Introduction: It is still unclear which green nature aspects can counteract psychosocial stress: the green color or rather the environmental content (=nature). Since stress is often stimulating excess/unhealthy food intake, we hypothesize that green nature also buffers stress-induced eating. This study analyzed the effects of green/nature pictures on restorativeness, stress reactivity/response and stress eating in the lab.
Methods: Before (5min) and after (8min) the Trier Social Stress Test, 81 participants (82% women, 19-30y) saw one of the four slideshows with nature or urban environments in green or black-white shades. Group differences were tested on Perceived Restorativeness Scale, five repeated measures of heart rate variability (HRV), salivary cortisol and mood, food wanting and snack buffet consumption.
Green Nature Pictures Download
Download File 🔥 https://urlca.com/2y2QmQ 🔥
Results: The four groups did not differ in background and baseline values. Reported restorative power was higher in the nature pictures than urban pictures with an even better attentional/happiness restoration capacity for green versus black-white nature, while green urban pictures might induce more stress feelings than black-white urban pictures. The stress time patterns confirmed successful stress induction. Most consistent during stress induction was a higher happiness recovery in the green nature group. Nature overall was somewhat beneficial compared to urban pictures by lower HRV and negative emotions reactivity, although this might be due to unfavorable effects of green urban pictures. In food intake or wanting, no differences existed.
Conclusion: Nature pictures were estimated higher in restorative power and green nature pictures had a positive effect on happiness recovery. Thus for prevention, the environmental content (=nature) as such seems important while just a green color seemed not enough. Future research should examine the effect of green nature in realistic indoor settings and consider influence on fruit/vegetable intake instead of solely snacks.
Since the late 20th century, the restorative effect of nature has been gradually gaining attention in the fields of environmental psychology and public health [5,6,7,8,9,10,11,12,13,14,15]. Environmental psychologists have discussed aesthetic and affective responses to the outdoor environment and the preference for natural scenery over urban landscapes, which lack natural elements [6,7,8]. In 1984, Ulrich reported that surgical patients who were assigned to rooms with windows overlooking natural scenery had shorter hospital stays and experienced fewer negative health outcomes than patients in rooms with windows facing the brick wall of a building [9].
In particular, indoor experiments, where it is possible to control the stimuli and physical environment, entail more specific and diverse methodological approaches than those used in field experiments. Of the five senses, the effectiveness of sight [33,34,35,39,40,41,42,43,44,45,46,47,48,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74], smell [36,37,38,52,53,75] and touch [49,50,51] have been discussed. The rapid development of physiological indicators has enabled evaluation of body responses such as cerebral activity (functional magnetic resonance imaging [fMRI], near-infrared spectroscopy [NIRS] and electroencephalography [EEG]), autonomic nervous activity (heart rate variability [HRV], heart rate, pulse rate and blood pressure) and endocrine activity (salivary cortisol concentration). Such data could be helpful in understanding the mechanisms underlying the physiological responses emerging from contact with nature; furthermore, the data would be useful for understanding the different effects shown by field [19,20,21,22,23,24,25,26,27,28,29,30,31,32] and indoor experiments [33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75]. In particular, compared with studies that examine the effects of the other senses, studies on the visual effects of nature are at the forefront of research. Researchers have accumulated data in this field since 1981 [6].
Another study investigated the physiological relaxation effect related to the individual preference of nature scenes [62]. Twelve male adults each viewed their individual preferred video of a sea or forest, and their physiological changes, as shown by HRV and heart rate, were recorded. The participants were divided into two groups of six on the basis of their preference for sea or forest scenery, and each physiological change indicator was compared among the groups. The heart rate while viewing the sea video was higher than that while viewing forest video. In the same year, one study examined physiological relaxation effects to determine if forest locations and vegetation density affect human attention and relaxation state [71]. One hundred and eighty university students were recruited in the study, and the participants were placed in groups of six (n = 30) that participated in a visual stimulation experiment. Pictures of three locations representing a forest interior (featuring surrounding trees and vegetation), a forest edge (featuring the visibility of the overlapping patches) and a forest exterior (featuring where the patch can be seen from far away) as well as three pictures of vegetation with different densities (high, medium and low) were collected. Six types of visual stimulation slides were eventually prepared. The participants watched the slideshow, and their electroencephalographic alpha frequency, which is associated with a state and alert relaxation, was measured. The results showed that the forest interior group had higher alpha values than those of the forest edge group, which suggested that the interior group was less relaxed than the edge group.
