How nature nurtures: Amygdala activity decreases as the result of a one-hour walk in nature

Neural Correlates of Early-Life Urbanization and Their Spatial Relationships with Gene Expression, Neurotransmitter, and Behavioral Domain Atlases

Previous neuroimaging research has established associations between urban exposure during early life and alterations in brain function and structure. However, the molecular mechanisms and behavioral relevance of these associations remain largely unknown. Here, we aimed to address this question using a combined analysis of multimodal data. Initially, we calculated amplitude of low-frequency fluctuations (ALFF) and gray matter volume (GMV) using resting-state functional and structural MRI to investigate their associations with early-life urbanization in a large sample of 511 healthy young adults. Then, we examined the spatial relationships of the identified neural correlates of early-life urbanization with gene expression, neurotransmitter, and behavioral domain atlases. Results showed that higher early-life urbanization scores were correlated with increased ALFF of the right fusiform gyrus and decreased GMV of the left dorsal medial prefrontal cortex and left precuneus. Remarkably, the identified neural correlates of early-life urbanization were spatially correlated with expression of gene categories primarily involving immune system process, signal transduction, and cellular metabolic process. Concurrently, there were significant associations between the neural correlates and specific neurotransmitter systems including dopamine, acetylcholine, and serotonin. Finally, we found that the ALFF correlates were associated with behavioral terms including "perception," "sensory," "cognitive control," and "reasoning." Apart from expanding existing knowledge of early-life urban environmental risk for mental disorders and health in general, our findings may contribute to an emerging framework for integrating social science, neuroscience, genetics, and public policy to respond to the major health challenge of world urbanization.

Dimethyl fumarate ameliorates chronic stress-induced anxiety-like behaviors by decreasing neuroinflammation and neuronal activity in the amygdala

BACKGROUND

Chronic stress-induced neuroinflammation plays a pivotal role in the development and exacerbation of mental disorders, such as anxiety and depression. Dimethyl Fumarate (DMF), an effective therapeutic agent approved for the treatment of multiple sclerosis, has been widely reported to display anti-inflammatory and anti-oxidative effects. However, the impact of DMF on chronic stress-induced anxiety disorders and the exact underlying mechanisms remain largely unknown.

METHODS

We established a mouse model of chronic social defeat stress (CSDS). DMF was administered orally 1 h before daily stress session for 10 days in CSDS + DMF group. qRT-PCR and western blotting were used to analyze mRNA and protein expression of NLRP3, Caspase-1 and IL-1β. Immunofluorescence staining was carried out to detect the expression of Iba 1 and c-fos positive cells as well as morphological change of Iba 1+ microglia. Whole-cell patch-clamp recording was applied to evaluate synaptic transmission and intrinsic excitability of neurons.

RESULTS

DMF treatment significantly alleviated CSDS-induced anxiety-like behaviors in mice. Mechanistically, DMF treatment prevented CSDS-induced neuroinflammation by inhibiting the activation of microglia and NLRP3/Caspase-1/IL-1β signaling pathway in basolateral amygdala (BLA), a brain region important for emotional processing. Furthermore, DMF treatment effectively reversed the CSDS-caused disruption of excitatory and inhibitory synaptic transmission balance, as well as the increased intrinsic excitability of BLA neurons.

CONCLUSIONS

Our findings provide new evidence that DMF may exert anxiolytic effect by preventing CSDS-induced activation of NLRP3/Caspase-1/IL-1β signaling pathway and alleviating hyperactivity of BLA neurons.

Can a nature walk change your brain? Investigating hippocampal brain plasticity after one hour in a forest

In cities, the incidence of mental disorders is higher, while visits to nature have been reported to benefit mental health and brain function. However, there is a lack of knowledge about how exposure to natural and urban environments affects brain structure. To explore the causal relationship between exposure to these environments and the hippocampal formation, 60 participants were sent on a one hour walk in either a natural (forest) or an urban environment (busy street), and high-resolution hippocampal imaging was performed before and after the walks. We found that the participants who walked in the forest had an increase in subiculum volume, a hippocampal subfield involved in stress response inhibition, while no change was observed after the urban walk. However, this result did not withstand Bonferroni correction for multiple comparisons. Furthermore, the increase in subiculum volume after the forest walk was associated with a decrease in self-reported rumination. These results indicate that visits to nature can lead to observable alterations in brain structure, with potential benefits for mental health and implications for public health and urban planning policies.

