Contents lists available atScienceDirect
Urban Forestry & Urban Greening
journal homepage:www.elsevier.com/locate/ufugBeyond restorative benefits: Evaluating the effect of forest therapy on
creativity
Chia-Pin (Simon) Yu
a,b,*, Hsuan Hsieh
aaSchool of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan (ROC) bT.H. Chan School of Public Health, Harvard University, Boston, MA, USA
A R T I C L E I N F O
Editor: Matilda van den Bosch.
Keywords:
Forest therapy Restorative benefits Emotions
Nature and creativity
Chinese word remote associates test (CWRAT)
A B S T R A C T
This study had three purposes: (1) assessing physiological and psychological responses of a 3-day forest therapy workshop, (2) evaluating the effects of the forest therapy workshop on creativity, and (3) examining the re-lationship between change in emotions and improvements in creativity. We employed a within-subject design in the current study and recruited 23 participants from the attendees of the 2018 Da’an Forest Therapy Workshop in Taiwan. Physiological responses, heart rate, systolic blood pressure, and diastolic blood pressure were re-corded, and participants’ emotional states were measured. Furthermore, the Chinese Word Remote Associates Test (CWRAT) was used as the indicator of creativity. The study findings indicated the 3-day forest therapy workshop contributed to participants’ physical and mental health by regulating physiological responses as well as increasing positive emotions and reducing negative emotions. In regards to the creativity enhancement, the forest therapy workshop improved participants’ creative performances by 27.74 %, which indicates forest therapy is beneficial for high-level cognitive functioning. Moreover, we noted the change in creativity correlated significantly and negatively with change in the confusion–bewilderment emotion. This result indicates alle-viation of confusion–bewilderment correlates with enhancement of creativity. In this study creativity en-hancement was quantified in the forest therapy workshop, and an approach for measuring creativity in forest therapy studies was provided. This study extends typical stress-recovery forest therapy research by investigating high-level cognitive functioning (e.g., creativity). The contribution of this study is in the use of the creativity task in a forest therapy study, in addition to comparing the changes in creativity to changes in different aspects of mood.
1. Introduction
Urbanization, technological advancements, congested urban spaces, and fast-paced lifestyles have reduced the amount time people spend in natural environments. Studies have discovered people now spend 90 % of their lives indoors (Evans and McCoy, 1998). This trend has influ-enced the relationship between humans and nature. Moreover, city lifestyles have been reported to induce negative emotions, such as panic, anxiety, and depression (Dye, 2008). An increasing number of urban residents experience mental and physical health problems, such as depression and hypertension (Dye, 2008;Vining et al., 2008). Re-searchers suggest contact with nature is conducive to reducing physical and mental stress (Lee et al., 2012;Hartig et al., 1991,2014;Kaplan, 1995;Ulrich et al., 1991). Natural environments reduce the number of sensory stimuli, minimize possible exposure to stressors, and provide adaptive resources, which are required for adaption to stress in life.
Empirical studies have suggested urban green spaces can alleviate noise pollution from congested roads (Nilsson and Berglund, 2006), that plants can conceal unattractive structures in cities (Smardon, 1988), and that plants around a house may increase perceptions of privacy and reduce the sense of congestion for the residents of the house (Day, 2000).Kondo et al. (2018)review illustrated how a variety of physio-logical responses may be improved through different types of nature exposure (e.g. nature viewing, outdoor walks, outdoor exercise and gardening), while other empirical research has demonstrated physical health improvements, such as lowering heart rate, blood pressure and cortisol, as a result of exposure to nature (Hansmann et al., 2007;Lee et al., 2011,2014;Ochiai et al., 2015a,b;Ottosson and Grahn, 2005; Van den Berg and Custers, 2011;Yamaguchi et al., 2006). These re-ductions indicate natural environments substantially reduce sympa-thetic nervous system activity, increase parasympasympa-thetic nervous system activity, and alleviate mental strain, which is why people tend to
https://doi.org/10.1016/j.ufug.2020.126670
Received 2 October 2019; Received in revised form 23 March 2020; Accepted 24 March 2020 ⁎Corresponding author at: No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (R.O.C.).
E-mail addresses:simonyu@ntu.edu.tw,simonyu@hsph.harvard.edu(C.-P.S. Yu),mandyhsieh123@gmail.com(H. Hsieh).
