研究者業績

宮崎 良文

ミヤザキ ヨシフミ  (Yoshifumi Miyazaki)

基本情報

所属
千葉大学 環境健康フィールド科学センター 特任研究員 (グランドフェロー)
学位
医学博士(東京医科歯科大学)

連絡先
ymiyazakifaculty.chiba-u.jp
研究者番号
40126256
ORCID ID
 https://orcid.org/0000-0002-3170-6810
J-GLOBAL ID
200901016833477325
researchmap会員ID
6000015656

外部リンク

論文

 267
  • Harumi Ikei, Hyunju Jo, Yoshifumi Miyazaki
    Journal of Wood Science 70(21) 1-7 2024年5月13日  査読有り責任著者
    Abstract In Japanese households, it is customary to walk barefoot on wooden floors. Previous reports on the psychological and physiological relaxing effects of feet contact with uncoated solid wood have already been published. However, there are no studies on the effects of feet contact with coated wood, which is commonly used for residential floors. This study aimed to validate the psychological and physiological relaxing effects of sole contact with oil-finished wood. In total, 27 women university students (mean age: 21.9 ± 1.9 years) participated in this study. Psychological indices such as the modified semantic differential method and the Profile of Mood States Second Edition were used. The oxyhemoglobin (oxy-Hb) concentrations in the prefrontal cortex were determined using near-infrared time-resolved spectroscopy. The sympathetic nervous activity and the parasympathetic nervous activity were measured using heart rate variability. The flat plate for tactile stimulation was oil-finished wood, and uncoated wood and marble were used for comparison. The sole of the feet of each participant touched each material for 90 s. Feet contact with oil-finished and uncoated wood had relaxing effects on psychological and physiological responses compared with marble. The relaxing effects of oil-finished wood and uncoated wood were similar. That is, they significantly increased subjective feelings of comfort and relaxation, improved mood states, and decreased oxy-Hb concentration in the left prefrontal cortex compared with marble. However, there were no statistically significant differences in terms of right prefrontal cortex and sympathetic nervous activities between oil-finished wood and marble. Oil-finished wood had a slightly weaker physiological relaxation effect than uncoated wood.
  • Tomohiro Mizumoto, Harumi Ikei, Kosuke Hagiwara, Toshio Matsubara, Fumihiro Higuchi, Masaaki Kobayashi, Takahiro Yamashina, Jun Sasaki, Norihiro Yamada, Naoko Higuchi, Kenichi Haraga, Fumiaki Kirihara, Emi Okabe, Kumi Asai, Masako Hirotsu, Chong Chen, Yoshifumi Miyazaki, Shin Nakagawa
    Journal of Affective Disorders 2024年4月  査読有り
  • Harumi Ikei, Hyunju Jo, Yoshifumi Miyazaki
    2023年12月21日  査読有り
    The Proceedings Book from the 18th International Conference Days of Applied Psychology titled "Current Challenges in Psychological Science" showcases a selection of papers meticulously curated from the presentations at the 18th International Conference “Days of Applied Psychology,” held on September 23rd & 24th, 2022, in an online format. Rooted in tradition, this annual conference has been a flagship event since 2005, organised by the Department of Psychology at the Faculty of Philosophy, University of Niš, Serbia. The conference's inception was underpinned by the vision of fostering a platform for the convergence of researchers and practitioners, facilitating discussions that bridge the chasm between scientific exploration and pragmatic applications across diverse psychological domains. Since its beginning, the conference has welcomed participants of international provenance, a trend that steadily gains momentum with each passing year. Over recent years, the conference has particularly focused on not only disseminating scientific findings from varied psychological disciplines but also nurturing dialogue among scholars with diverse cultural and professional backgrounds. This publication contains 12 reviewed original scientific papers. The authors of these articles come from 8 countries: Bosnia & Herzegovina, Bulgaria, India, Japan, Republic of North Macedonia, Romania, Serbia and Slovakia. The abstracts featuring the research results from these articles were presented at the conference as the part of the sessions: Personality and Individual Differences, Work, Organization & Mental Health, Protective Behaviours during the COVID-19 Pandemic, Psychometrics, Educational Psychology, Social Psychology, Motor Behaviour & Sports Psychology, Psychotherapy & Mental Health and two symposia: Forest Bathing Without the Forest: The Urban Nature Experience and Share Your Attitude: Mental Health Services, Asylum Seekers and Nationalism – Under the Veil of Personal and Some Other Factors. Paper Psychological Factors Involved in Criminal Recidivism explores the intricate interplay of psychological attributes contributing to repeated criminal behaviours. This topic resonates as a vital investigation within the discipline of criminal psychology, seeking to unveil the underlying mechanisms driving persistent engagement in criminal activities. Within the thematic section of Work, Organization & Mental Health, two papers make noteworthy contributions. Work-Family Conflict and Turnover Intention: The Mediation Role of Optimism shines a light on the interplay between work-family dynamics and the intention to leave a job, with optimism acting as a mediating factor. Simultaneously, the investigation into Job Demands, Job Resources and Personal Resources as Determinants of Burnout of Healthcare Workers During COVID-19 Pandemic sheds crucial insights into the occupational burnout experienced by healthcare personnel during times of crisis. The strand of Protective Behaviours during the COVID-19 Pandemic explores pivotal dimensions of public health behaviours. Sharing is (Not) Caring! Predicting Intent to Vaccinate Against COVID-19 by Emotional and Cognitive Factors investigates the intricate interplay of emotions and cognition in predicting vaccination intent, and Fear of COVID-19 and Personality Traits as Predictors of Motivation for Vaccination addresses the interplay between psychological attributes and vaccination motivations,
  • Harumi Ikei, Hyunju Jo, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 20(14) 6351-6351 2023年7月12日  査読有り
    The purpose of this study was to evaluate the physiological effects of visual stimulation by a unique Japanese low wooden table on the prefrontal cortex and autonomic nervous activities. A within-participants experiment with 26 male university students was conducted in a Japanese-style room. The visual stimuli were a low wooden table (WT) made of Japanese cypress and a low cloth-covered table (control) for an exposure time of 90 s. Near-infrared spectroscopy was used to measure the prefrontal cortex activity in the left and right prefrontal cortices as an indicator of oxyhemoglobin (oxy-Hb) concentration. Autonomic nervous activity was measured as an indicator of sympathetic (low-frequency/high-frequency component ratio, LF/HF), and parasympathetic (high-frequency components, HF) nervous activities were assessed by heart rate variability. Furthermore, the modified semantic differential method and the Profile of Mood States 2nd edition were used to measure psychological responses. Physiologically, the oxy-Hb concentration in the left prefrontal cortex and ln (LF/HF) were significantly lower during visual exposure to the WT than to the control. Psychologically, more comfortable, relaxed, and natural impressions, as well as improved mood states, were reported during visual stimulation to the WT than to the control. This study demonstrated that viewing a WT led to physiological relaxation and had a positive psychological effect on the participants.