Encouraging online consumers into making better food choices: The power of nature exposure on healthy food choices

BACKGROUND

online environments can influence food desire and choices. We tested if online calming nature and stressful street environments can affect desire for healthy and unhealthy foods.

METHOD

we asked 238 participants (40 ± 14 yrs) to rate their desire (100 mm VAS) for 7 low calorie nutrient rich foods (Healthy) and 7 high calorie nutrient poor foods (Unhealthy), and perceived stress (state anxiety in STAI), before and after imagining themselves in a control, nature park, or busy street condition.

RESULTS

participants who imagined themselves being in a nature park had a significant higher desire for Healthy foods, than participants in the busy street condition (p < 0.05). Participants in the busy street condition decreased their desire for Healthy foods after they imagined themselves in a busy street (p < 0.05)). However, perceived stress did not impact the association between condition and desire for low calorie foods nor high calorie foods.

CONCLUSION

this study suggests that online environments can have an impact on healthy food desires, which could be of importance for the increased number of food choices which are made in online environments.

Neighborhood Resources Associated With Psychological Trajectories and Neural Reactivity to Reward After Trauma

Importance

Research on resilience after trauma has often focused on individual-level factors (eg, ability to cope with adversity) and overlooked influential neighborhood-level factors that may help mitigate the development of posttraumatic stress disorder (PTSD).

Objective

To investigate whether an interaction between residential greenspace and self-reported individual resources was associated with a resilient PTSD trajectory (ie, low/no symptoms) and to test if the association between greenspace and PTSD trajectory was mediated by neural reactivity to reward.

Design, Setting, and Participants

As part of a longitudinal cohort study, trauma survivors were recruited from emergency departments across the US. Two weeks after trauma, a subset of participants underwent functional magnetic resonance imaging during a monetary reward task. Study data were analyzed from January to November 2023.

Exposures

Residential greenspace within a 100-m buffer of each participant's home address was derived from satellite imagery and quantified using the Normalized Difference Vegetation Index and perceived individual resources measured by the Connor-Davidson Resilience Scale (CD-RISC).

Main Outcome and Measures

PTSD symptom severity measured at 2 weeks, 8 weeks, 3 months, and 6 months after trauma. Neural responses to monetary reward in reward-related regions (ie, amygdala, nucleus accumbens, orbitofrontal cortex) was a secondary outcome. Covariates included both geocoded (eg, area deprivation index) and self-reported characteristics (eg, childhood maltreatment, income).

Results

In 2597 trauma survivors (mean [SD] age, 36.5 [13.4] years; 1637 female [63%]; 1304 non-Hispanic Black [50.2%], 289 Hispanic [11.1%], 901 non-Hispanic White [34.7%], 93 non-Hispanic other race [3.6%], and 10 missing/unreported [0.4%]), 6 PTSD trajectories (resilient, nonremitting high, nonremitting moderate, slow recovery, rapid recovery, delayed) were identified through latent-class mixed-effect modeling. Multinominal logistic regressions revealed that for individuals with higher CD-RISC scores, greenspace was associated with a greater likelihood of assignment in a resilient trajectory compared with nonremitting high (Wald z test = -3.92; P < .001), nonremitting moderate (Wald z test = -2.24; P = .03), or slow recovery (Wald z test = -2.27; P = .02) classes. Greenspace was also associated with greater neural reactivity to reward in the amygdala (n = 288; t277 = 2.83; adjusted P value = 0.02); however, reward reactivity did not differ by PTSD trajectory.

Conclusions and Relevance

In this cohort study, greenspace and self-reported individual resources were significantly associated with PTSD trajectories. These findings suggest that factors at multiple ecological levels may contribute to the likelihood of resiliency to PTSD after trauma.

Health and wellbeing benefits of urban forests in winter: a narrative review

Urban trees and green spaces, hereafter, urban forests, are known to contribute to human health and wellbeing. However, research has predominantly focused on warm seasons. To understand whether these benefits extend to winter months, when vegetation is dormant, we conducted a narrative review of the health outcomes associated with urban forests in winter in cities with cold climates. We synthesized findings from 21 studies originating from Asia, Europe and North America. The most studied health outcomes were mental health, physical activity and physiological relaxation, all showing a positive relationship with urban forest exposure. These finding appear similar to those observed in warmer seasons. However, more studies are needed, on a diversity of health outcomes, to draw more robust conclusions in this emerging research field. Future research on urban forests should therefore consider winter and the effect of seasonality to improve health and wellbeing of urban dwellers in all seasons.

