Labyrinth Nature Walk in VR for Stress Reduction Therapy
Heather Borgard Department of Electrical and
Computer Engineering University of British Columbia
Vancouver, BC V6T 1Z4 [email protected]
Hoda Sadat Hashemi Department of Electrical and
Computer Engineering University of British Columbia
Vancouver, BC V6T 1Z4 [email protected]
Rui Yang Department of Electrical and
Computer Engineering University of British Columbia
Vancouver, BC V6T 1Z4 [email protected]
ABSTRACT
As cities become more populated, residents can experience
stress and depression more easily and have less opportunities
to benefit from a natural walking environment. The idea of
using VR for therapy has shown promise for reducing anxiety
disorders, PTSD, and even phobias. This project, Labyrinth
Virtual Walk, is mainly targeted on designing a VR
environment to help reduce stress and enhance pedestrians’
walking experience in cities. We integrated a labyrinth, a
pattern used for meditation therapy, and a natural
environment into a VR interface. We ran within-subjects
experiments on users of the VR interface to compare a
labyrinth path (specific meditative pattern) with a straight
path (no specified pattern). Participants’ heart rates and blood
pressures were measured as the indicator of their stress level,
and we used a questionnaire and a final interview to collect
nonparametric data regarding satisfaction and feedback of our
interface. The average sum of diastolic and systolic blood
pressure was reduced by 0.5% after using the straight path
interface, and by 1.6% after using the labyrinth interface.
Although the differences between the labyrinth and straight
path walk were not statistically significant, we found that 66%
of participants preferred the environment with a labyrinth
pattern. In addition, they experienced an overall positive
mood change and provided positive feedback on our interface
design.
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© UBC 2018
KEYWORDS Virtual Reality, Labyrinth Walk, Meditation, Stress Therapy
1 INTRODUCTION
Among all kinds of human emotions, stress is one that
particularly deserves attention, because it has a strong link to
an individual’s physical and mental health. According to
Mental Health America, over 21% of American adults (42.5
million) are affected by anxiety disorders each year. Major
depression is one of the most common mental illnesses,
affecting 6.7% (more than 16 million) of American adults in a
given year [1]. Some researchers explored different factors in
the environment that can contribute to stress, depression, and
an overall negative mood affectation. Conversely, others have
discovered factors (especially in nature) that can contribute to
positive mood affectation including a sense of serenity,
mindfulness, and positivity.
As urbanization increases, many individuals have daily walks
along urban routes where noise, crowds, and cars can all be
negative contributing factors to their daily mood. Previous
research has shown that walking a labyrinth, a meandering
path that is often unicursal, with a singular path leading to a
center [2] and walking in a natural environment both have
calming and stress-relieving effects on the human mind and
body. Based on these theories, we developed Labyrinth Virtual
Walk, a wearable interface using Google Cardboard, a
smartphone, and a pair of earphones to enhance pedestrians’
walking experience in the city. Our main contributions are
listed as follows:
1. Complete the concept, design and implementation of a
special VR walking interface.
2. Explore the research area of VR labyrinth walk combined
with the natural scenes for stress reduction.
3. Provide further applications on the interface towards
reducing stress and/or creating positive mood changes.
HIT’18, April 2018, Vancouver, BC Canada H. Borgard, H. Hashemi, R. Yang
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2 BACKGROUND AND RELATED WORK
2.1 VR Therapy
With the development of VR technology, researchers have
started to pay attention to its application for mental health
therapy in recent years. In 2013, Clara Suied et al from Institut
de Recherche Biome ́dicale des Arme ́es (IRBA) suggested that
auditory-visual VR is a promising diagnostic and therapeutic
tool for cynophobia [3]. Since 2016, several VR applications
have been developed and released to assist with meditation.
Currently, the military uses VR for Post-traumatic stress
disorder (PTSD) treatment. There has also been research
using VR specifically for the stress-reduction therapy. One
such study [4] developed a VR system designed for chronic
pain patients to learn mindfulness-based stress reduction. The
system used biofeedback sensors to obtain galvanic skin
response (GSR) from user sitting in a room, and changed the
VR scene based on the received data. Another study [5] used
VR to improve the exercise quality and measured heart rate
and walking speed to compare the VR nature condition with
the real nature walk. In one study, virtual reality and
neurofeedback were combined to design a computer-assisted
meditation system [6]. Their system measured users’ brain
activity via EEG and estimated the levels of concentration and
relaxation.
