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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.

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.

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 ≥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.

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.

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.

The impact on the Profile of Mood States (POMS) of both walking in forest environments and viewing forest landscapes has already been demonstrated in previous research conducted by the authors of this paper. In both walking and viewing, decreases in tension-anxiety (T–A), depression-dejection (D), anger-hostility (A–H), fatigue (F), and confusion (C) were observed and an increase in vigor (V) was observed in forest environments when compared to urban environments. Walking and viewing exhibited similar tendencies, however the responses were quantitatively different. This study re-analyzes the POMS scores of 57 young Japanese women with specific reference to the differences between walking in and viewing forest environments. First, a comparison was made of POMS scores after walking and after viewing. F and C scores were found to be smaller after walking than after viewing, while the V score was larger after walking than after viewing. No significant differences were found in T–A, D, and A–H scores after either walking or viewing. The POMS scores in urban environment also exhibited the identical results. These results suggest that the act of walking has the psychological effect of increasing vigor and reducing some negative emotions, such as fatigue and confusion, regardless of environment. Second, to separate the walking effect from the environmental effect, the difference in forest and urban environment POMS scores was determined for each subject, and comparisons were then made between walking and viewing. The results reveal a significantly larger V score when walking than when viewing. Walking and viewing did not exhibit significant differences in other POMS scores. These results suggest that vigor is more enhanced by walking in forest environments than when viewing forest landscapes. This study, therefore, revealed the specific effects of walking in forest environments.

Background: In recent years, the physiological relaxation effects of natural environments have been widely exploited, and although individual differences in the effects of forest therapy are known, assessment methods have not been clearly established. This study used a classification based on Type A and Type B behavior patterns to explain individual differences in physiological responses to forest environments. Methods: We performed physiological experiments in 44 forest and urban (controls) areas. In total, 485 male university students (age, 21.8 ± 1.6 years) participated in the study. The subjects were asked to visit forest or urban environments randomly and observe each landscape for 15 min. The subjects’ pulse rates and blood pressures were tested to evaluate their physiological responses. The Kwansei Gakuin daily life questionnaire was used to identify Type A and Type B behavior patterns in subjects. Results: The pulse rate was significantly lower in the Type B group after exposure to forest areas than after exposure to urban areas, whereas no significant difference was observed in the Type A group. In addition, the pulse rate was significantly lower in the low scoring subjects in the Type B group, which was consistent with changes in their diastolic blood pressure. Conclusions: These results suggest that individual differences in pulse rate and blood pressure in response to forest environments can be explained by Type A and Type B behavior patterns.

The aim of this study was to investigate the physiological effects on brain activity and autonomic nervous activity of forest-related visual, olfactory, and combined visual and olfactory stimuli. Twenty-one female Japanese university students (age, 21.1 ± 1.0 years) participated. In a soundproofed chamber with an artificial climate, each participant was presented for 90 s with the following conditions: an image of a forest landscape of Hinoki cypress trees with no odor (visual stimulus), a gray image with Hinoki cypress leaf essential oil (olfactory stimulus), an image of a forest landscape of Hinoki cypress trees with Hinoki cypress leaf essential oil (combined stimulus), and a gray image with no odor (control). 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 and heart rate were used as indicators of autonomic nervous activity. The high-frequency component of heart rate variability, which reflects parasympathetic nervous activity, and the low-frequency/high-frequency ratio, which reflects sympathetic nervous activity, were evaluated. The following results were obtained in comparison with the control conditions: (1) the combined stimuli resulted in significantly decreased oxyhemoglobin concentrations in the left and right prefrontal cortices; (2) the olfactory stimulus resulted in significantly decreased oxyhemoglobin concentration in the right prefrontal cortex; and (3) the visual stimulus resulted in significantly decreased sympathetic nervous activity related to arousal or situations of stress. Results of a questionnaire indicated that these forest-related stimuli significantly increased the participants’ feelings of “comfortable” and “relaxed,” with the visual and combined stimuli significantly increasing feelings related to the terms “natural” and “realistic.” In conclusion, forest-related visual, olfactory, and combined visual and olfactory stimuli induced physiological and psychological relaxation effects, and the combined visual and olfactory stimuli exhibited an additive effect.