were exposed either to (a) a glass window that
afforded a view of a nature scene, (b) a plasma window that afforded a real-time HDTV view of essentially the same scene, or (c) a blank
wall. Results showed that in terms of heart rate recovery from low-level stress the glass window was more restorative than a blank wall; in
turn, a plasma window was no more restorative than a blank wall. Moreover, when participants spent more time looking at the glass
window, their heart rate tended to decrease more rapidly; that was not the case with the plasma window. Discussion focuses on how the
purported benefits of viewing nature may be attenuated by a digital medium.
r2007 Elsevier Ltd. All rights reserved.
Keywords: Nature; Views; Technology; Plasma display; Physiology
1. Introduction
Digital technologies will increasingly mediate the human
experience of the natural world. We know, for example, that
through television, video, and the Web rather than experienced
directly (Kahn & Kellert, 2002). Other technologies may well
take hold. For example, there is some evidence that robotic
pets (e.g., Sony’s AIBO) will offer partially compelling
substitutes to live animals for children (Kahn, Friedman,
Perez-Granados, & Freier, 2006;Melson et al., 2005)andthe
elderly (Beck, Edwards, Kahn, & Friedman, 2004). Or
consider a ‘‘Telegarden’’: a community garden that allows
users to plant and tend seeds in a remote garden by controlling
a robotic arm through a web-based interface (Goldberg, 2000;
Kahn, Friedman, Alexander, Freier, & Collett, 2005). And
there has also been ‘‘Telehunting’’: one goes online and can kill
a real animal remotely by controlling a rifle by means of a web-
based telerobotic installation (Root, 2005). If such technolo-
gical trends continue, which seems likely, then an important
question needs to be answered: What are the physical and
psychological effects of experiencing technologically mediated
nature? This paper reports a study that investigated this
An empirical starting point for this study builds on the
literature that supports the proposition that people benefit
by experiencing many aspects of a diverse natural world
(Beck & Katcher, 1996;Frumkin, 2001;Kahn, 1999;
Wilson, 1984). In one canonical study, for example, Ulrich
(1984) examined the potential differences in the recovery of
patients after gall bladder surgery depending on whether
the patients were assigned to a room with a view of a
natural setting (a small stand of deciduous trees) or a view
0272-4944/$ - see front matter r2007 Elsevier Ltd. All rights reserved.
Corresponding author. Tel.: +1 206 616 9395; fax: +1 206 616 5149.
E-mail address: (P.H. Kahn Jr.).
of a brown brick wall. Patients were paired on relevant
variables that might affect recovery (e.g., age, sex, weight,
tobacco use, and previous hospitalization). Results showed
that ‘‘patients with the natural window view had shorter
postoperative hospital stays, had far fewer negative
comments in nurses’ notes (‘patient is upset,’ ‘needs much
encouragement’) and tended to have lower scores for minor
postsurgical complications such as persistent headache or
nausea requiring medication. Moreover, the wall-view
patients required many more injections of potent painkil-
lers, whereas the tree-view patients more frequently
received weak oral analgesics such as acetaminophen’’
(Ulrich, 1993, p. 107). Other studies have shown that
interactions with animals (such as a dog, cat, bird, dolphin,
or even small turtle) increase the physiological health,
social competence, and learning opportunities of children,
the elderly, and the general population (Beck & Katcher,
1996;Myers, 1998). Contact with nature can also lead to
‘‘enjoyment, relaxation, and yincreased levels of satisfac-
tion with one’s home, one’s job, and with life in general’’
(Kaplan & Kaplan, 1989, p. 173).
If we accept that interacting with many aspects of nature
can benefit people, then a question arises. There are over
six billion of us on this planet, and through human activity
we pollute the air (and most scientists now recognize a
‘‘greenhouse effect’’), pollute the waters, deplete soil,
deforest, create toxic wastes, and extinguish over 27,000
species each year (100–1000 times the background extinc-
tion rate). If contact with the diversity of nature is so
good for us, then why are we destroying it? One possible
answer is that the baseline for comparing what is normal
continues to shift downward as environmental conditions
As a case in point, consider a study of the environmental
views and values of African American children in the inner-
city of Houston, Texas (Kahn & Friedman, 1995). Results
showed that a significant number of the young children
interviewed in that study understood about the idea of air
pollution; but they did not believe that Houston had such a
problem even though Houston was then (and still remains)
one of the most polluted cities in the US. In interpreting
these results, Kahn and Friedman (1995) suggested that
these children may have lacked a comparative experiential
baseline from cities with less pollution by which to
recognize that Houston was itself a polluted city. Building
on these results, Kahn and Friedman also proposed that
people across generations experience psychologically some-
thing quite similar to the children in Houston, that people
construct a conception of what is environmentally normal
based on the natural world encountered in childhood. The
crux is that with each ensuing generation, the amount of
environmental degradation can increase, but each genera-
tion tends to take that degraded condition as the non-
degraded condition, as the normal experience: a condition
that Kahn (1999, 2002) has termed environmental genera-
tional amnesia, and which more broadly we refer to as ‘‘the
shifting baseline problem.’’
This problem has been recognized in other fields, as well.
Pauly (1995), for example, has written of what he calls the
‘‘shifting baseline syndrome’’ of fisheries:
Essentially, this syndrome has arisen because each
generation of fisheries scientists accepts as a baseline
the stock size and species composition that occurred at
the beginning of their careers, and uses this to evaluate
changes. When the next generation starts its career, the
stocks have further declined, but it is the stocks at that
time that serve as a new baseline. The result obviously is
a gradual shift of the baseline, a gradual accommoda-
tion of the creeping disappearance of resource speciesy
(p. 430).