How does the macroenvironment influence brain and behaviour-a review of current status and future perspectives

The environment influences brain and mental health, both detrimentally and beneficially. Existing research has emphasised the individual psychosocial 'microenvironment'. Less attention has been paid to 'macroenvironmental' challenges, including climate change, pollution, urbanicity, and socioeconomic disparity. Notably, the implications of climate and pollution on brain and mental health have only recently gained prominence. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

Anatomical Organization of the Amygdala: A Brief Visual Review

The amygdala consists of a collection of nuclei that are deep within the medial temporal lobe. Despite its small size, the amygdala is one of the most densely connected structures in the brain, and it plays a role in many superior neural functions, including neurovegetative control, motor control, memory processing, and neuromodulation. Advances in neuroimaging technology for examining brain activity have opened up new ways of understanding the functional contribution of this structure to emotions, learning, and related memories. Many studies have shown that the amygdala plays a key role in the pathophysiology of neuropsychiatric disorders, such as anxiety disorders, depression, aggression, and temporal epilepsy. This article reviews the anatomical structure of the amygdaloid complex and the connectivity among its subdivisions and with other brain structures, which will serve as a basis for understanding the clinical correlations.

Historical changes in everyday human lifestyles and their effects on hemispheric activation: Speculations on McGilchrist's The Master and His Emissary

McGilchrist [McGilchrist, I. (2009). The master and His emissary: The divided brain and the making of the modern world. Yale University Press] argued that Western society has undergone a population-level shift from greater right hemisphere influence on cognition to increasingly greater left hemisphere influence over the past few centuries. Four historical lifestyle changes that replaced behaviours associated with right hemisphere activation with behaviours associated with left hemisphere activation may be responsible: (i) shifts from standing to sitting, (ii) from being outdoors to indoors, (iii) from communal to solitary activities, and (iv) from analogue/concrete to holistic/abstract representations.

Immersion in nature enhances neural indices of executive attention

There is conjecture that our modern urban environments place high demand on our attentional resources, which can become depleted over time and cause mental fatigue. Natural environments, on the other hand, are thought to provide relief from this demand and allow our resources to be replenished. While these claims have been assessed with self-report and behavioral measures, there is limited understanding of the neural mechanisms underlying these attentional benefits. The present randomized controlled trial fills this gap in the literature by using electroencephalography to explore three aspects of attention-alerting, orienting, and executive control-from a behavioral and neural perspective. Participants (N = 92) completed the Attention Network Task before and after either a 40-min walk in nature or a 40-min walk in a control, urban environment. Participants that walked in nature reported their walk to be more restorative than those that walked in the urban environment. Furthermore, the nature group showed an enhanced error-related negativity after their walk, an event-related brain component that indexes executive control capacity, whereas the urban group did not. These findings demonstrate that a 40-min nature walk enhances executive control at a neural level, providing a potential neural mechanism for attention restoration in nature.

Shinrin-Yoku (Forest Bathing): A Scoping Review of the Global Research on the Effects of Spending Time in Nature

Background

This Scoping review (ScR) builds upon the 2017 review conducted by Hansen et al which contributed to evidence base shinrin-yoku (SY), also known as forest bathing (FB), has many positive health effects and is becoming a prescribed dose (specific time spent in nature) by health care providers. Practice and research regarding SY, has been historically based in Asian countries with a recent increase in Europe. The need and call for more research worldwide continues to further the evidence of SY as a health promotion modality. Through this ScR the authors identified programmatic components, health information monitored and screened, time spent in nature, geographical regions, trends, and themes in SY research worldwide.

Methods

Following PRISMA-ScR guidelines we searched across 7 electronic databases for SY or FB research articles from 2017 through 2022. PubMed, CINAHL, PsycInfo, ScienceDirect, SCOPUS, Embase, JSTOR were included due to the interdisciplinary nature of SY or FB research. Each database provided unique strengths ensuring a capture of a wide range of articles. The resulting articles were screened and extracted through Covidence.

Results

Database searches returned 241 results, with 110 references removed during the deduplication process, 131 were initially screened in the title and abstract review stage. Resulting in 82 unique results deemed relevant and screened in full text. During the final stage of the review, 63 articles met all inclusion criteria and were extracted for data.