2.2 Labyrinth
During the past two decades, patients experiencing
depression, anxiety, and life transitions have found the
labyrinth to be helpful as an adjunctive part of psychotherapy
with their therapists [7]. Largely due to the effort of Reverend
Dr. Lauren Artress, the Voice of the Labyrinth Movement in
San Francisco, labyrinths are now appearing in churches,
schools, parks, and medical centers across the country. There
are currently more than 1,000 labyrinths in the United States,
with more than 50 labyrinths in Texas and more than 125 in
California [8]. A common response enlivened in a labyrinth
walk is one of transformation or renewal. Looking at the
labyrinth pattern, many walkers feel a sense of connection
within the self, between inner and outer, and between past
and future. They are encouraged to find their own natural
pace as they walk and find themselves settling into a rhythmic
movement. The intent is to evoke physiological, affective, and
spiritual outcomes similar to a sitting meditation [8].
2.3 Nature Walk
In addition to labyrinth-walking based therapy, nature/forest
walking is another effective stress relieving method. In Japan,
shinrin-yoku, meaning forest bathing, was first proposed in
1980s and has since become a recognized relaxation activity.
It included meditating and/or walking in forests, in order to
promote physiological and psychological health by breathing
in the volatile substances released by trees. Another study [9]
revealed that forest environments are advantageous with
respect to acute emotions, especially among individuals
experiencing chronic stress. It has also been researched that
forest bathing could improve mood and induce a feeling of
subjective restoration and vitality [10]. We believe that adding
a natural background to a labyrinth can strengthen the
soothing effect similar to meditation and improve a user’s
mood.
3 Interface Design
3.1 Theoretical Background
A multitude of studies have been conducted to investigate
which factors or elements during a nature/forest walk help
foster human health. Out of numerous articles ranging from
2006 to 2015, Hassen et al [11] summarized seven indicators
of quality of green space associated with mental health and
well-being: (1) biodiversity/species richness; (2) aesthetics of
green space; (3) sound levels/noise; (4) facilities: availability
and condition; (5) safety; (6) presence of blue spaces/water
features; and (7) visual stimuli/design/landscape style.
Furthermore, Maas et al [12] found that the amount of
agricultural and natural green in the living environment was
positively related to perceived general health.
In addition, we conducted a preliminary questionnaire to
collect more data about typical stressors daily walkers
experience. The result shows that users have preferences
regarding routes that can contribute to stress or relieve stress.
We found most users felt that dark, crowded routes
contributed to stress while daylight and “good” weather along
routes decreased stress. These preferences combined with
previous studies set the basis for environments we want to
mimic visually and auditorily to convey a positive emotional
response from the user. For example, due to the preference of
well-lit areas, we created a scene set during the daytime and
play sounds that occur during this time period.
3.2 Device Our design is a wearable interface including a VR headset and
headphones that present an immersive labyrinth walking
experience in a natural environment for pedestrians walking
in a city. The name of our interface is Labyrinth Virtual Walk.
It is a visual simulation through a smartphone and Google
Cardboard headset. We have purchased Google Cardboard V1
combined with a head strap to be mounted on the user’s head
comfortably (Figure 3). For the visual display, we provided an
android smartphone system with the design already installed
and use the same forest visual characteristics for each subject.
3
Figure 1: Google Cardboard V1 combined with head strap
In addition to a visual VR experience, we have provided
acoustics to add to the immersive quality of the simulation.
We have used headphones to play the same music (tranquil
nature sounds typically found in forests during daytime) for
each scene.
3.3 VR Design
We made two walk path designs in our interface. The first
design is a straight path with four 90 degree turns (Figure 2).
Figure 3 shows the second path outlined by a labyrinth
pattern. Both paths are framed by grass and both have the
same natural characteristics (trees, mountains, clouds, sky).