Along similar lines, Evans, Jacobs, and Frager (1982a,
1982b) showed that long-term residents in Los Angeles,
compared to recent arrivals, showed a greater desensitiza-
tion in their judgments of the severity of the smog problem
to their health. Dubos (1980), too, has argued: ‘‘Any
disease, or any kind of deficiency, that is very widespread in
a given social group comes to be considered as the ‘normal’
state and consequently is accepted as a matter of course
within that group’’ (pp. 250–251).
While the research literature has shown physical and
psychological benefits of experiencing many aspects of
nature, there are also indications that some of these
benefits carry over when experiencing visual representa-
tions of nature. For example, static photographs of nature
have been shown to confer health benefits in a hospital
setting (Ulrich, 1993). People also tend to appreciate and
feel psychologically restored by photographs of nature
(Heerwagen & Orians, 1993;Kaplan & Kaplan, 1989;
Orians & Heerwagen, 1992). There is also some evidence
that videotapes of nature-dominated scenes (compared to
artifact-dominated scenes) can confer quicker recovery
from stress and greater immunization to subsequent stress
(Parsons, Tassinary, Ulrich, Hebl, & Grossman-Alexander,
Building on these findings, Friedman, Freier, and Kahn
(2004) created a technological installation—a ‘‘plasma
window’’—where they installed an HDTV camera on top
of an university building on their campus, and displayed, as
the default image, a real-time local nature view on 50-in
plasma screens. The rationale behind this study was that if
static photographs of nature were beneficial in people’s
lives, then why not capitalize on more cutting-edge
technologies that convey more realistic portrayals of nature
and investigate the effects of a real-time ‘‘streaming’’
nature view for people who otherwise lacked access to the
outside environment. The screens were mounted on the
interior walls (as ‘‘windows’’ to the outside) in windowless
offices of seven faculty and staff within the same building.
Results showed that participants reported an increase in
their psychological well being, cognitive functioning,
connection to the wider social community, and connection
to the natural world. Thus there is some initial evidence
that a plasma window with a compelling nature view can
P.H. Kahn Jr. et al. / Journal of Environmental Psychology 28 (2008) 192–199 193
confer benefits to people who would otherwise be working
in a windowless environment.
A critical question, however, is not just whether there are
benefits of the technologically mediated form, but if there
are, then how those benefits compare to the direct natural
form. For if the technologically mediated form comes up
short compared to the direct form but still confers a
benefit, then in the years ahead we may unknowingly allow
the technologically mediated form to substitute for our
direct experience of nature, shifting the baseline lower for
what can be considered optimal human functioning.
Thus, in the current study, we investigated the physio-
logical effects of experiencing (a) an HDTV quality real-
time view of nature (a similar installation as used by
Friedman et al., 2004), (b) essentially the same view
through a glass window, and (c) no window at all.
Participants came into the office setting under the guise
of a task performance study. While they worked on four
tasks and had two specified resting periods, participants’
heart rate was assessed. Prior to the start of each of the six
activities (the four tasks and the two waiting periods), a
researcher gave each participant instructions for the new
activity. This form of social interaction typically elevated
participants’ heart rate, and thus functioned as a low-level
stressor. A camera (time-synchronized with the physiolo-
gical recording equipment) focused on participants’ faces
to allow coding of the frequency and duration of looking
behavior out the glass window and plasma window, and at
the blank wall. We sought this behavior data so as to allow
us to examine whether physiological recovery might
depend not only on participants being in one of the three
office conditions but on their actually looking out the
We had two hypotheses and two open questions. First, we
hypothesized that in terms of the rate of heart rate recovery
from the low-level stressor the glass window would be more
restorative than the blank wall; it was an open question how
the plasma window would compare to the blank wall.
Second, we hypothesized that when participants spent more
time looking at the glass window, their heart rate would
decrease more rapidly; it was an open question in terms of
rate of recovery when participants spent more time looking
at the plasma window.
2. Methods
2.1. Participants
Ninety participants (all undergraduate students; age
18–34; M¼20.8; SD ¼2.53) were recruited through flyers
posted on a university campus. All participants were
recruited during the summer, prior to the return of students
for the fall term, which started at the end of September.
Thirty participants were assigned to each of the three office
conditions, balanced by gender within condition. Each
participant was compensated with $20.00. The experiment
lasted approximately 1 h.
2.2. The three conditions
Each of the three conditions employed the same office on
the university campus. In the glass-window condition, the
south-facing view through a glass window overlooked a
nature scene that included water in the foreground, as part
of a public fountain area, and then extended to include
stands of deciduous trees on one side, and a grassy expanse
that allowed a visual ‘‘exit’’ on the other. This office view
was chosen to include features that people usually find
esthetically pleasing and restorative in nature (Kaplan &
Kaplan, 1989;Orians & Heerwagen, 1992). The office size
was approximately 13 ft by 81
2ft, with off-white colored
walls, matte finished, 101
2foot ceilings with fluorescent
ceiling lights. An office desk, 71
2ft by 2 ft (32 in high), was
placed in front of the window. A swivel chair was locked
into position on the floor so as to keep constant the
distance to the window.
In a second condition, the plasma window condition, a
50-in plasma screen was inserted into the office window,
entirely covering it (Fig. 1). We then mounted an HDTV
camera approximately 15 ft higher on top of the building
and, through hard cabling, displayed on the plasma screen
essentially the same glass-window view one would see from
inside the office itself. The size of the glass window and
plasma window were virtually identical. The desk was
moved approximately 4 ft from the plasma window so as to
mimic as close as possible from a viewer’s perspective the
experience of the same view through the glass window.