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Frontiers in Psychology 14 2023年4月27日  査読有り
    Introduction: As modern societies are often stressful due to urbanization and artificialization, the physiological relaxing effects of natural environments or nature-derived stimuli on humans have attracted attention and scientific data are being accumulated. It is known that there is inter-individual variation in these effects. The study aim was to apply the law of initial values to investigate the physiological adjustment effect of viewing fresh roses on sympathetic nervous activity. Methods: In this crossover study, a total of 214 high school students, office workers, healthcare workers, and elderly people were analyzed. The participants viewed fresh roses in a vase for 4 min. In the control condition, participants did not view any fresh roses during the period. To offset any order effect, participants received visual stimuli in the order of fresh roses then the control (no fresh roses) or the control and then fresh roses. ln (LF/HF) of heart rate variability (HRV) obtained from a-a interval measurements using an acceleration plethysmograph and used as an index of sympathetic nervous activity. The initial value was ln (LF/HF) of HRV during the control viewing (no fresh roses), and the change value was ln(LF/HF) of HRV during visual stimulation by fresh roses minus the control viewing. Results and Discussion: The correlation between the two was assessed by determining Pearson’s correlation coefficient r, which was significantly negative. A physiological adjustment effect was observed such that participants with high initial sympathetic nervous activity showed a decrease in activity after visual stimulation with fresh roses, whereas participants with low initial activity showed an increase.
  • Hiroko Ochiai, Harumi Ikei, Hyunju Jo, Masayuki Ohishi, Yoshifumi Miyazaki
    Journal of Integrative and Complementary Medicine 2023年3月27日  査読有り
  • Hyunju Jo, Harumi Ikei, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 20(1) 565-565 2022年12月29日  査読有り責任著者
    Growing interest in the relaxation effect of nature has elicited demands for scientific verification of the various natural elements. This study investigated the physiological and psychological responses of 27 females in their 20 s to viewing a waterfall and urban images (control) presented via a large, high-resolution display for 90 s. High-frequency [HF] for parasympathetic nervous activity and the ratio of low-frequency (LF)/[LF + HF] for sympathetic nervous activity by heart rate variability and heart rate were recorded. Simultaneous changes in oxyhemoglobin concentration in the prefrontal cortex were recorded by near-infrared time-resolved spectroscopy. The modified semantic differential method and Profile of Mood States Second Edition were used to assess the psychological effects on the participants after viewing each image. The results showed that viewing the waterfall image, compared with viewing the urban image, (1) increased sympathetic nervous activity; (2) provided comfortable, relaxed, and natural impressions; (3) improved mood states. In conclusion, visual contact with a waterfall image physiologically activated sympathetic nervous activity and psychologically evoked positive moods and feelings.
  • Masashi Nakamura, Harumi Ikei, Yoshifumi Miyazaki
    Wood Science and Technology 2022年10月15日  査読有り
    Abstract Wood is an important material used in decorating human living environment. Knots are prominent features found on wood surface. Moreover, they are commonly considered as undesirable surface defects, which reduce not only the mechanical properties but also the aesthetic qualities of lumber. The effects of visual stimulation using knotty wood on psychological responses among humans have been relatively well investigated. However, only few studies have assessed physiological responses. Hence, the present study aimed to assess whether knotty wood surface can reduce not only psychological but also physiological benefits for humans. Two full-sized knotty wooden-wall images and a clear wooden-wall image were used as visual stimuli using computer graphics techniques. Twenty-eight adult Japanese female university students viewed each image for 90 s in random order. During exposure to the visual stimuli, the oxyhemoglobin concentrations in the left and right prefrontal cortex and heart rate variability were consecutively measured and utilized as indicators of central and autonomic nervous system activities, respectively. In addition, the psychological effects of knotty images were examined using the modified semantic differential method and the Profile of Mood State 2nd Edition. There was no significant difference in the effects of the three images on physiological responses. All visual stimuli more or less promoted psychological comfort and relaxation. However, compared with the clear wooden-wall image, the wooden-wall image with several knots was associated with reduced psychological benefits, and the psychological responses in viewing the wooden-wall image with few knots did not remarkably differ.