We constructed VR Scene using Unity 2017.3 and GoogleVR
1.130.1 Development Toolkit. A C# Script has been
implemented in Unity that allows the user to “walk” in VR.
When the users tilts the apparatus toward the ground at a
certain angle, it will trigger the simulation to move forward in
space at a specified speed. Based on the results of the
preliminary test and pilot test, we chose to use a speed of 3
and toggle angle of 20 for the experiment. The straight path
simulation is a loop so the total time, speed, and toggle angle
will all be consistent with these labyrinth variables. The user
and stereoscopic view of the scene is shown in Figure 4.
Figure 2: Straight walk scene. Left: Top-down view of terrain, Right: First person view of simulation
Figure 3: Labyrinth walk scene. Left: Top-down view of terrain, Right: First person view of simulation
Figure 4: Stereoscopic view of prototype and user interacting with the device during the experiment
4 User Study
4.1 Research Question
The user study is aimed to answer the following questions:
1. Will the combination of a labyrinth and natural
environment in VR help reduce stress in individuals?
2. Is there any difference in stress level by the addition of a
labyrinth path in a natural VR environment?
3. Does this interface have additional applications for reducing
stress than walking around the city?
4.2 User Study Methods
We performed an initial pilot test of one male and one female
participant to receive feedback on Labyrinth Virtual Walk and
to troubleshoot problems with our experimental design. For
the user study, we recruited 3 male and 3 female graduate
UBC students in the age range of 20 to 27. We selected a
clearing surrounded by Thunderbird Blvd and Thunderbird
Crescent as our experiment site. The lawn has an area of
approximately 100 square meters. The relatively soft tactility
of a lawn facilitated the immersive experience of walking in a
forest.
HIT’18, April 2018, Vancouver, BC Canada H. Borgard, H. Hashemi, R. Yang
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Initially, each participant was given a brief introduction of the
user test and Labyrinth Virtual Walk. We prepared each
participant for two conditions of experiments by leading them
to the experiment site, teaching them how to use the interface,
and taking initial measurements with a smart watch. With
each study, we recorded vitals (blood pressure and heart rate
variability) immediately before and after the participant
walked the route. The block diagram of the experimental
design is demonstrated in Figure 5.
We ran two conditions of the experiments for each participant
and arranged pre-stressing tasks (watching a video involving
extreme heights) before each phase.
For the first condition, the VR scene consisted of a natural
forest aesthetic with trees, grass, and a green pathway. The
path was straight with four 90 degree turns. The user walked
in the scene for the designated time limit of 5 minutes. For the
second condition, the VR scene also consisted of a natural
forest aesthetic with trees, grass, and a green pathway.
However, the path included a labyrinth pattern that the user
followed for the time limit of 5 minutes. After the participant
had completed a phase, they were given a questionnaire
regarding the interface to draw on the user satisfaction
information. An interview session about their overall
experience using Labyrinth Virtual Walk was carried out at
the end of the user test to collect feedback and compare the
two path designs.
Figure 5: Block diagram of experimental design
4.3 Data Collection and Analysis
We collected both qualitative and quantitative data from
users. The quantitative data included measurements of heart
rate and static blood pressure (systolic and diastolic). We used
a smartwatch to measure these vitals. Previous research [13]
showed that cardiovascular changes are representative of
acute psychological stress and can be measured through
noninvasive vital signs such as blood pressure and heart rate.
We measured the vital signs in the user rest condition as
initial values. Every new value obtained during and after
experiment was divided by initial values to have normalized
measurements for each individual. These normalized values
were summed together as a final metric for stress assessment.
The qualitative data included questionnaire responses to
Likert scale questions (5 scale) regarding the labyrinth and
straight paths as well as responses in a post interview
comparing the two designs.
4.3.1 Data Collection and Analysis
The physiological response results of the straight path walk
and labyrinth experiments before normalizing are
demonstrated in Table 1. The pre-stressing task increased
average blood pressure, however, it did not increase heart
rate for all the subjects. The sum of diastolic and systolic blood
pressure was reduced by 0.5% after using the straight path
interface, and by 1.6% after using the labyrinth interface. This
suggested that the labyrinth interface was more effective than
the straight path walk in stress reduction with regards to
changes in blood pressure. On the other hand, the heart rate of
participants remained approximately constant after both
experiments.