In the third condition, the blank wall condition, we first
sealed off the original glass window with light-blocking
material, and then covered the sealed window with drapes,
Fig. 1. Demonstrator in the plasma window condition. The plasma
window covered up the same-sized window used in the glass-window
condition. The camera that recorded looking behavior can be seen poking
out from the drapes to the left of the plasma window. The drapes were
pulled across the entire wall for the blank wall condition.
P.H. Kahn Jr. et al. / Journal of Environmental Psychology 28 (2008) 192–199194
in effect turning the space into a windowless office. The
desk was moved back to the position as established in the
glass-window condition.
Installing the plasma window required many hours, and
uninstalling it even longer, since the surrounding window
area required re-plastering and repainting after removing
the hardware. As a result, it was not feasible to repeatedly
switch data collection efforts back and forth between the
glass window and plasma window conditions, and thus it
was not possible to randomly assign participants to the
three conditions. We collected all of the plasma window
data prior to collecting data for the glass window. That
said, all of the participants came from a summer-school
population. The plasma window condition was run from
early July to early August, and the glass-window condition
was run from mid-August to mid-September. The blank
wall condition was interspersed throughout the other two
conditions from early July to mid-September. Moreover,
participants during the first 5 weeks of data collection were
assigned to either the plasma window condition (30
participants) or the blank wall condition (15 participants),
while participants during the remaining 5 weeks of data
collection were assigned to either the glass-window
condition (30 participants) or the blank wall condition
(15 participants).
The lighting was kept congruent with the anticipated
contexts of use: the glass-window condition had both
natural light and fluorescent light; the plasma window
condition had light from the display and fluorescent light;
and the blank wall condition had fluorescent light. Because
both light intensity and outside weather had the potential
to differ across conditions, data on these variables were
collected, and subsequent analyses were conducted to
examine their potential role in heart rate recovery.
2.3. Procedure
At the start of the experiment, participants had a 5-min
‘‘waiting period’’ during which they could (depending on
their condition) look out the glass window or plasma
window, or at the blank wall, if they so chose. Then
participants completed a series of four tasks: a 10-min
proofreading task, a 3-min ‘‘name-a-Droodle’’ task that
asked for clever labels for ambiguous drawings, a 7-min
‘‘invent-a-Droodle’’ task that asked for the creation of
one’s own Droodle, and a 10-min ‘‘tin can unusual uses’’
task that asked for different uses for a tin can. The tasks
were chosen to allow for different forms of mental
engagement. Following the tasks, participants had another
5-min waiting period.
2.4. Assessments
To assess heart rate, we used a Biopac MP 100
physiological system with a 2-lead configuration to collect
electrocardiogram (ECG) waveform data at a rate of 200
samples per second. Cardiac interbeat interval (IBI) was
determined from the ECG waveform based on the interval
between R-waves, and heart rate was computed as the
reciprocal of IBI.
To assess looking behavior, we recorded the face of
participants during the experiment by means of a camera
(visible in Fig. 1) that was time-synchronized with the
physiological recording equipment. We subsequently coded
on a second-by-second basis the frequency and duration of
looking behavior out the glass window or plasma window,
or at the blank wall.
Outside weather conditions and light intensity inside the
office were recorded for each experimental session. Cloud-
cover conditions for the start and end of each session were
obtained from surface weather observations at the Seattle
NOAA/NWS Lake Washington weather station,
approximately 3 miles from the office where the experiment
was conducted. These weather observations were then
collapsed into one of three categories (sunny/mostly sunny,
cloudy/mostly cloudy, or mixed) as a single evaluation of
the general weather conditions during the session. Also, a
Minolta TL-1 Illuminance meter was used to measure the
light intensity on the work surface of the desk at the start of
each session. When the desk surface was in direct sunlight
in the glass-window condition, light intensity sometimes
exceeded the meter’s light measurement range of .11—
21,517 lx (.01–1999 ft-c) and hence was recorded as over
21,517 lx (2000+ft-c).
Prior to the start of each of the six activities (the two
waiting periods and four tasks), a researcher gave each
participant instructions for the new activity. This form
of interaction typically elevated participants’ heart rate,
and thus functioned as a low-level stressor. To assess
the rate of heart rate recovery from the resulting low-
level stress, the slope of the least-squares regression line
for each participant’s heart rate was computed as a
function of time during the first 60 s of the activity,
beginning from the moment the researcher left the side of
the participant (to sit behind a partition in a different part
of the experimental room). These slopes were computed
separately for each participant and each activity, yielding
six measures of short-term heart rate recovery for each
2.5. Intercoder reliability
Two individuals independently coded the looking
behavior for 10 participants. Intercoder reliability, using
Cohen’s kappa, showed that k¼.79, which is considered
excellent agreement (Fleiss, Levin, & Paik, 2003).
3. Results
Table 1 provides summary statistics for the slopes of the
least-squares regression lines for heart rate as a function of
Archived weather data available at
P.H. Kahn Jr. et al. / Journal of Environmental Psychology 28 (2008) 192–199 195
time during the first 60 s of each activity.
Visually, these
data are summarized in Fig. 2. The mean slope was
negative across all combinations of condition and activity,
indicating that heart rate typically declined during the first
minute of each activity regardless of condition.