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 19(19) 12154-12154 2022年9月26日  査読有り
    The aim of the current study was to assess seasonal differences in physiological responses to walking in urban parks. In total, 51 Japanese male university students participated in this research. During each season, the participants walked for 15 min in an urban park and a city area, which was used as the control site. Heart-rate variability and heart rate were used as physiological indicators. The mean values of each indicator in a comparison between walking in an urban park and a city area were compared according to each season. In addition, to show the physiological effect of walking in an urban park, differences (between walking in an urban park and walking in a city area) were calculated. Then, differences according to each season were compared. The results showed that the participants had increased parasympathetic nervous system activity in all seasons except summer. Moreover, they had decreased sympathetic nervous system activity in spring and fall and decreased heart rate in all seasons. Compared with walking in urban parks in summer, walking in urban parks in spring, fall, and winter had a greater relaxation effect on parasympathetic and sympathetic nervous system activities; hence, the physiological effects of walking in urban parks vary based on season.
  • Hyunju Jo, Harumi Ikei, Yoshifumi Miyazaki
    Forests 13(9) 1492-1492 2022年9月15日  査読有り責任著者
    Empirically, viewing nature landscapes, including mountains, can promote relaxation. This study aimed to examine the physiological and psychological effects of visual stimulation using an autumn foliage mountain landscape image on autonomic nervous and brain activities. We included 27 female university students who viewed mountain and city (control) landscape images displayed on a large, high-resolution display for 90 seconds. As an indicator of autonomic nervous activity, heart rate variability (high frequency [HF], reflecting parasympathetic nervous activity, and low frequency/high frequency [LF/HF], reflecting sympathetic nervous activity) and heart rate were recorded. Simultaneously, as an indicator of brain activity, oxyhemoglobin concentrations in the prefrontal cortex were assessed using near-infrared time-resolved spectroscopy. Viewing the mountain landscape image significantly increased HF, indicating increased parasympathetic nervous activity. Furthermore, the visual stimulation using the mountain image induced comfortable, relaxed, and natural feelings, as well as improved mood states. In conclusion, viewing an autumn foliage mountain landscape image via large display induced physiological and psychological relaxation in women in their 20s.
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    Urban Forestry & Urban Greening 64 2021年9月  査読有り
    This study aimed to demonstrate the effects of forest-derived visual, auditory, and combined stimulation on brain activity, autonomic nervous system activity, and subjective spatial impressions. The participants included 20 Japanese female university students (age 22.1 +/- 1.8 years). Each participant viewed a gray image for 60 s with no sound (rest period), followed by an image of a forest scene with no sound (visual stimulation), a gray image with forest sounds (auditory stimulation), an image of a forest scene with forest sounds (combined stimulation), and a gray image with no sound (control) for 90 s. As indicators, near-infrared spectroscopy, heart rate variability measurement, heart rate monitoring, and modified semantic differential method were used. Compared to the control condition, combined stimulation significantly decreased oxyhemoglobin (oxy-Hb) concentrations in both prefrontal cortices and increased parasympathetic nervous activity, reflecting a relaxed state; visual and auditory stimulation significantly decreased the oxy-Hb concentration in the right prefrontal cortex; and "comfortable," "relaxed," "natural," and "realistic" feelings increased significantly for all stimulations. In conclusion, forest-derived visual, auditory, and combined stimuli induced physiologically and psychologically relaxing effects, and physiological relaxation was more pronounced under combined stimulus.
  • Rikuto Yamashita, Chong Chen, Toshio Matsubara, Kosuke Hagiwara, Masato Inamura, Kohei Aga, Masako Hirotsu, Tomoe Seki, Akiyo Takao, Erika Nakagawa, Ayumi Kobayashi, Yuko Fujii, Keiko Hirata, Harumi Ikei, Yoshifumi Miyazaki, Shin Nakagawa
    International Journal of Environmental Research and Public Health 18(10) 2021年5月  査読有り
    It has been recently suggested that contact with nature improves mood via reducing the activity of the prefrontal cortex. However, the specific regions within the prefrontal cortex that underlie this effect remain unclear. In this study, we aimed to identify the specific regions involved in the mood-improving effect of viewing images of nature using a 52-channel functional near-infrared spectroscopy (fNIRS). Specifically, we focused on the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (dlPFC), two regions associated with affective processing and control. In a randomized controlled crossover experiment, we assigned thirty young adults to view images of nature and built environments for three minutes each in a counterbalanced order. During image viewing, participants wore a fNIRS probe cap and had their oxyhemoglobin (oxy-Hb) measured. Immediately following each image viewing, participants indicated their mood in terms of comfortableness, relaxation, and vigor. Results showed that viewing images of nature significantly increased comfortableness and relaxation but not vigor compared to viewing images of built environments, with a large effect size. Meanwhile, the concentration of oxy-Hb in only the right OFC and none of the other regions significantly decreased while viewing the images of nature compared to built environments, with a medium effect size. We speculate that viewing images of nature improves mood by reducing the activity of or calming the OFC. Since the OFC is hyperactive in patients with depression and anxiety at rest, contact with nature might have therapeutic effects for them.