Conclusions

The practice of SY has physiological (PHYS) and psychological (PSYCH) benefits across age groups. Research findings indicate either the natural or the virtual environment (VW) has significant health benefits. Continued research is encouraged globally for short- and long-term health outcomes for all individuals. The connection with nature benefits the mind, body and soul and is supported by Henry David Thoreau's philosophy: "Our livesneed the relief of where the pine flourishes and the jay still scream."

Nature-based biopsychosocial resilience: An integrative theoretical framework for research on nature and health

Nature-based solutions including urban forests and wetlands can help communities cope better with climate change and other environmental stressors by enhancing social-ecological resilience. Natural ecosystems, settings, elements and affordances can also help individuals become more personally resilient to a variety of stressors, although the mechanisms underpinning individual-level nature-based resilience, and their relations to social-ecological resilience, are not well articulated. We propose 'nature-based biopsychosocial resilience theory' (NBRT) to address these gaps. Our framework begins by suggesting that individual-level resilience can refer to both: a) a person's set of adaptive resources; and b) the processes by which these resources are deployed. Drawing on existing nature-health perspectives, we argue that nature contact can support individuals build and maintain biological, psychological, and social (i.e. biopsychosocial) resilience-related resources. Together with nature-based social-ecological resilience, these biopsychosocial resilience resources can: i) reduce the risk of various stressors (preventive resilience); ii) enhance adaptive reactions to stressful circumstances (response resilience), and/or iii) facilitate more rapid and/or complete recovery from stress (recovery resilience). Reference to these three resilience processes supports integration across more familiar pathways involving harm reduction, capacity building, and restoration. Evidence in support of the theory, potential interventions to promote nature-based biopsychosocial resilience, and issues that require further consideration are discussed.

Exercise-based rehabilitation in and with nature: a scoping review mapping available interventions

INTRODUCTION

Exercise is an effective component in rehabilitation of a range of chronic conditions. There is a growing interest in the use of exercise-based nature interacted rehabilitation (EBNIR), but an overview of current evidence is missing. The objective of this scoping review was to map existing exercise-based rehabilitation interventions conducted with incidental or intentional nature interaction focusing on its populations, types of outcomes, and theoretical rationale for people with physical and mental disabilities.

METHODS

This scoping review identified peer-reviewed publications, registered upcoming trials and grey literature. To map all available knowledge, a comprehensive search of selected databases (MEDLINE; EMBASE; CINAHL; Cochrane; Web of Science; Pedro) from inception to October 2022. Data were synthesized in a thematic presentation guided by TIDieR, supplemented by a checklist developed for this study accounting nature incidental or intentional interaction.

RESULTS

Twelve studies including 856 participants met the inclusion criteria. Eleven were completed trials and one was registered in clinicaltrials.gov to be run in 2023. A total of 856 patients were enrolled in the 12 studies (range 18-262, median 50). The included studies had great variation. The incidental or intentional interacted exercise-based interventions consisted of outdoor walks, neck exercises and surfing interventions in patients with physical or mental health conditions.

CONCLUSIONS

This scoping review presents an overview of limited and diverse evidence within the field of EBNIR, in patients with physical or mental health conditions. Our review provides an overview that will be helpful in the design of future EBNIR trials.

How does the macroenvironment influence brain and behaviour - a review of current status and future perspectives

The environment influences mental health, both detrimentally and beneficially. Current research has emphasized the individual psychosocial 'microenvironment'. Less attention has been paid to 'macro-environmental' challenges including climate change, pollution, urbanicity and socioeconomic disparity. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

Enlarged housing space and increased spatial complexity enhance hippocampal neurogenesis but do not increase physical activity in mice

Introduction

Environmental enrichment (EE) improves various health outcomes, such as hippocampal neurogenesis, in rodents, which is thought to be caused, in part, by increased physical activity. However, the specific effect of each enrichment component, such as enlarged housing spaces and increased spatial complexity with a variety of objects, on physical activity remains unclear because of methodological limitations in measuring physical activity. We aimed to examine whether enlarged housing spaces and increased spatial complexity increase physical activity in mice using a body-implantable actimeter.

Methods

Adult male C57BL/6J mice were assigned to either standard housing or EE groups. The housing environment in the EE mice was gradually enriched by enlarging the housing space and the placement of a variety of objects. Physical activity was measured using a body-implanted actimeter. Hippocampal neurogenesis was immunohistochemically examined.