To address our first hypothesis about heart rate recovery
by condition, general linear models (GLM) were used,
treating the six linear regression slopes for each participant
as repeated measures of the rate of heart rate recovery. As
hypothesized, there was more rapid heart rate recovery in
the glass-window condition compared to the blank wall
condition (F(1,58) ¼4.204, p¼.045, Cohen’s d¼.538). In
turn, there was no difference in the heart rate recovery
between the plasma window condition and the blank wall
condition: (F(1,58) ¼.003, p¼.955, d¼.015). Thus, in
terms of this measure of heart rate recovery from low-level
stress, the glass window provided a significant physiologi-
cal benefit over a windowless office (the blank wall
condition), while there was no evidence of a similar benefit
from a plasma window when compared to a windowless
Another way of comparing the functionality of a plasma
window compared to a glass window is in terms of what
participants did with their eyes. How often did they look
out each window, and for how long? Our results showed
that participants looked just as often at the plasma window
(median 58 occurrences per participant) as at the glass
window (median 52 looks per participant) (Mann–Whitney
test, U¼370, p¼.324, ^
). However, the total
duration of looking time was significantly greater in the
glass-window condition (median ¼622.0 s) than in the
plasma window condition (median ¼491.5 s) (Mann–Whit-
ney test, U¼299, p¼.039, ^
y¼.656). Participants spent
much less time looking at the blank wall (median ¼55.5 s)
than either the real window (U¼26, po.0005, ^
y¼.029) or
the plasma window (U¼21, po.0005, ^
y¼.024). In other
words, both windows just as frequently garnered partici-
pants’ attention, and on this measure our results showed
equivalent functionality between the two windows. But the
glass-window view held participants’ attention longer than
the plasma window view.
To address our second hypothesis about heart rate
recovery and looking behavior, we conducted the following
analysis. For each participant in the glass window and
plasma window conditions, the Pearson correlation coeffi-
cient was computed within subject between the duration of
looking during the first 60 s of each activity and the heart
rate slope during the same 60 s. Negative correlations
indicate a tendency for more rapid heart rate recovery with
more looking, while positive correlations indicate a
tendency for slower recovery with more looking. Results
showed the mean correlation for participants in the glass-
window condition (M¼.218, SD ¼.445) was signifi-
cantly less than 0 (t(29) ¼2.683, p¼.012, Cohen’s
d¼.498), while the mean correlation in the plasma
window condition (M¼.144, SD ¼.535) was not signifi-
cantly different from 0 (t(29) ¼1.478, p¼.150, d¼.274).
Thus, on tasks where participants spent more time looking
at the glass window, their heart rate tended to decrease
more rapidly than on tasks where they spent less time
looking at the glass window. This was not the case with the
plasma window, where no relationship was found between
duration of looking at the plasma window and rate of heart
rate recovery.
The experimental design did not directly control for light
intensity and outside weather conditions. Thus we con-
ducted additional analyses to explore differences in these
variables across the three experimental conditions, and the
possible impact of these variables on heart rate recovery.
In terms of outside weather conditions across the three
experimental conditions, the weather was sunny or mostly
sunny for 47% of the sessions with the glass window, 47%
Table 1
Summary statistics for linear regression slopes of heart rate recovery by
activity and condition (in beats per minute per minute (bpm/min))
Activity Glass
Waiting period 1
Mslope 5.10 1.44 3.12 3.24
SD 13.32 15.30 9.12 12.78
Mslope 5.16 4.74 3.30 4.38
SD 9.42 6.60 6.60 7.62
Mslope 7.80 4.80 4.98 5.88
SD 8.22 7.62 6.24 7.44
Tin can
Mslope 7.02 6.54 5.52 6.36
SD 15.06 11.28 8.22 11.76
Mslope 8.88 7.38 6.48 7.56
SD 9.66 8.28 8.58 8.82
Waiting period 2
Mslope 15.18 6.30 8.22 9.90
SD 11.76 17.82 11.58 14.40
Average across all activities
Mslope 8.19 5.19 5.26 6.21
SD 6.91 5.30 3.69 5.58
There were no statistically significant differences between the two
groups of 15 participants in the blank wall condition, either on
demographic variables (gender, age) or on our outcome measures (heart
rate slopes and duration and frequency of looking at the wall). As a result,
the two groups were collapsed into a single group of 30 participants for all
yis a probabilistic measure of effect-size obtained from the
Mann–Whitney U-statistic by ^
y¼U=mn, where m,nare the group sizes.
It provides an estimate of the probability that the value of the variable for
an individual in the first condition will exceed the value for a randomly
selected individual from the second condition (Acion, Peterson, Temple, &
Arndt, 2006).
P.H. Kahn Jr. et al. / Journal of Environmental Psychology 28 (2008) 192–199196
plasma window, and 50% blank wall. The weather was
cloudy or mostly cloudy for 20% of the sessions with glass
window, 33% plasma window, and 30% blank wall. For
the remaining sessions, the weather was a mix of sun and
clouds for 33% of the sessions with the glass window, 20%
plasma window, and 30% blank wall. Pearson’s w
¼2.541, 4 d.f., p¼.637, f¼.166) showed no signifi-
cant difference in weather conditions across the three
experimental conditions. Furthermore, there was no
evidence that the average of the heart rate slopes differed
significantly by outside weather condition, either with all
three experimental conditions combined (ANOVA,
F(2,87) ¼1.469, p¼.236, Z
¼.033) or within each con-
dition separately (glass window: F(2,27) ¼1.939, p¼.163,
¼.125; plasma window: F(2,27) ¼.032, p¼.969,
¼.036; blank wall: F(2,27) ¼.469, p¼.631, Z
Next we compared light intensity on the work surface of
the desk across the three experimental conditions. Results
showed that light intensity was quite similar in the blank
wall condition (median ¼456.4 lx, range 418.7–480.1 lx)
and plasma window condition (median ¼462.8 lx, range
338.0–477.9 lx) (Mann–Whitney test, U¼357.5, p¼.240,
y¼.411). This finding was as expected since these two
conditions occurred in the same office with the same
fluorescent lighting as the primary light source. However,
with the addition of natural light in the glass-window
condition, light intensity was much greater and more
variable (median ¼5010.6 lx, range 277.7 to over 21,517 lx)
than with either the plasma window (U¼29, po.0005,
y¼.967) or the blank wall (U¼30, po.0005, ^
Given the large amount of variability in light intensity in
the glass-window condition, we then examined the
association between light intensity and heart rate recovery
within this condition. For each participant in the glass-
window condition, we computed an average rate of
recovery by finding the mean of the six linear regression
slopes for the first 60 s of each activity. Using the non-
parametric Kendall’s tau-b, the correlation between light
intensity and average rate of recovery was .140, which is
not significantly different from zero (p¼.287). (Descrip-
tively, the positive correlation indicates a slight, though not
statistically significant, tendency toward slower heart rate
recovery with higher light intensity.) In the blank wall and
plasma window conditions there was also no significant
correlation between light intensity and average rate of
recovery, but this is not surprising given the very limited
variation in light intensity in these conditions.