  • Hiromitsu Kobayashi, Harumi Ikei, Chorong Song, Takahide Kagawa, Yoshifumi Miyazaki
    Urban Forestry & Urban Greening 57 126920-126920 2021年1月  査読有り
  • Harumi Ikei, Masashi Nakamura, Yoshifumi Miyazaki
    Sustainability 12(23) 9898-9898 2020年11月26日  査読有り
    Wood is a sustainable and natural material used in interior design for living environment. Knots are prominent features on wood surfaces, and they affect a user’s building preference and impression. Data on the effects of wood knots on human physiological responses are limited. Hence, further studies should be conducted. This study examined the effects of interior wall images comprising knotty or clear wood on physiological responses. Computer graphics were used to prepare wall images of knotty or clear lumber. A gray image was set as the control. In total, 28 adult Japanese female university students were included in this study. They observed two types of wood interior wall images for 90 s. The control was also set for 90 s. The oxyhemoglobin level in the prefrontal cortex measured by near-infrared time-resolved spectroscopy (TRS) and the activities of parasympathetic and sympathetic nerves assessed using the heart rate variability (HRV) were utilized as physiological indexes. TRS sensors, which emit and receive near-infrared light, were attached to frontal pole (Fp) 1 and Fp2, based on the international 10–20 method. R-R interval was measured using HRV sensors attached based on the three-point guidance method, and frequency data were analyzed to assess high frequency (HF), which reflects parasympathetic nervous system activity, and the ratio of high and low frequencies (LF/HF), which reflects sympathetic nervous system activity. The knotty wood sedated the right prefrontal cortex activity compared with the control and enhanced parasympathetic nerve activity compared with before stimulation. Clear wood sedated the left prefrontal cortex activity compared with the control and suppressed sympathetic nerve activity compared with before stimulation. Subjective evaluations revealed that compared with gray wall images, both knotty and clear wood images significantly promoted comfort, relaxation, and natural feeling and improved overall mood states. In addition, clear wood image had a more positive subjective effect than knotty image. Wall images comprising knotty or clear wood, when used as a visual stimulus, have a physiological relaxation effect among adult women in their 20s.
  • Hyunju Jo, Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Urban Forestry and Urban Greening 55 2020年11月  査読有り責任著者
    © 2020 The Author(s) Studies on the psychological effects of nature have been increasing, but few studies have focused on individual differences in these effects. The purpose of this study was to examine the individual differences in the psychological effects of forest sounds based on Type A and Type B behavior patterns. The Kwansei Gakuin (KG) daily life questionnaire was used as an indicator for Type A and Type B behavior patterns. This study included 29 female university students (mean age, 22.3 ± 2.1 years) who were exposed to high-resolution forest and city sounds for 60 s, and they provided subjective evaluations on a modified Semantic Differential method and the Profile of Mood States questionnaire. After exposure to the forest sounds, the Type A group (n = 12) reported higher levels of feeling comfortable, relaxed, and natural, as well as lower levels of anger–hostility, than the Type B group (n = 17). The findings demonstrated that the Type A and Type B groups experienced different psychological effects from forest-derived auditory stimulation.
  • Chorong Song, Harumi Ikei, Takahide Kagawa, Yoshifumi Miyazaki
    Sustainability (Switzerland) 12(16) 2020年8月  査読有り
    © 2020 by the authors. Benefits related to health promotion by getting closer to forests have received increasing attention in modern stressful society; however, evidence-based research about how our brain activity changes when we stay in a forest environment is limited. Thus, the goal of this study was to evaluate the influence of viewing real forest landscapes on the activity in the prefrontal cortex area of young women's brains. The experiment included 29 women (age: 21.0 ± 1.4 years) and was executed in five forest and five urban areas. The participants stayed in the forest and urban areas and viewed each view for 15 min. While viewing scenery, they had the oxyhemoglobin (oxy-Hb) concentrations in the left and right areas of their prefrontal cortexes measured continuously. Viewing real forest landscapes was associated with a significantly lower oxy-Hb concentration in the right area of the prefrontal cortex than when seeing urban areas. In conclusion, viewing real forest landscapes substantially diminished oxy-Hb concentrations in the right area of the prefrontal cortex, which is linked to physiological relaxation.
  • Chorong Song, Harumi Ikei, Bum-Jin Park, Juyoung Lee, Takahide Kagawa, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 17(15) 5479-5479 2020年7月29日  査読有り
    The aim of this study was to validate the psychological advantages of viewing forest landscapes. Moreover, the associations between trait anxiety levels and psychological responses were evaluated. A total of 650 university male students (age, 21.7 ± 1.6 years) viewed a scenery in a forested area and an urban area for 15 min. Furthermore, the Profile of Mood States questionnaire and State-Trait Anxiety Inventory were employed for the assessment of the psychological responses and the level of trait anxiety, respectively, of the participants. Results showed that compared with viewing a city area, viewing forest areas increased positive mood state, such as vigor, and decreased negative mood states. Furthermore, trait anxiety level and changes in the psychological responses such as depression–dejection, fatigue, and confusion after viewing forest landscapes were significantly correlated. The participants with high anxiety levels had greater reduction in negative mood state, including confusion, than those with low anxiety levels. In conclusion, viewing forest landscapes induced psychological relaxation, which was more evident in individuals with high anxiety levels.
  • Hiroko Ochiai, Chorong Song, Hyunju Jo, Masayuki Oishi, Michiko Imai, Yoshifumi Miyazaki
    Sustainability 12(15) 5969-5969 2020年7月24日  査読有り
    The number of people addicted to gambling has increased worldwide. They often suffer from debilitating medical conditions associated with stress or depression. This study examined the physiological and psychological reactions of gambling disorder (GD) patients while listening to high-definition forest or city sounds using headphones. In total, 12 Japanese male GD patients were exposed to high-definition forest or city sound waves for 1 min via headphones. Near-infrared spectroscopy of the prefrontal cortex was used to examine oxyhemoglobin (oxy-Hb) concentrations. Heart rate and heart rate variability are indicators of autonomic nervous function. We performed subjective evaluation via the modified version of the semantic differential (SD) method with the profiles of the mood states (POMS). Experiencing forest sounds led to substantial differences as opposed to listening to city sounds: (1) oxy-Hb levels of the bilateral prefrontal cortices were lower (2) the modified SD method resulted in increased comfortable and relaxed feelings, (3) the negative POMS subscale scores were significantly lower, indicating that negative emotions diminished markedly when patients listened to forest sounds. This is the first study to show that sounds of forest relaxed individuals physiologically and psychologically to minimize GD.