Since our experiment contains one within-subjects factor, we
analyzed stress level and satisfaction data and tested our
hypothesis by running repeated measures ANOVA (omnibus F
test) on SPSS. Along with statistical significance (computed
using alpha = .05), we report partial η of effect size and power.
To interpret effect size, .01 is a small effect size, .06 is medium,
and .14 is large [14]. Regarding the sum of the normalized
vital measurements as an indicator for the stress level, the
difference between the two interfaces is non-significant (F
(1,5) = .000, p = .992, 𝜂2 = .000). For both the straight path and
labyrinth path designs, the vital differences before and after
the walk are also nonsignificant (straight: F (1,5) = .335, p =
.588, 𝜂2= .063; labyrinth: F (1,5) = .226, p = .654, 𝜂2= .043)
possibly due to the fact that the effect size and power are
relatively low in this experiment.
Table 1: Heart Rate and Blood Pressure Results
4.3.2 Analysis of Qualitative Results
We collapsed the answers of Likert scale questions from the
questionnaires for both interfaces on satisfaction, usability,
design novelty, relaxation effect, scene attractiveness, and
preference between the scene and a city environment. We also
took into account ratings of motion sickness and fatigue level
to make comparisons and compared each of these items
separately, as shown in Table 2. A reliability analysis showed
that they were likely measuring the same construct
(Cronbach's alpha = .668). Wilcoxon sign-rank test was used
as our nonparametric test, which shows no significance
between interfaces containing a straight path and a labyrinth
5
path (Z=-.314, p<.753), possibly due to low statistical power.
Table 2 shows the Wilcoxon Signed Ranks Test result of the
answers to individual questions, where straight path is
denoted as s and labyrinth path as l.
Table 2: Statistics of Wilcoxon Signed Ranks Test. b: The
some of negative ranks equals the sum of positive ranks, c:
Based on negative ranks, d: Based on positive ranks.
Among all the valuable feedback we collected from the short
interview with participants, two thirds of them preferred the
interface with a labyrinth incorporated in the scene. There
were three central viewpoints. First, participants generally
provided positive feedback for Labyrinth Virtual Walk design
overall. They “enjoyed the interface and the audio element,”
which “added to the relaxation of the scene,” they “liked the
scene and overall experience of VR,” and they “felt
comfortable walking around our test site in reality.”
Supporters of the labyrinth path reasoned that it was more
interesting than the straight path. Many felt “the straight path
was boring/mundane with no interesting rotations” and some
expressed “the straight path seemed scary, isolated, and
deserted” as the major weaknesses of the straight path. The
summary of user feedbacks is shown in Figure 6. In addition,
some participants met a few difficulties when using our
interface and offered their suggestions. For example, several
participants expressed that they ”got stuck at one point using
the labyrinth and could not move forward,” and some stated
that “rotation during walking made it difficult to turn.” These
are most likely technical issues related to the camera in Unity,
a feature that would ultimately be fixed in a later prototype.
One participant suggested “adding smells and more sensory
clues would have added to the VR experience to make it more
immersive”, which would be a direction of improvement for
us. Finally, several participants suggested other interesting
and novel ways to use Labyrinth Virtual Walk for relieving
stress, which opened up some new research area ideas for us.
One participant had the idea that our interface “could be used
as an escape or in a hospital to let kids immerse themselves in
a fun VR world while they got a shot or difficult procedure”,
another one proposed that “this interface would be well-
suited for walking around at night and encouraging people to
exercise as when you stops walking, you feel motion sickness.”
Though our quantitative data doesn’t show statistically
significant improvement with respect to vital measurements,
many participants approved the utility of Labyrinth Virtual
Walk and stated that the prototype “feels immersive.”