4. Discussion
This study established three key findings. First, in terms
of heart rate recovery from low-level stress, working in the
office environment with a glass window that looked out on
a nature scene was more restorative than working in the
same office without the outside view (the blank wall
condition). Second, in terms of this same physiological
measure, the plasma window was no different from the
blank wall. Third, when participants looked longer out the
glass window, they had greater physiological recovery; but
that was not the case with the plasma window, where
increased looking time yielded no greater physiological
recovery. Thus the results from this study provide a check
on what might otherwise be an unbridled positive judgment
about plasma windows (cf. Friedman et al., 2004),
particularly if one has the option of building or inhabiting
spaces with glass windows offering natural views.
Fig. 2. Heart rate recovery from low-level stress. Values are the mean slope of heart rate (in beats per minute per minute (bpm/min)) during the first 60 s of
each activity. Negative values indicate decreasing heart rate, and points lower on the graph represent more rapid decreases in heart rate. (The activities are
ordered by the overall average slope across all six activities.)
P.H. Kahn Jr. et al. / Journal of Environmental Psychology 28 (2008) 192–199 197
Other research has suggested that people may accrue
physiological and psychological benefits simply by experi-
encing daylight in otherwise inside spaces (Ku
¨ller &
Lindsten, 1992;Leather, Pyrgas, Beale, & Lawrence,
1998; cf. Ku
¨ller & Wetterberg, 1993). Thus it could be
argued that the effects of our current study could be
completely explained on the basis of daylight: that the
glass-window condition was the only condition of the three
that had actual daylight (as opposed to digitally repre-
sented daylight through the plasma window). To partly
address this potential confound, we examined the associa-
tion between light intensity and heart rate recovery within
the glass-window condition. We did not find a significant
correlation. In other words, our data indicate that in the
glass-window condition there was no tendency for heart
rate recovery to be more rapid when the light intensity was
greater. In contrast, when we examined the relationship
between time spent looking at the window and heart rate
recovery in the glass-window condition, we did find a
significant association. While this result does not rule out
the possibility that part of the observed difference in heart
rate recovery between the blank wall condition and the
glass-window condition is due to natural daylight vs.
artificial light, our data do provide evidence that actually
looking out the window plays a significant role in heart rate
Various theories have been advanced for why nature
views may be physiologically and psychologically restora-
tive. For example, according to attention restoration
theory (Kaplan & Kaplan, 1989), nature views have
properties that engage involuntary yet undemanding
attention, and thus promote recovery from mental fatigue.
Alternatively, according to one version of psycho-evolu-
tionary theory (Ulrich et al., 1991), many aspects of nature
accord in humans a quick positive affective reaction which
subsequently benefits physiological and psychological
processes. What is striking about our findings is that the
physiological and psychological experience of nature would
appear to differ depending on the medium (transparent
glass or digital display) through which one views nature.
Granted, the difference may be due to the lack of full
fidelity in the digitized real-time display; for example, the
plasma window did not afford parallax (the apparent
shifting of objects when viewed at different angles), a
difficult but tractable technical problem (Radikovic,
Leggett, Keyser, & Ulrich, 2005). But we suspect—and it
awaits further study—that the difference is due to more
complex reasons, involving not only technical issues of
parallax, pixilation, and 2-D as opposed to 3-D depth
perception, but judgments by viewers about what it means
for a view to be ‘‘real’’ as opposed to ‘‘represented,’’ and
how such judgments feed back into the physiological and
psychological system.
This study also speaks to the problem of the shifting
baseline. The problem is characterized well in the context
of the human–nature relationship by Fredston (2001) who,
over several decades, rowed more than 20,000 miles of
some of the wildest coastlines in the arctic waters. During
one of her later expeditions, she and her husband were
rowing along portions of Norway. She notes that much of
Norway’s built environment has an esthetic that most
towns in Alaska (where she lives) lack. But then she adds:
Still, even the undeniably beautiful portions of the
Norwegian coast that send visitors from more devel-
oped, congested parts of Europe into raptures seemed
sterile to usyThat experience frightened us to the
marrow. It made us realize that, like the perpetually
grazing sheep [in Norway], centuries of human habita-
tion have nibbled away not only at the earth but at our
perception of what constitutes nature. When we do not
miss what is absent because we have never known it to
be there, we will have lost our baseline for recognizing
what is truly wild. In its domestication, nature will have
become just another human fabrication (p. 217).