  • Na Lu, Chorong Song, Takanori Kuronuma, Harumi Ikei, Yoshifumi Miyazaki, Michiko Takagaki
    Sustainability 12(12) 5058-5058 2020年6月21日  査読有り
    Population growth and increased stress caused by urbanization have led to social problems that are predicted to intensify in the future. In these conditions, the recently established ”nature therapy” has revealed that an environment rich in various plant life significantly contributes to the relief of physical and mental stress. Meanwhile, from the perspective of reduction in the energy required for transportation and the retention of plant freshness, urban horticulture, in which plant life exists harmoniously with the city, has attracted considerable attention. Interactions between humans and plants in urban horticulture are considered to contribute to the good health and wellbeing of people. Therefore, we incorporate human-centered thinking based on nature therapy into horticultural produce-centered thinking based on conventional urban horticulture. By introducing a pioneering urban horticulture plant factory as an example, we propose the possibility of sustainable urban horticulture based on nature therapy.
  • Harumi Ikei, Yoshifumi Miyazaki
    Journal of Wood Science 66(1) 2020年4月  査読有り責任著者
  • Hiromitsu Kobayashi, Chorong Song, Harumi Ikei, Bum-Jin Park, Takahide Kagawa, Yoshifumi Miyazaki
    Frontiers in Public Health 7 2019年12月12日  査読有り責任著者
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Journal of Wood Science 65(1) 2019年12月  査読有り責任著者
  • Masashi Nakamura, Harumi Ikei, Yoshifumi Miyazaki
    Journal of Wood Science 65(1) 2019年12月  査読有り責任著者
  • Hyunju Jo, Chorong Song, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 16(23) 4739-4739 2019年11月27日  査読有り責任著者
    Contact with nature has been proposed as a solution to achieve physiological relaxation and stress recovery, and a number of scientific verification outcomes have been shown. Compared with studies of the other senses, studies investigating the visual effects of nature have been at the forefront of this research field. A variety of physiological indicators adopted for use in indoor experiments have shown the benefits of viewing nature. In this systematic review, we examined current peer-reviewed articles regarding the physiological effects of visual stimulation from elements or representations of nature in an indoor setting. The articles were analyzed for their stimulation method, physiological measures applied, groups of participants, and outcomes. Thirty-seven articles presenting evidence of the physiological effects of viewing nature were selected. The majority of the studies that used display stimuli, such as photos, 3D images, virtual reality, and videos of natural landscapes, confirmed that viewing natural scenery led to more relaxed body responses than viewing the control. Studies that used real nature stimuli reported that visual contact with flowers, green plants, and wooden materials had positive effects on cerebral and autonomic nervous activities compared with the control. Accumulation of scientific evidence of the physiological relaxation associated with viewing elements of nature would be useful for preventive medicine, specifically nature therapy.
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    Urban Forestry & Urban Greening 44 126437-126437 2019年8月  査読有り責任著者
  • Hyunju Jo, Chorong Song, Harumi Ikei, Seiya Enomoto, Hiromitsu Kobayashi, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 16(15) 2649-2649 2019年7月24日  査読有り責任著者
    Exposure to natural sounds is known to induce feelings of relaxation; however, only few studies have provided scientific evidence on its physiological effects. This study examined prefrontal cortex and autonomic nervous activities in response to forest sound. A total of 29 female university students (mean age 22.3 ± 2.1 years) were exposed to high-resolution sounds of a forest or city for 60 s, using headphones. Oxyhemoglobin (oxy-Hb) concentrations in the prefrontal cortex were determined by near-infrared spectroscopy. Heart rate, the high-frequency component of heart rate variability (which reflects parasympathetic nervous activity), and the ratio of low-frequency to high-frequency (LF/HF) components (which reflects sympathetic nervous activity) were measured. Subjective evaluation was performed using the modified semantic differential method and profiles of mood states. Exposure to the forest sound resulted in the following significant differences compared with exposure to city sound: decreased oxy-Hb concentrations in the right prefrontal cortex; decreased ln(LF/HF); decreased heart rate; improved feelings described as “comfortable,’’ “relaxed,” and “natural”; and improved mood states. The findings of this study demonstrated that forest-derived auditory stimulation induced physiological and psychological relaxation effects.
  • Chorong Song, Hharumi Ikei, Takahide Kagawa, Yoshifumi Miyazaki
    Forests 10(8) 635 2019年7月  査読有り責任著者
  • Chorong Song, Harumi Ikei, Takahide Kagawa, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 16(2) 229 2019年1月  査読有り責任著者
  • 池井晴美, 宋チョロン, 宮崎良文
    木材工業 73(12) 542-549 2018年12月  査読有り
  • Chorong Song, Harumi Ikei, Bum-Jin Park, Juyoung Lee, Takahide Kagawa, Yoshifumi Miyazaki
    15(12) 2804 2018年12月  査読有り責任著者
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 15(10) 2135 2018年9月  査読有り責任著者
  • Hiromitsu Kobayashi, Chorong Song, Harumi Ikei, Bum-Jin Park, Juyoung Lee, Takahide Kagawa, Yoshifumi Miyazaki
    Frontiers in Public Health-Environmental Health 2018年9月  査読有り責任著者
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 15(2) 213 2018年2月1日  査読有り責任著者
    This study was aimed to clarify the physiological effects of visual stimulation using forest imagery on activity of the brain and autonomic nervous system. Seventeen female university students (mean age, 21.1 ± 1.0 years) participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb) concentrations were measured in the left and right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) was used as an indicator of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflected parasympathetic nervous activity, and the ratio of low-frequency (LF) and high-frequency components (LF/HF), which reflected sympathetic nervous activity, were measured. Forest and city (control) images were used as visual stimuli using a large plasma display window. After sitting at rest viewing a gray background for 60 s, participants viewed two images for 90 s. During rest and visual stimulation, HRV and oxy-Hb concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of feelings was performed using a modified semantic differential (SD) method. The results showed that visual stimulation with forest imagery induced (1) a significant decrease in oxy-Hb concentrations in the right prefrontal cortex and (2) a significant increase in perceptions of feeling “comfortable,” “relaxed,” and “natural.”