Results

Enlarged housing spaces and the placement of a variety of objects did not increase physical activity in mice. In contrast, hippocampal neurogenesis was enhanced in the EE mice, suggesting that environmental interventions successfully provided enriched housing conditions for these mice.

Conclusions

These results indicate that enlarged housing spaces and increased spatial complexity do not increase physical activity in mice. Furthermore, we found that EE enhanced hippocampal neurogenesis without increasing activity volume. Besides the current understanding that increasing the amount of physical activity is key to improving hippocampal function, our result suggests that the environment in which physical activity takes place is also a crucial contextual factor in determining the impact of physical activity on hippocampal function.

Gray space and default mode network-amygdala connectivity

Introduction

Aspects of the built environment relate to health factors and equity in living conditions, and may contribute to racial, ethnic, or economic health disparities. For example, urbanicity is linked with negative factors including exposure to gray space (e.g., impervious surfaces such as concrete, streets, or rooftops). While there is existing research on access to green space and urbanicity on some mental health and cognitive outcomes, there is limited research on the presence of gray space linked with cognitive functioning in youth. The goal of this study was to investigate the link between gray space and amygdala-default mode network (DMN) connectivity.

Methods

This study used data from the ABCD Study. Participants (n = 10,144; age M = 119.11 months, female = 47.62%) underwent resting-state fMRI acquisition at baseline. Impervious surfaces (gray space) were measured via the Child Opportunity Index (COI). To examine the relationship between presence of gray space and -amygdala-DMN (left/right) connectivity, we employed linear mixed effects models. Correlations were run between amygdala-DMN connectivity and internalizing and externalizing symptoms. Finally, post hoc sensitivity analyses were run to assess the impact of race.

Results

More gray space, adjusting for age, sex, and neighborhood-level variables, was significantly associated with increased left amygdala-DMN connectivity (p = 0.0001). This association remained significant after sensitivity analyses for race were completed (p = 0.01). No significant correlations were observed between amygdala-DMN and internalizing or externalizing symptoms.

Discussion

Findings suggest gray space was linked with increased left amygdala-DMN connectivity, circuits that have been implicated in affective processing, emotion regulation, and psychopathology. Thus gray space may be related to alterations in connectivity that may enhance risk for emotion dysregulation. Future investigation of these relationships is needed, as neuroimaging findings may represent early dysregulation not yet observed in the behavioral analyses at this age (i.e., the present study did not find significant relationships with parent-reported behavioral outcomes). These findings can help to inform future public policy on improving lived and built environments.

A randomized controlled pilot study assessing feasibility and safety of a wilderness program for childhood, adolescent, and young adult cancer survivors: the WAYA study

BACKGROUND

The majority of childhood, Adolescent and Young Adult (AYA) cancer survivors suffers from long-lasting health issues following cancer treatment. It is therefore critical to explore effective health promotion strategies to address their needs. Exposure to nature is a promising approach to support the needs of young cancer survivors. This study investigated whether it is feasible to conduct a randomized controlled trial (RCT) of a wilderness program for childhood and AYA cancer survivors.

METHODS

Eligible participants were aged 16-39 years, had a cancer diagnosis, and met minimal criteria. Seventy-one individuals expressed interest and 59 were randomized to either a wilderness or a holiday program. The wilderness program involved an 8-day expedition including backpacking, sea kayaking, gorge climbing, camping, bush-craft skills, and mindfulness-practices. It was followed by a 4-day basecamp after 3 months. The comparison was an 8-day holiday program at a Spa-hotel followed by a 4-day holiday program at the same hotel after 3 months. Primary outcome was study feasibility and safety.

RESULTS

Ultimately, 19 AYAs participated in the wilderness and 23 in the holiday program. All completed the study at one-year follow-up. Participants were mostly female (70%) and represented diverse cancers. Clinical characteristics were similar between study arms excepting greater age at cancer diagnosis in the wilderness program (age 19.1 vs. 12.5; p = 0.024). Program adherence and data completeness was high (> 90%) in both arms. Adverse Effects (AEs) in the wilderness vs. the holiday program were similar (Relative Risk: 1.0, 95% Confidence Interval 0.8-1.3). The most frequent AE was tiredness, all were mild to moderate in severity, and serious AEs were not reported. Nature connectedness significantly increased over time in the wilderness program participants, but not in the holiday program (p < 0.001). No differences were found between the two study arms regarding quality of life, self-esteem, or self-efficacy.