This problem of the shifting baseline takes on greater
import when one recognizes that not only are we quickly
degrading the natural world (and thus limiting our
opportunities to interact with healthy and diverse ecosys-
tems), but more and more the human experience of nature
will be mediated by technological systems. Of course,
humans will continue to adapt to such technologies. But it
is important to address the issue of whether such
adaptations are not just different but impoverished from
the standpoint of human functioning and flourishing, and
whether such technological systems and resulting interac-
tions are shifting the very baseline of what we can recognize
as impoverishment. The current study can be understood
as an initial foray into this largely uncharted territory; and
our results, even in this early stage, provide some
cautionary thoughts.
This material is based upon work supported by the US
National Science Foundation under Grant nos. IIS-
0102558 and IIS-0325035. Any opinions, findings, and
conclusions or recommendations expressed in this material
are those of the authors and do not necessarily reflect the
views of the National Science Foundation. We thank
Judith H. Heerwagen, Gordon H. Orians, and James
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... We acknowledge that previous research comparing actual and simulated nature views has reported that actual views are more restorative than their simulated counterparts (Frost et al., 2022;Kahn et al., 2008;Kjellgren & Buhrkall, 2010). Notably, Kahn et al. (2008) found that heart rate recovery from low-level stress was faster when participants had a glass window in the room than when they had a plasma display ''window'' of the same visual content visible through the glass window. ...
... We acknowledge that previous research comparing actual and simulated nature views has reported that actual views are more restorative than their simulated counterparts (Frost et al., 2022;Kahn et al., 2008;Kjellgren & Buhrkall, 2010). Notably, Kahn et al. (2008) found that heart rate recovery from low-level stress was faster when participants had a glass window in the room than when they had a plasma display ''window'' of the same visual content visible through the glass window. However, both virtual windows and existing windows might have health and work performance benefits (Han, 2020;Lottrup, Stigsdotter, Meilby, & Claudi, 2015;Pati, Harvey, & Barach, 2008). ...
... We believed that this goal aligns well with the real-world design implications of a window being opened in a busy café, since students would not normally be told to pay attention to a specific window during their visit. In fact, several other experiments of windows looking onto nature have not directed user's attention, tracked eye movements, or captured visual attention with self-reported data (i.e., Benfield et al., 2015;Li & Sullivan, 2016; though see also Kahn et al., 2008;Ulrich, 1984 effects of nature are attributable to microvisual exposures, longer durations of visual attention, and other nondirectional sensory inputs (sound and smell). ...
Exposure to nature can improve psychological well-being such as attention restoration. These restorative benefits may be provided by windows looking onto nature, yet studies on the restorative qualities of windows have largely taken place in calm environments where restoration demands are relatively low. Thus, the restorative effects of windows in busy environments warrant examination. This virtual reality (VR) experimental study measured the restorative qualities of windows with nature views in a busy setting. We exposed 88 undergraduate participants to an open, closed, or no window condition by creating a CAVE-like VR environment. The participants saw a 6-min wall-projected video of a busy university café along with indoor sounds played in the background and the scent of coffee created by an essential oil diffuser. Birdsongs and dirt smells were added to the open window condition. The Perceived Restorativeness Scale (PRS) and Restoration Outcomes Scale (ROS) were administered after VR exposure. Results showed that compared to no window, the open window was more restorative in terms of the ROS, PRS, and the PRS subscales related to fascination and being away. The closed window was more restorative in terms of the ROS and being away subscale. Unexpectedly, the addition of sounds and smells virtually coming through the open window did not provide restorative qualities beyond what was provided by the closed window. These findings provide suggestive evidence that virtual windows looking onto nature provide restorative effects for people in busy indoor environments.
... The primary drives for use of CGS were relaxing and socializing, thus agreeing with Gearin and Kahle (2006;and Foellmer, Kistemann & Anthonj, (2021). Researchers suggested that, use of the green spaces plays an important role in stress reduction (Kahn et al., 2008;Jim & Chen, 2006). The respondents using CGS as places for meeting and other social activities will lessen loneliness and increase social contact amidst themselves (Maas et al., 2009;Dyment & Bell, 2008). ...
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Green spaces are essential areas in the university campuses. Attractive green space areas are considered as features which contribute positively not only to the student experience but the image of the university. The study generated data from undergraduate students at Gombe State University, it reveals understandings about students' perceptions and use of campus green spaces (CGS). The quantitative data collected via the questionnaires were digitalized and analyzed using MS Excel statistic package. Descriptive statistics, including measures of percentage and frequency to analyze the associations between perceptions and use of CGS and students' well-being on campus. Content analysis was used to analyze qualitative data generated. The study results indicate that majority of respondents (94%) both use and aware of campus green spaces, and CGS are important for the image of the university and also an integral component of the campus environment. The campus aesthetic quality and its design and management style have impact on the perception and use of its green spaces. The students (73%) preferred areas with manicured gardens, seats, and lawns over those areas without these facilities. The study recommends that a university campus needs manifold forms of green spaces to satisfy the needs of increasing number of student users.
... The intent of excluding these types of nature was to focus on urban nature spaces one may intentionally visit to experience slightly "larger" urban nature. However, we recognize that there is a large body of literature examining the human benefits of urban street trees (e.g., Mullaney et al. [74], Seamans [75], and Taylor et al. [76]) and window nature views (e.g., Kahn et al. [77], Kaplan [78], Taylor et al. [79], and Ulrich [80]), as well as characterizing racial inequities in the accessibility of these types of nature within the US (e.g., Flocks et al. [81], Landry and Chakraborty [82], Li et al. [83]). Inequities in accessibility to urban street trees and window views of nature during the pandemic may be associated with changes in frequency of urban nature interaction. ...