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Journal of Wood Science 64(3) 226-236 2018年1月  査読有り責任著者
    ©2018, This study aimed to clarify the physiological effects of touching hinoki cypress (hereinafter called “hinoki”) (Chamaecyparis<br /> obtusa) wood with the palm of the right hand on brain activity and autonomic nervous activity. Twenty-two female<br /> university students (mean age 21.1 ± 0.2 years) participated in the study. As an indicator of brain activity, oxyhemoglobin<br /> (oxy-Hb) concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy.<br /> Heart rate variability (HRV) was used as an indicator of autonomic nervous activity. The high-frequency (HF) component of<br /> HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflected sympathetic<br /> nervous activity, were measured. Plate (300 × 300 mm) of uncoated hinoki was used as tactile stimulation. Marble was used<br /> as a control material. After sitting at rest with their eyes closed, the participants touched the materials for 90 s with their<br /> eyes still closed. The results showed that tactile stimulation with hinoki significantly decreased oxy-Hb concentration in the<br /> left prefrontal cortex and increased ln(HF) reflected parasympathetic nervous activity compared with marble. In conclusion,<br /> our study showed that touching hinoki wood with the palm calms prefrontal cortex activity and increases parasympathetic<br /> nervous activity, thereby inducing physiological relaxation.
  • Chorong Song, Miho Igarashi, Harumi Ikei, Yoshifumi Miyazaki
    Complementary Therapies in Medicine 35 78-84 2017年12月  査読有り
    Objectives: The present study aimed to clarify the effects of viewing fresh roses on prefrontal cortex activity, autonomic nervous activity and subjective assessments of psychological relaxation. Design: A crossover design, in which each experimental group crosses over from one treatment to another, was used. Setting and interventions: A total of 15 female university students (mean age 21.7 +/- 1.1 years) viewed fresh roses for 3 min; the control consisted of no experimental stimulus. Main outcome measures: Physiological effects on prefrontal cortex activity were determined by near-infrared time-resolved spectroscopy, which was assessed by measuring oxyhemoglobin (oxy-Hb) concentration in the left and right prefrontal cortex; effects on autonomic nervous activity were assessed by measuring heart rate variability (HRV) and heart rate. Modified semantic differential method and Profile of Mood States were used to determine subjective evaluations. Results: Viewing roses induced: 1) a significant decrease in oxy-Hb concentrations in the right prefrontal cortex; 2) a marginally significant decrease in ln[LF/(LF + HF)] of HRV, which is associated with sympathetic nervous activity; 3) a significant increase in perceptions of feeling 'comfortable,' relaxed,' and 'natural;' and 4) a significant improvement in mood state. Conclusions: These findings indicate that visual stimulation with roses induces physiological and psychological relaxation.
  • Yasuo Ohe, Harrumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Tourism Management 62 322-334 2017年10月  査読有り
    Considering the increasing demand for rural areas to play a role in easing stress mainly experienced by urban dwellers, we investigated from a multidisciplinary collaborative approach, i.e., physiological, psychological, and rural business management perspectives, the relaxation effects of forest-therapy tourism, an emerging type of rural tourism, on a group of urban office workers. Also investigated were conditions necessary for a sustainable rural business in Chizu, western Japan. First, the results verified physiological and psychological relaxation effects, which lasted from three to five days after forest therapy, The lasting physiological and psychological effects among those with systolic blood pressure &gt;= 120 mmHg, however, were weaker than in the entire sample. Second, due to the ageing and depopulation of the local community, increasing the number of households that provided home stay services was difficult. In summary, it is necessary to fully integrate scientific evidence to support a viable new rural tourism business. (C) 2017 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    Urban Forestry & Urban Greening 27 246-252 2017年10月  査読有り責任著者
    We examined the sustained effects of a forest therapy program on the blood pressure of office workers. Twenty-six office workers (mean age +/- standard deviation, 35.7 +/- 11.1 years) participated in a 1-day forest therapy program. Systolic and diastolic blood pressure and pulse rate were used as measurement indices. The evaluations were performed three times before breakfast, lunch, and dinner 3 days before, during, and 3 and 5 days after the forest therapy program. Systolic and diastolic blood pressure significantly decreased during the forest therapy program relative to the value from 3 days before the program, and this decrease was maintained 3 and 5 days after the forest therapy program. There were no significant differences in pulse rate. We then specifically focused on nine participants whose systolic blood pressure was above 120 mmHg. For the measurement before dinner, the systolic blood pressure significantly decreased (from 133.8 to 116.6 mmHg) during the forest therapy program, and this decrease was maintained at 3 and 5 days after the program (126.4 and 124.0 mmHg, respectively). A significant decrease in diastolic blood pressure (from 88.6 to 77.1 mmHg) was observed during the forest therapy program. In conclusion, systolic and diastolic blood pressure decreased during the forest therapy program and these decreases were maintained for 5 days.