CONCLUSION

It is feasible to conduct a RCT and a supervised wilderness adventure is equally safe for childhood and AYA cancer survivors as a holiday program. This pilot study lays the foundation for a larger RCT to investigate the effectiveness of wilderness programs on the health of young cancer survivors.

TRIAL REGISTRATION DATE AND NUMBER

18/02/2021, NCT04761042 (clinicaltrials.gov).

Exercise therapy for chronic pain: How does exercise change the limbic brain function?

We are exposed to various external and internal threats which might hurt us. The role of taking flexible and appropriate actions against threats is played by "the limbic system" and at the heart of it there is the ventral tegmental area and nucleus accumbens (brain reward system). Pain-related fear causes excessive excitation of amygdala, which in turn causes the suppression of medial prefrontal cortex, leading to chronification of pain. Since the limbic system of chronic pain patients is functionally impaired, they are maladaptive to their situations, unable to take goal-directed behavior and are easily caught by fear-avoidance thinking. We describe the neural mechanisms how exercise activates the brain reward system and enables chronic pain patients to take goal-directed behavior and overcome fear-avoidance thinking. A key to getting out from chronic pain state is to take advantage of the behavioral switching function of the basal nucleus of amygdala. We show that exercise activates positive neurons in this nucleus which project to the nucleus accumbens and promote reward behavior. We also describe fear conditioning and extinction are affected by exercise. In chronic pain patients, the fear response to pain is enhanced and the extinction of fear memories is impaired, so it is difficult to get out of "fear-avoidance thinking". Prolonged avoidance of movement and physical inactivity exacerbate pain and have detrimental effects on the musculoskeletal and cardiovascular systems. Based on the recent findings on multiple bran networks, we propose a well-balanced exercise prescription considering the adherence and pacing of exercise practice. We conclude that therapies targeting the mesocortico-limbic system, such as exercise therapy and cognitive behavioral therapy, may become promising tools in the fight against chronic pain.

[Nature experience and mental health in children-theoretical approaches and selected empirical findings]

The widely documented beneficial effects of children's experiences with nature make it plausible to assume that an environment close to nature also has a positive effect on health in childhood, that is, that it can also contribute to health maintenance and prevention. The findings on health-promoting effects of nature are remarkable and are accentuated and theoretically substantiated here with a focus on mental health.The basis is a so-called three-dimensional personality model, according to which mental development is not only a function of the subject's relationship to other people, but also to the world of things, including nature. In addition, three explanatory approaches for the health effects of nature experiences are outlined: (1) the anthropologically based "Stress Recovery Theory," (2) the "Attention Restoration Theory," and (3) the assumption that nature as a symbolic storehouse for self- and world interpretations can accompany the meaning constitution of the subjects ("Therapeutic Landscapes").The health effects of accessible open spaces close to nature are discussed, whereby the state of research for adults is much richer than for children. With regard to mental health or its influencing variables, the following dimensions are elaborated with empirical results: stress reduction, antidepressant and mood enhancing effects, prosocial behavior, attention and ADHD, cognitive development, self-esteem and self-regulation, nature experience, and exercise. From a salutogenetic perspective, nature does not have a deterministic effect on health, but rather, in a sense, an incidental effect when open spaces close to nature are accessible and used. This casualness of the effect of nature experiences has to be considered in possible therapeutic or educational interventions.

Odor Perception and Descriptions of Rose-Scented Geranium Pelargonium graveolens 'Dr. Westerlund'-Sensory and Chemical Analyses

A recent study found that the natural scent from the rose-scented geranium Pelargonium graveolens 'Dr. Westerlund' had positive effects on stress reduction. Essential oils from many pelargonium species are known to have phytochemical properties and pharmacological activities. No study has, so far, explored and identified the chemical compounds and the sensory perception of these compounds in 'Dr. Westerlund' plants. Such knowledge would be an important contribution to an increased understanding of the effects of plants' chemical odor properties on human well-being, and link this to the expressed perceived scents. This study aimed to identify the sensory profile and suggest responsible chemical compounds of Pelargonium graveolens 'Dr. Westerlund'. The sensory and chemical analysis results revealed sensory profiles of Pelargonium graveolens 'Dr. Westerlund's and provided suggestions for the chemical compounds attributed to the sensory profiles. Further studies are recommended to investigate the correlation between volatile compounds and possible stress reduction in humans.