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The COVID-19 pandemic has impacted everyone in urban areas. Some of these impacts in the United States have negatively affected People of Color more than their White counterparts. Using Seattle, Washington as a case study, we investigated whether inequitable effects appear in residents’ interactions with urban nature (such as urban green space). Using a 48-question instrument, 300 residents were surveyed, equally divided across four racial/ethnic groups: Asian, Black and African American, Latino/a/x, and White. Results showed that during the span of about 6 months after the onset of the pandemic, Black and Latino residents experienced a significant loss of time in urban nature, while Asian and White residents did not. The implications of these findings, including inequities in the potential buffering effects of urban nature against COVID-19 and the future of urban nature conservation, are discussed. Multiple variables were tested for association with the changes to time spent in urban nature, including themes of exclusion from urban nature spaces found throughout the existing literature. Findings show that decreases in time spent in urban nature among Black and Latino residents may be associated with their feeling as though they did not belong in urban nature. We provide recommendations based on these findings for how government agencies can promote more equitable access to urban nature during the pandemic and beyond. The results of this study have implications that extend beyond the US and are relevant to the international scholarly literature of inequities and urban nature interaction during the COVID-19 pandemic.
... The term "microrestorative experiences" was coined by Kaplan (1993) to suggest that even small and brief opportunities to disconnect (such as looking out a window at nature) are beneficial to workers. Organizations that acknowledge the value of, and provide regular access to, restorative environments are likely to improve employee wellbeing, performance, and effectiveness (Hernandez, 2007;Kahn et al., 2008;Kaplan, 1993;Nie et al., 2021;Sadick & Kamardeen, 2020). ...
Virtual reality is providing new opportunities for health and well-being, organizational learning, and tourism management. The study reported in this paper aims to examine whether engaging in a virtual reality tourism experience could function as a restorative intervention strategy to enhance mental well-being of employees in the workplace. The study employed a lab-based pre–post experimental design to test the effectiveness of a virtual reality tourism experience, involving a nature-based marine setting, to enhance mental restoration and reduce mental fatigue. The results show that 3 minutes of a virtual tourism experience can lead to enhanced concentration while boosting the mental well-being of employees, while, at the same time, providing destinations with an opportunity to promote “real” experiences.
... In this regard, one important issue to consider is whether virtual nature can elicit restorative effects similar to real nature. Some researchers have found that nature experiences mediated through technology is not as restorative as real nature experiences (Kahn et al. 2008), while others show that virtual nature experiences can be restorative (Liszio et al. 2018). In the present study, exposure to both virtual environments elicited fairly high levels of perceived environmental restorativeness, which were contrasted by qualitative reports referring to the virtual environments as artificial. ...
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Studies show that green exercise (i.e., physical activity in the presence of nature) can provide the synergistic psychophysiological benefits of both physical exercise and nature exposure. The present study aimed to investigate the extent to which virtual green exercise may extend these benefits to people that are unable to engage in active visits to natural environments, as well as to promote enhanced exercise behavior. After watching a video validated to elicit sadness, participants either performed a treadmill walk while exposed to one of two virtual conditions, which were created using different techniques (360° video or 3D model), or walked on a treadmill while facing a blank wall (control). Quantitative and qualitative data were collected in relation to three overarching themes: “Experience,” “Physical engagement” and “Psychophysiological recovery.” Compared to control, greater enjoyment was found in the 3D model, while lower walking speed was found in the 360° video. No significant differences among conditions were found with respect to heart rate, perceived exertion, or changes in blood pressure and affect. The analysis of qualitative data provided further understanding on the participants’ perceptions and experiences. These findings indicate that 3D model-based virtual green exercise can provide some additional benefits compared to indoor exercise, while 360° video-based virtual green exercise may result in lower physical engagement.
Background Benefits of green spaces on stress reduction have been shown in previous studies. Most existing studies to date have focused on the general population. However, there is a lack of understanding of physiological mechanisms underlying the beneficial effects of green space among special populations, such as pregnant women. Objectives To examine physiological and affective responses to green space on stress recovery among pregnant women, using simulated green space exposure through virtual reality (VR). Methods We recruited 63 pregnant women between 8 and 14 weeks’ gestational age for a laboratory experiment. Participants were randomly assigned to view one of three, 5-min, VR videos of an urban scene with different green space levels (i.e., non-green, moderate, and high) after a laboratory stressor, the Trier Social Stress Test. Physiological stress responses were measured via changes in blood pressure, heart rate, skin conductance level, salivary alpha-amylase, and salivary cortisol. Affective response was measured using the Positive and Negative Affect Scale. Results We found that visual exposure to a green space environment in VR was associated with both physiological and affective stress reduction among pregnant women, including lower systolic blood pressure [-4.6 mmHg, 95% confidence interval (CI): −8.8, −0.4], reduced salivary alpha-amylase concentration (−1.2 ng/ml, 95% CI: −2.2, −0.2), improved overall positive affect (score: 6.6, 95% CI: 0.3, 13.0) and decreased negative affect of anxiety (score: −2.6, 95% CI: −5.19, −0.04) compared to non-green space environment. Exposure to high green space environment in park-like setting had the strongest impacts on stress recovery. Conclusion This study demonstrated that virtual green space exposure could effectively ease stress and improve mental health and well-being during pregnancy. Even a short immersion in VR-based green space environment may bring health benefits, which has significant implications for pregnant women when access to an actual nature may not be possible.