  • Hiroko Ochiai, Chorong Song, Harumi Ikei, Michiko Imai, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 14(9) 1017 2017年9月  査読有り責任著者
    Nature therapy has been demonstrated to induce physiological relaxation. The psychophysiological effects of nature therapy (stimulation with bonsai trees) on adult male patients with spinal cord injury (SCI) were examined. Oxyhemoglobin concentration changes in the prefrontal cortex were measured using near-infrared spectroscopy, and heart rate variability was analyzed. Psychological responses were evaluated using the modified semantic differential method and Profile of Mood States (POMS) subscale scores. Visual stimulation of adult male patients with SCI elicited significantly decreased left prefrontal cortex activity, increased parasympathetic nervous activity, decreased sympathetic nervous activity, increased positive feelings, and resulted in lower negative POMS subscale scores. Nature therapy can lead to a state of physiological and psychological relaxation in patients with SCI.
  • Sin-Ae Park, Chorong Song, Yun-Ah Oh, Yoshifumi Miyazaki, Ki-Cheol Son
    International Journal of Environmental Research and Public Health 14(9) 1087 2017年9月  査読有り
    The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2-3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants.
  • Hiromitsu Kobayashi, Chorong Song, Harumi Ikei, Bum-Jin Park, Juyoung Lee, Takahide Kagawa, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 14(8) 931 2017年8月  査読有り
    The purpose of this study was to evaluate the effect of a forest environment on salivary cortisol concentration, particularly on the characteristics of its distribution. The participants were 348 young male subjects. The experimental sites were 34 forests and 34 urban areas across Japan. The subjects viewed the landscape (forest or urban environment) for a period of 15 min while sitting in a chair. Saliva was sampled from the participants at the end of this 15-min period and then analyzed for cortisol concentration. Differences in the skewness and kurtosis of the distributions between the two environments were tested by performing a permutation test. The cortisol concentrations exhibited larger skewness (0.76) and kurtosis (3.23) in a forest environment than in an urban environment (skewness = 0.49; kurtosis = 2.47), and these differences were statistically significant. The cortisol distribution exhibited a more peaked and longer right-tailed curve in a forest environment than in an urban environment.
  • Hiromitsu Kobayashi, Chorong Song, Harumi Ikei, Bum-Jin Park, Takahide Kagawa, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 14(9) 987 2017年8月  査読有り
    ©2017, Salivary cortisol and secretory immunoglobulin A (S-IgA) are important biomarkers<br /> for environmental and public health research. The present study investigated the diurnal<br /> variations of these salivary biomarkers, with a focus on the change of distribution characteristics<br /> (i.e., skewness and kurtosis) of the concentrations. The participants in this study were 113 healthy<br /> young males. Salivary samples were collected in the morning (6:30–7:30 a.m.) and afternoon<br /> (1:00–4:00 p.m.). The skewness and kurtosis of salivary cortisol concentrations in afternoon<br /> samples (skewness = 1.06, kurtosis = 4.78) were significantly higher than those in morning samples<br /> (skewness = 0.49, kurtosis = 2.80). The differences in skewness and kurtosis of S-IgA concentrations<br /> were non-significant; however, the standard deviation and interquartile ranges for afternoon S-IgA<br /> concentrations were significantly smaller than those for morning S-IgA concentrations. Logarithmic<br /> transformation improved the distribution of afternoon cortisol values, making it an almost normal<br /> distribution, but the transformation showed no improvement in the distribution of morning cortisol or<br /> S-IgA values. The present study explored diurnal changes in the distribution characteristics of salivary<br /> cortisol and S-IgA. Consideration of a possible diurnal change in the distribution characteristics is<br /> needed when we compare the difference in these salivary biomarkers between different times of day.
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 14(7) 773 2017年7月  査読有り
    This study examined the physiological effects of touching wood with various coating with the palm of the hand on brain activity and autonomic nervous activity. Participants were 18 female university students (mean age, 21.7 +/- 1.6 years). As an indicator of brain activity, oxyhemoglobin concentrations were measured in the left and right prefrontal cortices using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) and heart rate were used as indicators of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflects parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflects sympathetic nervous activity, were measured. Plates of uncoated, oil-finished, vitreous-finished, urethane-finished, and mirror-finished white oak wood were used as tactile stimuli. After sitting at rest with their eyes closed for 60 s, participants touched the stimuli with their palm for 90 s each. The results indicated that tactile stimulation with uncoated wood calmed prefrontal cortex activity (vs. urethane finish and mirror finish), increased parasympathetic nervous activity (vs. vitreous finish, urethane finish, and mirror finish), and decreased heart rate (vs. mirror finish), demonstrating a physiological relaxation effect. Further, tactile stimulation with oil-and vitreous-finished wood calmed left prefrontal cortex activity and decreased heart rate relative to mirror-finished wood.
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 14(7) 801 2017年7月  査読有り
    This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7 +/- 1.6 years) participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb) concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) was used as an indicator of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1) decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2) increased ln(HF)-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Journal of Wood Science 63(1) 1-23 2017年2月  査読有り
    It is empirically known that wood can cause a comfort enhancement effect in humans. On the other hand, not enough scientific knowledge based on evidence-based research is available on this subject. However, data using physiological indices have increasingly accumulated in recent years. This review provides an overview of the current situation for peer-reviewed reports related to the physiological effects of wood. We reviewed reports that elucidated the effects of wood-derived stimulations on the olfactory, visual, auditory, and tactile sensations using physiological indices such as brain activity (e.g., near-infrared spectroscopy) and autonomic nervous activity (e.g., heart rate variability and blood pressure). It became clear that many studies were limited by (1) a small number of participants, mostly aged in their 20s; (2) use of only a single stimulus (e.g., only olfactory or only visual), or (3) an incomplete experimental design. In addition, this review examined the field of forest therapy, for which there is abundant research. Further study is needed to elucidate the physiological effects of wood on humans.