Available online 02 April 2020
1618-8667/ © 2020 Elsevier GmbH. All rights reserved.
feel comfortable and relaxed in natural environments. Converging re-search highlights the benefits on health and well-being of interacting with nature. Accordingly, the idea of reconnecting with nature has been promoted by scholars (Balmford and Cowling, 2006;Saunders, 2003). In several Asian countries (e.g., Taiwan, Japan, and Korea), forest therapy is a popular and cost-effective approach for health promotion and is widely promoted by the government. The term “forest therapy,” derived from “Shinrin-yoku” (taking in the atmosphere of the forest or, literally, “forest bathing”), highlights the medically proven effects of exposure to forests (Ochiai et al., 2015b, p. 2533). In Korea, forest therapy is defined by law as “immune-strengthening and health-pro-moting activities utilizing various elements of the forest, such as fra-grance and scenic view” (Jung et al., 2015, p. 274). In Taiwan, forest therapy is considered as recreational activities using forest resources to improve health and well-being. The “forest therapy program” devel-oped by Taiwan forest therapy professionals consists of structured ac-tivities and interventions using various elements of forests to reduce participants’ stress levels and to promote health. The forest therapy program has various forms such as two hour forest walks or multi-day workshops. Researchers place importance on evidence-based in-vestigations to determine the efficacy of the program. Forest therapy research typically utilizes an evidence-based approach and field ex-periments to evaluate the health-related effects resulting from partici-pants’ experiences. Previous studies have demonstrated the restorative effects of forest therapy on mental health, whereby individuals’ nega-tive emotions were observed to decrease, and their posinega-tive emotions were noted to increase after immersion in forest environments (Lee et al., 2009,2011;Lee et al., 2014;Morita et al., 2007;Park et al., 2011; Takayama et al., 2014). The mental stress recovery effects were further identified in middle-aged and elderly groups, (Chen et al., 2018;Ochiai et al., 2015a;Yu et al., 2017) as well as in individuals with chronic conditions (Mao et al., 2012;Ochiai et al., 2015b;Shin et al., 2013; Song et al., 2015a). Furthermore, forest therapy has been noted to improve comfort (Lee et al., 2009,2011) and energy levels (Park et al., 2010; Yu et al., 2017). Studies have also determined a relationship between forest therapy and physical health, namely a reduced pulse rate, lower blood pressure (Lee et al., 2009;Mao et al., 2012;Ochiai et al., 2015b; Park et al., 2009, 2010; Song et al., 2015a, 2017; Tsunetsugu et al., 2007, 2013), increased parasympathetic nervous system activity, and decreased sympathetic nervous system activity (Lee et al., 2011,2014;Park et al., 2007,2008;Park et al., 2009,2010). Li and colleagues conducted a series of studies and provided consistent evidence regarding the effects of forests on the immune system; these effects were mediated through increases in the number of NK cells and their activity, as well as changes in presence of anticancer proteins (Li, 2010;Li et al., 2007,2008a;Li et al., 2008b). In addition,Song et al. (2015b)highlighted the physiological adjustment effect in the forest environment and their study found subjects with high initial blood pressure and pulse rate showed a decrease in these measures after walking in a forest environment, whereas those with low initial values showed an increase. Interestingly, this physiological adjustment effect was not observed in an urban setting and was specific to the forest environment (Song et al., 2015b). In other words, forest walking fa-cilitates an adjustment of the physiological responses close to an ap-propriate level that benefits physical health and this physiological regulation should be considered as a health benefit of forest therapy.
Forest therapy primarily focuses on stress recovery, with the out-comes of exposure to nature mostly related to induced levels of re-storation and increased positive affects (Hartig et al., 1991, 2014; McMahan and Estes, 2015). From the restorative perspective, it is suggested cognitive and attentional performance can be improved through interactions with nature (Berman et al., 2008;Kaplan, 1995; Kaplan and Kaplan, 1989).Stevenson et al. (2018)articulated cognitive performance (e.g. working memory, cognitive flexibility, attention control, visual attention process, processing speed and etc.) is sensitive to the restoration effect and improves after exposure to nature.