Two studies tested the hypothesis that exposure to a small dosage of immersive nature using virtual reality (VR) enhances connectedness to nature (CN) and changes affective states among those with a low level of CN at baseline. In Study 1, participants (N = 31) perceived a three-session (10 minutes each) virtual nature intervention as restorative and saw a significant and progressive increase in their CN as well as a decrease in negative affect. CN was significantly associated with enjoyment of nature and motivation for future nature engagement. In Study 2, participants (N = 80) were randomly assigned to either a two-session (6 minutes each) virtual nature intervention or a control condition in which they were immersed in a virtual urban environment of the same duration as the treatment group. Exposure to virtual nature was perceived as more restorative than virtual urban and resulted in a greater improvement in CN. The intervention group reported more enjoyment of nature and greater motivation for future nature engagement compared with virtual urban. The effect on affective states was mixed.
In the open-plan workspace, which has grown to more than 70% of all offices in the United States, openness and flexibility came at the cost of personal environmental control. Recent evidence has shown a decrease in worker satisfaction due to the lack of privacy and increased noise level and distraction. In this paper, we present a vision for using context-aware multimodal augmentation to improve productivity and well-being in the open-plan office. We introduce the Mediated Atmosphere Table (MAT) — a workstation combined with a network of custom environmental control devices (lighting, audio, video, airflow, heating, and scent) to alter the user’s local environment and to improve the restorative quality of the user’s personal space in the open-plan office. A preliminary user study (N=38) examined the effect on stress development based on subjective measures of perception, as well as objective measures extracted from recordings of heart rate variability. Our findings show that MAT significantly (p<0.05) affects occupants’ perception, as well as their physiological response in an open-plan research workspace. Furthermore, we found a significant difference between experimental conditions with and without scent. We provide an exploratory look at the effect of scent and the applications of MAT.
Objective This study examined the influences of healthcare facility interior features on users’ wayfinding performance and the relationship between stress and wayfinding. Background General hospitals in China always present significant wayfinding problems due to their sizes and complexity. Poor wayfinding often leads to a frustrating and stressful user experience. It has not been fully understood how hospital indoor features affect wayfinding and whether an individual’s stress levels are associated with wayfinding performance. Method We conducted an experiment in which 117 college students, aged 18–33 ( M = 21.88, SD = 3.01), performed two tasks in virtual reality environments of outpatient clinics. Stress (skin conductance response) and wayfinding performance (distance ratio and time ratio) were measured. Participants’ sense of orientation, navigation ability, distance estimation, and spatial anxiety were captured by a survey. Results Male participants reported a significantly better sense of orientation and less spatial anxiety than females. Participants’ stress levels were lower with outdoor window views compared to those without outdoor views. With more environmental features (landmarks and outdoor window views) added to the environments, participants showed significantly better wayfinding performance. No significant relationship was found between wayfinding performance and participants’ stress levels in this study. Conclusion While individual environmental factors might not have a significant influence, combining multiple elements such as window views and landmarks could lead to better wayfinding performance. More research is needed to examine the relationship between stress and wayfinding.
This study examined preschool children's reasoning about and behavioral interactions with one of the most advanced robotic pets currently on the retail market, Sony's robotic dog AIBO. Eighty children, equally divided between two age groups, 34-50 months and 58-74 months, participated in individual sessions with two artifacts: AIBO and a stuffed dog. Evaluation and justification results showed similarities in children's reasoning across artifacts. In contrast, children engaged more often in apprehensive behavior and attempts at reciprocity with AIBO, and more often mistreated the stuffed dog and endowed it with animation. Discussion focuses on how robotic pets, as representative of an emerging technological genre, may be (a) blurring foundational ontological categories, and (b) impacting children's social and moral development.
This chapter presents analytic methods for matched studies with multiple risk factors of interest. We consider matched sample designs of two types, prospective (cohort or randomized) and retrospective (case-control) studies. We discuss direct and indirect parametric modeling of matched sample data and then focus on conditional logistic regression in matched case-control studies. Next, we describe the general case for matched samples including polytomous outcomes. An illustration of matched sample case-control analysis is presented. A problem solving section appears at the end of the chapter.
Research and teaching in environmental health have centered on the hazardous effects of various environmental exposures, such as toxic chemicals, radiation, and biological and physical agents. However, some kinds of environmental exposures may have positive health effects. According to E.O. Wilson’s “biophilia” hypothesis, humans are innately attracted to other living organisms. Later authors have expanded this concept to suggest that humans have an innate bond with nature more generally. This implies that certain kinds of contact with the natural world may benefit health. Evidence supporting this hypothesis is presented from four aspects of the natural world: animals, plants, landscapes, and wilderness. Finally, the implications of this hypothesis for a broader agenda for environmental health, encompassing not only toxic outcomes but also salutary ones, are discussed. This agenda implies research on a range of potentially healthful environmental exposures, collaboration among professionals in a range of disciplines from public health to landscape architecture to city planning, and interventions based on research outcomes.
This article investigates the direct and indirect effects of windows in the workplace onjob satisfaction, intention to quit, and general well-being. The impact of three specific influencing mechanisms are examined: general level of illumination, sunlight penetration, and view. The extent to which these environmental features might moderate the negative consequences of job stress is investigated. The sample consisted of 100 white-and blue-collar workers who were employed in a large wine-producing organization in the Mediterranean region of Southern Europe. The results showed a significant direct effect for sunlight penetration on job satisfaction, intention to quit, and general well-being. A view of natural elements (i.e., trees, vegetation, plants, and foliage) was found to buffer the negative impact of job stress on intention to quit and to have a similar, albeit marginal, effect on general well-being. No effects for general level of illumination were found.