  • Chorong Song, Harumi Ikei, Maiko Kobayashi, Takashi Miura, Qing Li, Takahide Kagawa, Shigeyoshi Kumeda, Michiko Imai, Yoshifumi Miyazaki
    Urban Forestry & Urban Greening 21 247-252 2017年1月  査読有り
    With increasing attention on the health benefits of a forest environment, evidence-based research is required. This study aims to provide scientific evidence concerning the physiological and psychological effects of exposure to the forest environment on middle-aged hypertensive men. Twenty participants (58.0 +/- 10.6 years) were instructed to sit on chairs and view the landscapes of forest and urban (as control) environments for 10 min. Heart rate variability (HRV) and heart rate were used to quantify physiological responses. The modified semantic differential method was used to determine psychological responses. Consequently, the high-frequency component of HRV, a marker of parasympathetic nervous activity that is enhanced in relaxing situations, was significantly higher and heart rate was significantly lower in participants viewing the forest area than in those viewing the urban area. The questionnaire results indicated that viewing the forest environment increased "comfortable," "relaxed," and "natural" feelings than viewing the urban environment. In conclusion, viewing forest landscape produces physiological and psychological relaxation effects on middle-aged hypertensive men. (C) 2016 The Authors. Published by Elsevier GmbH.
  • Harumi Ikei, Chorong Song, Yoshifumi Miyazaki
    Journal of Wood Science 62(6) 568-572 2016年12月  査読有り
  • Sin-Ae Park, Chorong Song, Ji-Young Choi, Ki-Cheol Son, Yoshifumi Miyazaki
    HortScience 51(10) 1308-1312 2016年10月  査読有り
    The study's objective was to investigate the effects of foliage plants on prefrontal cortex activity and subjective assessments of psychological relaxation. In a crossover experimental design, 24 male university students in their 20s observed a container with and without foliage plants for 3 minutes while oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex was continuously measured with a portable near-infrared (NIR) spectroscopy device. Afterward, subjective evaluations of emotions were obtained via two self-report questionnaires: a modified semantic differential (SD) method and the Profile of Mood State questionnaire (POMS). Oxy-Hb concentration in the right prefrontal cortex was significantly lower in subjects who viewed the foliage plants than in those who did not, indicating a physiologically relaxed state. The subjects also reported in the SD method significantly more positive emotions (e.g., comfortable, natural, and relaxed) associated with viewing the foliage plants. In the POMS, a significant positive effect on psychological relaxation when subjects viewed the foliage plants was shown. Thus, we conclude that foliage plants have both physiological and psychological relaxation effects in males even after only short exposure.
  • Chorong Song, Harumi Ikei, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 13(8) 2016年8月  査読有り
    Humans have evolved into what they are today after the passage of 6-7 million years. If we define the beginning of urbanization as the rise of the industrial revolution, less than 0.01% of our species' history has been spent in modern surroundings. Humans have spent over 99.99% of their time living in the natural environment. The gap between the natural setting, for which our physiological functions are adapted, and the highly urbanized and artificial setting that we inhabit is a contributing cause of the "stress state" in modern people. In recent years, scientific evidence supporting the physiological effects of relaxation caused by natural stimuli has accumulated. This review aimed to objectively demonstrate the physiological effects of nature therapy. We have reviewed research in Japan related to the following: (1) the physiological effects of nature therapy, including those of forests, urban green space, plants, and wooden material and (2) the analyses of individual differences that arise therein. The search was conducted in the PubMed database using various keywords. We applied our inclusion/exclusion criteria and reviewed 52 articles. Scientific data assessing physiological indicators, such as brain activity, autonomic nervous activity, endocrine activity, and immune activity, are accumulating from field and laboratory experiments. We believe that nature therapy will play an increasingly important role in preventive medicine in the future.
  • Hiroko Ochiai, Harumi Ikei, Chorong Song, Maiko Kobayashi, Takashi Miura, Takahide Kagawa, Qing Li, Shigeyoshi Kumeda, Michiko Imai, Yoshifumi Miyazaki
    International Journal of Environmental Research and Public Health 12(12) 15222-15232 2015年12月  査読有り
    The natural environment is increasingly recognized as an effective counter to urban stress, and Forest Therapy has recently attracted attention as a relaxation and stress management activity with demonstrated clinical efficacy. The present study assessed the physiological and psychological effects of a forest therapy program on middle-aged females. Seventeen Japanese females (62.2 +/- 9.4 years; mean +/- standard deviation) participated in this experiment. Pulse rate, salivary cortisol level, and psychological indices were measured on the day before forest therapy and on the forest therapy day. Pulse rate and salivary cortisol were significantly lower than baseline following forest therapy, indicating that subjects were in a physiologically relaxed state. Subjects reported feeling significantly more comfortable, relaxed, and natural according to the semantic differential (SD) method. The Profile of Mood State (POMS) negative mood subscale score for tension-anxiety was significantly lower, while that for vigor was significantly higher following forest therapy. Our study revealed that forest therapy elicited a significant (1) decrease in pulse rate, (2) decrease in salivary cortisol levels, (3) increase in positive feelings, and (4) decrease in negative feelings. In conclusion, there are substantial physiological and psychological benefits of forest therapy on middle-aged females.

MISC

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主要な書籍等出版物

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講演・口頭発表等

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社会貢献活動

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