Empirical studies have demonstrated the benefits of being in nature on cognition, including directed attention improvement (Berman et al., 2008, 2012; Tennessen and Cimprich, 1995), attentional capacity (Berto, 2005; Berto et al., 2008; Staats et al., 2003), and memory function (Pilotti et al., 2014). Consistent with this stance, participants of forest therapy may experience higher-level executive cognitive functioning, such as enhanced creativity. Furthermore, scholars de-scribe a pathway that exposure to nature consistently resulted in a positive affect that consequently led to increased performance in creative problem-solving (Baas et al., 2008; Mikulincer and Sheffi, 2000;Pasanen et al., 2018). In other words, improvement of creativity through cognitive and attentional enhancement of being in nature (i.e. cold pathway) and increased creative performance via positive affect (i.e. hot pathway) were suggested in existing creativity literature. Both pathways (cognition to creativity and positive affect to creativity) il-lustrate time spent in nature influencing a person’s creativity. Verily, a growing amount of evidence indicates being in natural environments promotes creativity. Recently a qualitative study investigated the in-fluence of the natural environment on creativity, and it concluded nature plays a significant role in the preparation phrase (i.e. giving attention to a topic, gathering information and exploring aspects of said topic) and incubation phrase (i.e. conscious or unconscious cognitive processes enabling new ideas to emerge) of creative development (Plambech and Konijnendijk van den Bosch, 2015). Specifically, through the lens of Attention Restoration Theory (ART), nature ex-periences promote creativity by providing a break from effort-intensive preparation of a creative task and improving conscious work during the incubation period via recovery from fatigue (Plambech and Konijnendijk van den Bosch, 2015; van Rompay & Jol, 2016;Sio and Ormerod, 2015;Williams et al., 2018).
Scholars have indicated remote association is a critical part of the creative process. For example, Ghiselin (1952) analyzed the auto-biographies of poets, novelists, and mathematicians and discovered these creative people shared the following characteristic in their crea-tive process: they each had experience of synthesizing various concepts into their creation. In addition,Mednick (1962)outlined the associative theory of creative thinking, which defines creativity from the perspec-tive of remote association as the process of associating certain things for achieving specific needs or practical goals. Adhering to this theory, Mednick developed the Remote Associates Test (RAT)(Mednick, 1962, 1968). RAT has been widely used as a measure of creative thinking and insightful problem-solving in various fields owing to its advantages, such as a short testing time, a simple-to-implement procedure, limited answer choices, and an objective scoring system (Ansburg, 2000; Cerruti and Schlaug, 2009;Fodor, 1999;Mikulincer and Sheffi, 2000; Ward et al., 2008;Weinstein and Graves, 2002;Zhong et al., 2008). In an outdoor and creativity studyAtchley et al. (2012)applied RAT and observed a 50 % increase in the RAT score after 4 days of exposure to nature in a group of naive hikers. Based on the research methods em-ployed by Atchley et al. (2012); Ferraro III (2015) investigated the influence of a 6-day outdoor trip and determined the experimental group’s average score was 49 % higher than that of the control group. Their findings indicated immersion in a natural setting offers a cogni-tive advantage that implies the forest therapy workshop, in the study context, may improve creativity.
Existing literature highlights the restorative effects of forest therapy, and these benefits appear to enhance creativity. There is a growing interest in forest therapy research, and it should be noted the afore-mentioned forest therapy studies refer to a variety of interactions with nature, such as forest viewing, forest walking, or structured activities in forests, each of which depends on the context of the respective study. In the current study we conducted the investigation to gain a better un-derstanding of physical and mental health benefits, as well improve-ments in creativity resulting from participation in the 3-day workshop-based forest therapy program. Our research questions were: What are the physical and mental health benefits from the 3-day forest therapy
workshop? Does the forest therapy workshop improve creativity? What type of emotional change is associated with creativity enhancement (if any)? Following these questions, the three purposes of the study were: (1) assessing physiological and psychological (mood states) responses of the 3-day forest therapy workshop, (2) evaluating the effect of the forest therapy workshop on creativity, and (3) examining the re-lationship between changes in emotions and changes in creativity. This study extends stress recovery forest therapy research by evaluating creativity, thus providing insights into high-level cognitive functioning (e.g., creativity) improvement resulting from the 3-day forest therapy workshop.