The technique of fMRI provides an opportunity to further explore the psychophysiological benefits of viewing natural environments. This novel approach enables direct examination of regional brain activity while viewing landscapes. Tang et al. compared the restorative value of four types of landscape environments (urban, mountain, forest and water) by using fMRI to investigate regional brain activity [60]. The study recruited 39 adults between the age of 20 and 30 years, and data from 31 participants (14 males and 17 females) were used after excluding for movement artifacts. The nature landscape included images from three types of common natural setting: mountains, forests and water. Urban landscapes were retrieved from an online gallery of photographs. In total, 12 photographs, three from each of the four categories, with similar color, lightness and layout, were used in the experiment. Compared with the mountain and water landscapes, urban images increased visual and attentional focus, which resulted in activation of the cuneus. This finding indicates that viewing mountain and water landscapes after urban landscapes may reduce activation in the visual cortex and increase activation in the rest of the attention system. Compared with urban landscapes, water landscapes were associated with increased neural activation in the attention area of the brain, which suggested that viewing water landscapes may stimulate the rest of the attention system. Interestingly, a lack of significant difference in brain activities between viewing urban and forest landscapes suggests a smaller effect on attention restoration than viewing the mountain and water landscapes. Overall, different landscapes affected regional brain activity differently; most notably, the visual and attention areas of the brain responded differently to images of urban and natural environments.
Similarly, in another study during the same year, fMRI was used to evaluate the brain activity of 30 college students with rural (13.5 5.7 years) and urban (13.8 4.4 years) life experiences [66]. Rural scenes included forests, gardens, parks, and hills, whereas urban scenes included apartments, buildings, electrical cables, and factories. Different brain areas were activated while viewing the rural and urban scenes. The superior parietal gyrus, anterior cingulate gyrus, postcentral gyrus, globus pallidus, putamen, and caudate nucleus head were mainly involved while viewing the rural scenes. In contrast, the hippocampus, parahippocampal gyrus, amygdala, and lingual gyrus were primarily involved while viewing the urban scenes. These findings demonstrated an improved characterization of neural activation, indicating that a nature-oriented lifestyle is inherently preferred.
Researchers often use the autonomic nervous system, which is vital in homeostasis and normal and stress-responsive physiology, to understand the physiological effects of nature. In 2003, a research reported heart rate response to natural and urban environments [67]. In this study, 28 female students watched a nature video depicting a waterside and an urban video depicting pedestrian streets. Consequently, the heart rate of the participants significantly decreased after viewing the nature video. In 2012, Gladwell et al. also explored autonomic nervous system control during the viewing of nature and built scenes. They measured heart rate, HRV and blood pressure [69]. Slides of nature and urban scenes were projected onto a screen (1.8 m 1.8 m) while the participants lay in a semisupine position. Standard deviation of RR intervals (SDRR), reflecting overall HRV, and parasympathetic nervous activity increased significantly during the viewing of nature images relative to those during viewing built environment scenes, which suggested increases in vagal activity. This finding suggests that the simple act of viewing nature may induce changes in autonomic control.
The following year, Brown et al. examined the effects of viewing nature scenes on the recovery of autonomic activity after the introduction of a stressor [70]. Heart rate, HRV and systolic and diastolic blood pressure were used as markers of autonomic function change, and physiological data from 23 adults were collected. The study involved showing the participants 20 photographs of nature and built scenes in the same order for 10 min (each photograph for 30 s) in a Microsoft PowerPoint slideshow. Before seeing the photographs, the participants performed a forward digit span test with an accompanying social-evaluative threat to elicit cardiovascular stress. SDRR was significantly greater in viewing nature scenes than built scenes. The finding shows that viewing images of nature improved the recovery process following a stressful event. ff782bc1db
download accident report abu dhabi