Labyrinth Nature Walk in VR for Stress Reduction Therapy

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



Rui Yang Department of Electrical and



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.

Permission to make digital or hard copies of part or all of this

work for personal or classroom use is granted without fee

provided that copies are not made or distributed for profit or

commercial advantage and that copies bear this notice and the

full citation on the first page. To copy otherwise, to republish, to

post on servers or to redistribute to lists requires specific

permission and/or a fee. HIT2018, Vancouver, BC, Canada.

© 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

2

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.


4

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


6

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

Labyrinth Nature Walk in VR for Stress Reduction Therapy

Documents

Transcript of Labyrinth Nature Walk in VR for Stress Reduction Therapy