2. Methods
2.1. Participants and the 3-day forest therapy workshop
The 3-day forest therapy workshop was implemented March 2018 in Da’an, Taiwan. We recruited research participants from the attendees of the 2018 Da’an Forest Therapy Workshop in Taiwan. Participants were recruited if they agreed to follow the experimental procedure, undergo tests throughout the experimental period, and comply with the test regulations. The 3-day forest therapy workshop involved 32 attendees in total, 24 of which agreed to participate in the study, but one parti-cipant left the workshop and only completed the pre-test. Therefore, we excluded that participant’s response from our sample, resulting in 23 valid responses. However, we initially received 23 responses for the Profile of Mood States (POMS) scale but determined one response was invalid due to its fixed order responses, resulting in 22 valid responses for the POMS scale. Further, we found missing values in the tensio-n–anxiety dimension of one survey, so the number of valid responses for this dimension was 21. Regarding the age of the participants, 6 were young adults (< 44 years; 26.1 %) and 17 were middle-aged to older adults (≥45 years; 73.9 %). The average age of participants was 52.0 ± 12.54 years old and their age ranged from 25 to 70. Eight participants were male (34.8 %).
The 2018 Da’an Forest Therapy Workshop aimed to promote the health of its attendees. During the workshop three speakers introduced the concept of forest therapy, detailed the relevant forest therapy cases, and hosted sensory experience activities that revealed the healing po-tential of forest therapy. Such therapeutic activities included forest walking; sitting and observing the forest; outdoor meditation; listening to the sound of running water; being alone; enjoying flowers, trees, and water; eating foods made from local forest ingredients; aromatherapy; and making bamboo handicrafts (seeTable 1for the schedule).
2.2. Research design
Following the pre-test and post-test experimental design of prior studies for investigating the benefits of forest therapy (Ochiai et al., 2015a,b;Yu et al., 2016;Yu et al., 2017), the present study employed a one-group pre-test and post-test design. The pre-test and post-test were conducted on the first day and the final day of the workshop, respec-tively. The same data collection process was utilized for both the pre-test and the post-pre-test. Both the pre-pre-test and the post-pre-test were conducted at approximately noon to ensure consistency in test timing and to avoid the influence of biological rhythms on study variables. All participants were informed of the research objectives and methods and were asked to sign a consent form as proof of their consent to participate in the study. This study was approved by the Research Ethics Office of Na-tional Taiwan University (NTU-REC No. 201607HS008).
2.3. Physiological and physiological measurements
Participants’ heart rates and blood pressures were measured using the electronic blood pressure monitor HEM-1000 (Omron, Japan), which has been widely used in forest therapy studies for examining the
effects of forest therapy (Lee et al., 2009;Song et al., 2013). For as-sessing participants’ mood states, we employed the Short Form of the Profile of Mood States (POMS-SF) scale (Shacham, 1983), which is most widely used in forest therapy studies for examining mood state changes (Lee et al., 2011;Park et al., 2010). This scale is used to measure the current emotional state in the following dimensions: tension–anxiety, anger–hostility, fatigue–inertia, depression–dejection, con-fusion–bewilderment, and vigor–activity. The POMS scale is scored on a 4-point Likert scale, ranging from 0 to 3 points, with 0 = never, 1 = sometimes, 2 = often, and 3 = always. The sum of points received for items in one dimension is the total score for that dimension; a high total score indicates a high level of that emotion represented in the dimen-sion. The total mood disturbance (TMD) of participants was calculated to estimate the overall level of negative emotions.
2.4. Creativity measurement
This study employed remote association as the indicator of crea-tivity based on the creacrea-tivity indicators suggested by Atchley et al. (2012)andFerraro III (2015). During a Remote Associates Test (RAT, Mednick, 1962,1968), participants were presented with three remote words in each test item and were asked to provide a common word that linked the three words. For example, in the test items “same,” “head,” and “tennis,” the participants were required to find a common word that links the three words, such as “match.” The RAT is comprised of 30 test items, each of which is worth 1 point. The final RAT score is cal-culated based on the number of correct answers. In this study we used the Chinese Word RAT (CWRAT), adapted from Mednick (1962) by Huang et al. (2012). The CWRAT consists of two tests, test-A and test-B, which have been previously demonstrated to offer favorable reliability and validity, as well as to effectively measure an individual’s remote association ability and creative potential (Huang et al., 2012). The two tests were used as the pre-test and the post-test in order to avoid a learning effect from repeating the same test form. Law requires the test to only be conducted by psychology professionals, such as counselors, medical specialists, and/or academic researchers. To meet this re-quirement, we invited a qualified psychologist to conduct the creativity tests and mark the responses. The CWRAT has 30 items in each of the two tests, with a three-word stimulus provided in each item. Partici-pants were asked to provide a term that linked the three words and they had 10 min to complete the test. The responses were marked referring
Table 1
Schedule of forest therapy in this study.