Psychophysiological mechanisms underlying the effects of outdoor green and virtual green exercise during self-paced walking

Physical activity in the presence of nature can lead to additional, more distinct mental health benefits such as lower stress and anxiety levels and an overall better psychological state when compared to indoor physical activity. Interestingly, the brain mechanisms underlying the effects of green exercise (GE) and virtual green exercise (VGE) on psychological responses are hitherto under-researched. The present study sought to deepen our understanding of the brain mechanisms underlying the effects of GE and VGE during self-paced walking. Thirty individuals took part in the present study. Two experimental (i.e., GE and VGE) and a control condition (CO) were administered in a randomized and counterbalanced order. Participants were asked to walk for ¼ mile at a pace of their choosing and self-report their psychological states at various timepoints during the exercise trials. Heart rate variability and the brain's electrical activity were monitored continuously throughout the experimental protocol. An accelerometer was used to identify the beginning and end of each step. The results indicate that both experimental manipulations were sufficient to influence the majority of psychological and psychophysiological parameters. The most pronounced effects were identified for GE when compared to CO and VGE. VGE was also sufficient to evoke positive emotions and partially reallocate attention externally, although such effects were less pronounced than those observed for GE. The brain mechanisms underlying the abovementioned psychophysiological responses may be associated with significant changes in theta activity throughout the cerebral cortex as well as increased connectivity in the frontal and parietal areas.

The Importance of the Outdoor Environment for the Recovery of Psychiatric Patients: A Scoping Review

(1) Background: Research has shown that patients with mental health diagnoses experience less anxiety and depressive symptoms and higher levels of 'well-being' when they spend time in natural environments as part of their treatment. It has been suggested that there is a relationship between the outdoor settings and the recovery of psychiatric patients. Recovery describes an individual process, which can vary from person to person. (2) Methods: This scoping review examined the relationship between the physical environment and the recovery of psychiatric patients. Systematic searches in three online databases, namely Medline, Embase, and PsycINFO, were performed using a selection of psychiatric, environmental, and recovery terms and included both quantitative and qualitative studies. In general, 'well-being' serves as an overarching indicator when it comes to research on how outdoor settings can affect mental health. Well-being was expressed in terms of mood, social relations, and autonomy. (3) Results: A total of 8138 records were screened, 85 studies were included for full-text reading, and five articles were included in the final analysis. The review showed in general that outdoor settings, more specifically gardening, contact with nature, and a safe environment can be related to the well-being of patients on psychiatric wards. (4) Conclusions: The five reviews allow us to conclude that outdoor settings can be seen as a comprehensive resource for mental health.

Measuring affect and complex working memory in natural and urban environments

Introduction

Research suggests that spending time in natural environments is associated with cognitive and affective benefits, while increased use of technology and time spent in urban environments are associated with depletion of cognitive resources and an increasing prevalence of mental illness. Attention Restoration Theory suggests that exposure to natural environments can restore depleted attentional resources and thereby improve cognitive functioning and mood. Specifically, recent meta-analyses have revealed that the most improved cognitive abilities after nature exposure include selective attention, working memory, and cognitive flexibility.

Methods

While existing studies examined these cognitive abilities, few have examined the Operation Span (OSPAN), a complex measure of working memory capacity. Therefore, the current study (N = 100) compared performance on the OSPAN and self-reported mood using the Positive and Negative Affect Schedule before and after a 30-min walk in a natural or urban environment.

Results

Results from the study showed that both groups exhibited an increase in positive affect and a decrease in negative affect, suggesting that going outside for a walk can boost mood regardless of environment type. Inconsistent with past work, there were no significant changes in OSPAN scores before and after the walk for either environment type.

Discussion

Future studies should analyze how the length of time spent in the environment, certain characteristics of the environment, and individual differences in connectedness to nature may impact attention restoration to gain insight on nature's ability to improve our affect and cognition.