Figure 6: User Feedback Diagrams
5. Discussion
Although the differences between the two walking environments were not statistically significant, based on the average vital decrease and interview results, we see a tendency of stress relief after using Labyrinth Virtual Walk and a general preference towards the environment with a labyrinth pattern. There were various complications during the course of this experiment that may have affected the final outcome. First of all, we noticed that for some participants, the measurements of their heart rate and blood pressure show a decrease after completing the prestressing task which was meant to increase these vitals. There are two factors that may have contributed to this phenomenon. For one thing, the participants’ vitals may increase after making their way to the experiment site. Having them rest longer after arriving may have resulted in lower initial heart rate and blood pressure, which would have likely been more accurate resting measurements. Second, the personal response to the stressor that we employed for the prestressing task turned out to be highly subjective. Therein lies the difficulty in choosing an appropriate task for pre-stressing of this experiment. For the pilot test, we used a high-intensity typing program and found this task not effective for everyone. For the user test, we utilized videos of first-person extreme heights, which has been shown to cause physiological arousal in previous studies [15]. This change was not a great improvement, as seen by our vital measurement results and expressions of our participants finding the videos to be only “interesting.”
We also had some errors resulting from the smartwatch measurement. Due to the time delay the device has when recording (approximately 40 seconds in total for recording both two vitals), we couldn’t acquire the vital measurements just before and after using our interface, thus we couldn’t determine the effect of Labyrinth in Nature Walk as precisely. Furthermore, smartwatches are intended to be used as a personal device, often normalizing data to fit one individual, which is not ideal for multi-person measurements. As a result, the accuracy of our data might be compromised. Even though
HIT’18, April 2018, Vancouver, BC Canada H. Borgard, H. Hashemi, R. Yang
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we utilized individual information including height, weight, and age for each participant (these values were not recorded and used solely for normalizing the smart watch measurements), we could not account for the smart watch automatically adjusting/calibrating for differences in skin tone, temperature, position on the arm, and wrist width. Ideally for this type of study, we would have used an EKG and manual blood pressure cuff to ensure individual accuracy and to record all variability of the participants’ cardiac physiology. However, for the purposes of this particular experiment, it made sense to use a simple, portable device which could give relatively quick results right after the participant used our interface outdoors. Future work on this project would benefit from extensive physiological measurements to ensure the validity of the individuals’ stress response.
Finally, motion sickness and fatigue are also factors that have an impact on the vitals. As participants spent longer time in VR, they could experience more motion sickness effects, which may counteract the calming response of Labyrinth Virtual Walk and result in biased measurements. Not everyone reacts to virtual reality the same way and one of our participants expressed that they had never used a VR interface before.
6. Conclusion and Future Directions
In this study, we explored the possibility of using self-
designed virtual reality application with nature sounds to help
pedestrians relieve stress when walking in a city. We
investigated the stress-reducing effect labyrinths and a
natural environment have on individuals by running a within-
subjects experiment with two conditions in our user test. The
results showed that after using the straight path interface, the
average sum of diastolic and systolic blood pressure was
reduced by 0.5%, and while after using the labyrinth interface,
by 1.6%. We found that the labyrinth path was generally
preferred by the participants, though the difference between
the labyrinth and straight path walk were not statistically
significant when ran in the hypothesis test. In the interview,
the participants expressed experiencing positive mood
changes overall and provided positive feedback to our
interface design. Further work on Labyrinth Nature Walk
would include reworking the scene in Unity to create more
immersion, better functionality, and removal of negative
attributes like feelings of isolation. Based on the feedback we
received, we would extend the character controller height so
the user can see more of the overall terrain, include animals or
sense of community to combat isolation feelings, and create
more interesting paths and scenery like bodies of water.
Labyrinth Nature Walk creates a wide range of possibilities by
offering individuals refuge from a stressful or unpleasant
environment into a calm serenity. Future work in this realm
could explore additional applications. For example, this VR
world could allow children to remain calm during a shot or
difficult procedure in the hospital. Other applications we
considered when receiving feedback from participants are
encouragement of exercise programs or even integrated into a
car’s augmented reality windshield to be used during long
commutes or when stuck in traffic.