Day Time Program
Day 1 11:30－12:30 Registration/lunch 12:30－14:00 Pre-test
14:00－16:00 Introduction of forest therapy 16:00－17:00 Walking in the forest 17:00－19:00 Dinner
19:00－20:00 Counselling 20:00－ Free time and sleeping Day 2 8:00－8:50 Breakfast
9:00－10:30 Health benefits of forest therapy 11:00－12:30 Meditation and exercise in the forest 12:30－14:00 Lunch break
14:00－16:00 Forest therapy cases 16:00－18:00 hand-making bamboo cutlery 18:00－19:30 Dinner
19:30－21:00 Nature and art therapy 21:00－ Free time and sleeping Day 3 7:30－8:30 Breakfast
8:30－10:30 Aroma therapy 10:30－10:40 Break 10:40－11:15 Reflection 11:30－13:00 Lunch in the forest 13:00－14:30 Post-test 14:30－ Going home
to the standard answers; each item was worth 1 point, with 30 points obtained if correct responses were provided for each item.
2.5. Data analysis
Data was analyzed using descriptive statistics, nonparametric sta-tistics, the Wilcoxon signed-rank test, and Spearman’s rank correlation coefficient. Data are expressed in terms of mean ± standard deviation (SD). In all comparisons, a p value of < 0.05 was considered statisti-cally significant and effect size (ES, calculated by dividing the absolute Z score by the square root of the number of pairs) was reported.Cohen (1988) suggested effect sizes can be referred to as small ( = 0.2), medium ( = 0.5), or large (> = 0.8).
3. Results
Overall physiological results are summarized in theTable 2. We found no significant difference in any of the physiological measures between the pre-test and post-test.
We further analyzed physiological adjustment effects. This study found the pre-test systolic blood pressure of participants significantly negatively correlated with the difference in systolic blood pressure between their pre-test and post-test (r = −0.615, p = 0.002;Fig. 1), as did their diastolic blood pressure (r = −0.711, p < 0.001; Fig. 2). Both figures illustrated potential outliers in the scatter plots, therefore we performed sensitivity analyses which tested the adjustment effects before and after excluding outliers across SBP and DBP following the guidelines by Aguinis et al. (2013). The results showed significantly negatively correlated with the difference in systolic blood pressure between their pre-test and post-test after excluding outliers (r = −0.584, p = 0.005) and as did their diastolic blood pressure
(r = −0.670, p = 0.001) (See Fig. S1). In addition, a significant ne-gative correlation between the initial value and the degree of change in both systolic pressure and diastolic blood pressure was observed during the forest therapy workshop, which is consistent with the results of Song et al. (2015b).
For psychological responses we analyzed the valid responses and examined each dimension, obtaining the following results (seeTable 3). Four of the negative subscales of POMS, “tension-anxiety,” “anger-hostility,” “depression-dejection,” and “confusion-bewilderment,” de-creased from the pre-test to the post-test (all p < 0.05). The total mood disturbance (TMD) yielded a significant difference; conversely, the positive mood state “vigor-activity” significantly increased (p < 0.01). The effect of size of significant subscales ranged from 0.42 to 0.64. The creativity (CWRAT) measurement exhibited improvement after com-pletion the forest therapy program.
Spearman’s correlation analysis (Table 4) of the change in creativity and the change in emotions revealed the change in creativity correlated significantly and negatively with the change in confusion–bewilder-ment (rho = −0.518). This finding indicates reduced feelings of con-fusion and bewilderment associates with an enhancement in creativity. 4. Discussion
In this study, we examined the physiological responses, psycholo-gical responses, and creativity enhancement upon completing the 3-day forest therapy workshop. The results showed participants’ heart rates, systolic blood pressures, and diastolic blood pressures experienced no significant changes, indicating the 3-day forest therapy workshop did not affect participants’ recoveries from physical stress. Upon further analysis we have revealed that the physiological adjustment effect that participants with higher initial systolic blood pressure and diastolic blood pressure showed decreases after the 3-day forest therapy
Table 2
A comparison of pre-test and post-test results of physiological indicators.