The contour effect: Differences in the aesthetic preference and stress response to photo-realistic living environments

The interest in the response to contours has recently re-emerged, with various studies suggesting a universal preference for curved over angular stimuli. Although no consensus has yet been reached on the reasons for this preference, similar effects have been proposed in interior environments. However, the scarcely available research primarily depends on schematic or unmatched stimuli and faces heterogeneity in the reported results. In a within-subject design, we investigated the claimed contour effect in photo-realistic indoor environments using stimulus material previously tested in virtual reality (VR). A total of 198 online participants rated 20 living room images, exclusively manipulated on the contours (angular vs. curved) and style (modern vs. classic) levels. The scales represented aesthetic (beauty and liking) and stress (rest and stress) responses. Beyond our main focus on contours, we additionally examined style and sex effects to account for potential interactions. Results revealed a significant main effect of contours on both aesthetic (η2g = 1–2%) and stress (η2g = 8–12%) ratings. As expected, images of curved (vs. angular) contours scored higher on beauty, liking, and rest scales, and lower on stress. Regarding interactions with style, curvature was aesthetically preferred over angularity only within images depicting modern interiors, however, its positive effect on stress responses remained significant irrespective of style. Furthermore, we observed sex differences in aesthetic but not in stress evaluations, with curvature preference only found in participants who indicated female as their sex. In sum, our study primarily confirms positive effects of curvature, however, with multiple layers. First, the impact on aesthetic preference seems to be influenced by individual and contextual factors. Second, in terms of stress responses, which might be especially relevant for designs intended to promote mental-health, the consistent effects suggest a more generalizable, potentially biophilic characteristic of curves. To the best of our knowledge, this is the first study to demonstrate these effects in fully-matched, photo-realistic, and multi-perspective interior design stimuli. From the background of a previous VR trial from our research group, whereby the same rooms did not elicit any differences, our findings propose that static vs. immersive presentations might yield different results in the response to contours.

The other blue: Role of sky in the perception of nature

Nature is frequently operationalized as greenery or water to estimate the restorativeness of the environment. Pursuing a deeper understanding of the connection between representation of naturalness and its relationship with restoration, we conducted an experiment aimed to investigate if the sky is perceived as an element of nature. The main goal of this study was to understand how the composition of the environment guides people’s selection of sky as nature in an explicit task. Moreover, we investigated how the amount of visible sky determines this relationship. One hundred five participants participated in a novel explicit judgment task conducted online. In this task, we prepared a set of images trimmed out of 360-degree high dynamic range images. The images were classified according to two primary independent variables representing type of environment (four levels: Nature, Some Nature, Some Urban and Urban) and horizon level (three levels: Low, Medium and High). Each participant was asked to select, by clicking on the image, what they consider as “nature.” In addition, they were asked to judge images on five visual analogue scales: emotional response, aesthetic preference, feeling of familiarity, the openness of the space and naturalness. For analysis, images were segmented into 11 semantic categories (e.g., trees, sky, and water) with each pixel being assigned one semantic label. Our results show that, sky is associated with selections of nature in a specific pattern. The relationship is dependent on the particular set of conditions that are present in the environment (i.e., weather, season of the year) rather than the type of the environment (urban, nature). The availability of sky on the image affects the selection of other nature labels with selections more likely when only a small amount of sky was available. Furthermore, we found that the amount of sky had a significant positive association with the naturalness rating of the whole image, but the effect was small. Our results also indicate that subjective selections of sky predict the naturalness better than trees and water. On the other hand, objective presence of trees and water has a stronger positive association with naturalness while objective presence of sky is positively associated with naturalness. The results show that, relative to its availability sky is considered as nature.

A one-hour walk in nature reduces amygdala activity in women, but not in men

Urban dwellers are more likely to develop mental disorders such as mood and anxiety disorder as well as schizophrenia compared to rural dwellers. Moreover, it has been demonstrated that even short-term exposure to nature can improve mood and decrease stress, but the underlying neural mechanisms are currently under investigation. In the present intervention study we examined the effects of a one-hour walk in an urban vs. natural environment on activity in the amygdala, a brain region previously associated with stress processing. Before and after the walk 63 participants underwent an fMRI paradigm inducing social stress. Since there is a pronounced gap in the literature regarding interindividual differences in stress-related neural effects of urban and natural environments, we set out to explore sex differences. We observed that amygdala activity decreased after the walk in nature, but only in women, suggesting that women may profit more from salutogenic effects of nature. Moreover, performance on the arithmetic tasks improved in women after the walk in nature, whereas men performed better after the walk in the urban environment. To our knowledge, this is the first study to report differencial tendencies in men and women concerning the stress-related neural activity as an effect of acute exposure to urban vs. natural environments. Furthermore, our findings highlight the importance of sex differences when exploring effects of the environment on brain function and stress. Evidence for beneficial effects of nature on stress-related brain regions may inform urban design policies to focus on providing more accessible green areas in cities and this study suggests that sex differences in experiencing the environment should be taken into consideration.