ACKNOWLEDGMENTS We would like to thank Dr. Sidney Fels and Qian Zhou for their
valuable suggestions and assistance in formulating this
project.
REFERENCES [1] Mental Health America. (1970, January 01). Retrieved from
http://www.mentalhealthamerica.net/ [2] Rhodes, J., & Rudebock, C. (2006). Bibliography of Articles and Studies Related to Labyrinth Research. 1-48. Retrieved from https://zdi1.zd-cms.com/cms/res/files/382/Bibliography_of_Studies_Related_to_Labyrinth_Research_.pdf_517K.pdf. [3] Suied, C., Drettakis, G., Warusfel, O., & Viaud-Delmon, I. (2013). Auditory-visual virtual reality as a diagnostic and therapeutic tool for cynophobia. Journal of Cybertherapy and Rehabilitation, 16(2), 145-152. [4] Gromala, Diane, Xin Tong, Amber Choo, Mehdi Karamnejad, and Chris D. Shaw. "The virtual meditative walk: virtual reality therapy for chronic pain management." In Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems, pp. 521-524. ACM, 2015. [5] Calogiuri, Giovanna, Sigbjørn Litleskare, Kaia A. Fagerheim, Tore L. Rydgren, Elena Brambilla, and Miranda Thurston. "Experiencing Nature through Immersive Virtual Environments: Environmental Perceptions, Physical Engagement, and Affective Responses during a Simulated Nature Walk." Frontiers in Psychology 8 (2017): 2321. [6] Kosunen, Ilkka, Mikko Salminen, Simo Järvelä, Antti Ruonala, Niklas Ravaja, and Giulio Jacucci. "RelaWorld: neuroadaptive and immersive virtual reality meditation system." In Proceedings of the 21st International Conference on Intelligent User Interfaces, pp. 208-217. ACM, 2016. [7] Hong, Y. J., & Jacinto, G. A. (2012). Reality therapy and the labyrinth: A strategy for practice.Journal of Human Behavior in the Social Environment, 22(6), 619-634. 10.1080/10911359.2012.655561 [8] Sandor, M. K., & Froman, R. D. (2006). Exploring the effects of walking the labyrinth. Journal of Holistic Nursing, 24(2), 103-110. 10.1177/0898010105282588 [9] Morita, E., Fukuda, S., Nagano, J., Hamajima, N., Yamamoto, H., Iwai, Y., . . . Shirakawa, T. (2007). Psychological effects of forest environments on healthy adults: Shinrin-yoku (forest-air bathing, walking) as a possible method of stress reduction. Public Health, 121(1), 54-63. 10.1016/j.puhe.2006.05.024 [10] Takayama, N., Korpela, K., Lee, J., Morikawa, T., Tsunetsugu, Y., Park, B., . . . Kagawa, T. (2014). Emotional, Restorative and Vitalizing Effects of Forest and Urban Environments at Four Sites in Japan. International Journal of Environmental Research and Public Health,11(12), 7207-7230. doi:10.3390/ijerph110707207 [11] Hassen, N., & desLibris - Documents. (2016). Influence of green space on mental health Wellesley Institute. [12] Maas, J., Verheij, R. A., Groenewegen, P. P., Vries, S. d., & Spreeuwenberg, P. (2006). Green space, urbanity, and health: How strong is the relation? Journal of Epidemiology and Community Health (1979-), 60(7), 587-592. 10.1136/jech.2005.043125 [13] Wright, B. J., Obrien, S., Hazi, A., & Kent, S. (2014). Increased systolic blood pressure reactivity to acute stress is related with better self-reported health. Scientific Reports, 4(1). doi:10.1038/srep06882 [14] Cohen, J. Eta-squared and partial eta-squared in communication science. Human Communication Research 28, (1973), 473–490. [15] New Findings Reported from University of Munich Describe Advances in Anxiety and Stress (Fear and physiological arousal during a virtual height challenge-effects in patients with acrophobia and healthy controls). (2016, February 22). Mental Health Weekly Digest, 144 Retrieved from http://link,galegroup.com/apps/doc/A443836380/HRCA?u=ubcolumbia&sid=HRCA&xid=123ad167
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