Indicators Mean(SD) Z p ES
N Pre-test Post-test
HR (bpm) 23 82.35 (11.68) 82.30 (11.58) −0.879 0.380 0.18 SBP (mmHg) 23 120.17 (15.18) 122.48 (13.60) −1.142 0.254 0.24 DBP (mmHg) 23 69.78 (10.23) 71.83 (7.06) −0.017 0.986 0.0035
Abbreviations: HR heart rate; SBP systolic blood pressure; DBP diastolic blood pressure. Note: Wilcoxon signed-rank test, *p < 0.05, **p < 0.01.
Fig. 1. Post-test and pre-test differences in systolic blood pressure versus initial systolic blood pressure.
Fig. 2. Post-test and pre-test differences in diastolic blood pressure versus in-itial diastolic blood pressure.
workshop, whereas those with low initial values exhibited increases. Our finding suggests the 3-day forest therapy workshop had a physio-logical benefit by regulating participants’ systolic and diastolic blood pressures. From a research design perspective the adjustment effect may cause non-significant results in physiological responses because the decreases (typically in subjects with high initial values) and the increases (typically in subjects with low initial values) offset one an-other in statistical analysis, thereby suggesting the selection of a homogeneous sample. Previous studies have suggested blood pressure decreases after visiting forests; however, the findings of prior research are not consistent with some empirical investigations (Tsunetsugu et al., 2007;Lee et al., 2011; Horiuchi et al., 2013). Inspired by the concept of “the law of initial value” (Leites, 1936;Hord et al., 1964; Wilder, 1967),Song et al. (2015b)proposed the physiological adjust-ment effect to explain the incongruity that could explain individual differences, that is, the different initial physical value of each partici-pant.
The scores for the tension–anxiety, anger–hostility, depression–de-jection, and confusion–bewilderment dimensions in the POMS scale were significantly lower after the 3-day forest therapy workshop, whereas those for the vigor–activity dimension were significantly higher, which is consistent with the findings of previous studies of forest therapy (Park et al., 2010;Yu et al., 2017). The lack of change in the fatigue–inertia dimension is consistent with the results ofOchiai et al. (2015a,b), who enrolled older women into forest therapy activ-ities and determined no change in their POMS fatigue–inertia scores after the activities. Ochiai et al. attributed this to temporary fatigue resulting from exercise in the forest. It follows, then, this 3-day forest therapy workshop with a tight schedule and walking and exercise in the forest for participants mostly of a middle or senior age could have re-sulted in fatigue. Therefore, although the fatigue–inertia score was lower after the activities, the effect was nonsignificant. From the effect size analysis we found the 3-day forest therapy workshop to have a small effect on fatigue–inertia, a moderate effect on depression-dejec-tion, and a large effect on the rest mood states. A conclusion we draw from this study is the 3-day forest therapy workshop contributed to an improvement in participants’ mood states.
In regards to creativity, we revealed a significant difference with the post-test average score being 27.74 % higher than the pre-test average
score, which is concordant with other outdoor and creativity studies (Atchley et al., 2012;Ferraro III, 2015). Therefore, our findings indicate this 3-day forest therapy workshop improves creative thinking by 27.74 %. In addition to the increased creativity resulting from forest therapy, we observed relief of negative emotions (e.g., confusion–bewilderment) was significantly associated with enhancement of creativity. Creativity literature illustrates how the cold pathway and hot pathway contribute to creative performance. The positive affect that results from time spent in nature leads to better creativity performances (Baas et al., 2008; Mikulincer et al., 2000; Pasanen et al., 2018). However, this study could not demonstrate that positive affect (e.g., vigor–activity) mark-edly and directly improves creativity; instead, our study observed al-leviation of confusion–bewilderment correlated to enhanced creativity; so, participants performed better in creative tasks when they were calm. A similar idea was proposed by (Plambech and Konijnendijk Van Den Bosch (2015), that a calming experience and a feeling of peace are essential for people to generate new ideas and see ideas from a new perspective.
This study extends forest therapy research by investigating high-level cognitive functioning (e.g., creativity) and provides direction of how to investigate health benefits and physiological adjustment effects of forest therapy. Our study provides an approach for measuring crea-tivity in forest therapy research, as creacrea-tivity improvements upon completion of the forest therapy workshop were quantified. The re-lationship between negative emotions and creativity was identified, which contributes to the effect of exposure to nature on creativity. We recognize this study has several limitations. First, this study did not have a control group due to difficulty in repeating the same metho-dology in an urban setting, which may threaten the design’s internal validity. Ideally, extraneous factors, which potentially influence results, should be controlled in the study protocol. Further, a statistical phe-nomenon is known as regression towards the mean (RTM) occurs in a repeated measurements design and often leads to an inaccurate con-clusion that the intervention resulted in a treatment effect (Barnett, et al., 2005; Linden, 2013). RTM is a ubiquitous phenomenon in re-peated data and is a risk that may lead to a false impression of treat-ment (e.g. the forest therapy workshop) efficacy in our study. RTM’s effect can be alleviated through randomized controlled trial (RCT) with a control group design and use of analysis of covariance methods (Barnett, et al., 2005). The authors thus warn readers to cautiously evaluate research findings. We suggest a control group design and a randomized controlled trial (RCT) should be applied in a future study. Secondly, the characteristics of the sample must be considered. The participants in this study shared a special interest in forest therapy program, so we cannot assume the same effects observed in this study would be observed in different populations. Therefore, it is necessary to be cautious about applying these findings to different groups. More-over, the results may be affected by other parameters, such as subjects’ health conditions, preferences for nature, visit frequencies of forest
Table 3
A comparison of pre-test and post-test results of psychological indicators and creativity.
subscales Mean(SD) Z p ES N Pre-test Post-test POMS T-A 21a 3.10(2.79) 1.57(2.56) −2.911 0.004** 0.64 A-H 22b 2.55(1.90) 1.59(2.11) −2.550 0.011* 0.54 F-I 22 1.64(2.13) 1.41(2.38) −0.740 0.459 0.16 D-D 22 2.36(2.15) 1.36(2.70) −1.975 0.048* 0.42 C-B 22 2.86(1.39) 1.91(1.15) −2.981 0.003** 0.64 V-A 22 10.55(3.56) 12.45(3.23) −2.668 0.008** 0.57 TMD 21 1.90(10.71) −4.10(11.63) −2.880 0.004** 0.63 Creativity CWRAT 23 13.48(5.00) 17.22(6.46) −2.897 0.004** 0.60
Abbreviations: T–A, tension–anxiety; A–H, anger–hostility; F–I, fatigue–inertia;D-D, depression–dejection; C–B, confusion–bewilderment; V–A, vigor–activity; TMD, total mood disturbance (calculated by combining T–A + A–H + F–I +D-D + C–B − V–A); CWRT, Chinese Word Remote Associates Test.
NoteWilcoxon signed-rank test, *p < 0.05, **p < 0.01; (a) missing values in the tension–anxiety dimension; (b) an invalid POMS response. Table 4
Spearman (rho) correlations of the change in creativity and changes in emo-tions.
ΔA_T ΔA_H ΔF_I ΔD_D ΔC_B ΔV_A ΔTMD ΔC −.301 −.115 −.034 .093 −.518* .231 .314 Sig. .173 .609 .879 .680 .014 .302 .165
environments, and environmental conditions. Future studies could benefit from understanding and planning for the potential influence of these variables. Lastly, in order to avoid a learning effect on the im-provement of creativity performance, future study should add a practice test before pre-test to eliminate the potential bias.
In conclusion, this 3-day forest therapy workshop improved phy-sical and mental health by regulating physiological responses and im-proving recovery from psychological stress. We found the forest therapy workshop improved participants’ creative performances by 27.74 %. Moreover, creativity enhancement was associated with the alleviation of confusion–bewilderment.
Funding
This research was supported by a grant from the Ministry of Science and Technology of Taiwan [105-2628-H-002-004-MY2].
CRediT authorship contribution statement
Chia-Pin (Simon) Yu: Funding acquisition, Conceptualization, Methodology, Supervision, Writing - review & editing. Hsuan Hsieh: Investigation, Data curation, Formal analysis, Writing - original draft. Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influ-ence the work reported in this paper.
Acknowledgement
We thank the staff and instructors of the 2018 Da’an Forest Therapy Workshop for their help.
Appendix A. Supplementary data
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