Periodic Reporting for period 1 - BrainScape (How the physical environment shapes the human brain)
Période du rapport: 2023-07-01 au 2025-12-31
Amid accelerating urbanization, climate change and other environmental challenges worldwide, BrainScape addresses a critical research gap: how and to what extent daily exposure to our surroundings shapes brain structure and function. While previous research on brain plasticity has mainly focused on lifestyle and social factors, BrainScape breaks new ground by exploring the environmental determinants of brain health.
Its goals are to identify the relevant “active ingredients” in the environment by introducing a more holistic understanding of the environment as a multi-layered complex phenomenon, and to gain insight into the precise pathways and mechanisms by which the environment affects the brain and mental health. To do so, BrainScape is divided into four work packages (WPs):
WP1 uses existing large-scale European brain imaging datasets (e.g. UK Biobank, NAKO, IMAGEN) to examine how multiple environmental features jointly affect the brain and mental health. In order to determine the most salient features of the physical environment we use a geographic information systems (GIS) approach to quantify specific features surrounding the home – stepping beyond simplistic dichotomies of urban vs. rural.
WP2 uses a unique twin study design to disentangle environmental effects from genetics by comparing monozygotic twins living in different environments, and thereby testing the most important effects identified in WP1.
WP3 tracks short-term environmental exposures (e.g. time spent outdoors, pollution) and their link to rapid brain changes using wearable sensors and high-resolution imaging, to address the effects of day-to-day environmental variations.
WP4 brings participants into lab-based, immersive virtual environments using VR to test the specific effects of sights, sounds, and smells of nature on brain function.
By uncovering whether and how the physical environment – including factors such as green spaces, pollution levels, noise and light exposure – affects the human brain, mental health and well-being, BrainScape, we hope, can ultimately lead to targeted adaptations – which are easier to scale to larger populations than commonly applied lifestyle interventions (for example, smoking-cessation programmes) – resulting in more far-reaching and sustainable effects. Insights from BrainScape will have implications for urban planners, architects, health professionals and policymakers looking to make more salutogenic environments for all.
Its goals are to identify the relevant “active ingredients” in the environment by introducing a more holistic understanding of the environment as a multi-layered complex phenomenon, and to gain insight into the precise pathways and mechanisms by which the environment affects the brain and mental health. To do so, BrainScape is divided into four work packages (WPs):
WP1 uses existing large-scale European brain imaging datasets (e.g. UK Biobank, NAKO, IMAGEN) to examine how multiple environmental features jointly affect the brain and mental health. In order to determine the most salient features of the physical environment we use a geographic information systems (GIS) approach to quantify specific features surrounding the home – stepping beyond simplistic dichotomies of urban vs. rural.
WP2 uses a unique twin study design to disentangle environmental effects from genetics by comparing monozygotic twins living in different environments, and thereby testing the most important effects identified in WP1.
WP3 tracks short-term environmental exposures (e.g. time spent outdoors, pollution) and their link to rapid brain changes using wearable sensors and high-resolution imaging, to address the effects of day-to-day environmental variations.
WP4 brings participants into lab-based, immersive virtual environments using VR to test the specific effects of sights, sounds, and smells of nature on brain function.
By uncovering whether and how the physical environment – including factors such as green spaces, pollution levels, noise and light exposure – affects the human brain, mental health and well-being, BrainScape, we hope, can ultimately lead to targeted adaptations – which are easier to scale to larger populations than commonly applied lifestyle interventions (for example, smoking-cessation programmes) – resulting in more far-reaching and sustainable effects. Insights from BrainScape will have implications for urban planners, architects, health professionals and policymakers looking to make more salutogenic environments for all.
Within WP1, we have conducted several analyses on the large-scale datasets. Using data from the UKBiobank we have been able to demonstrate that the volume of the hippocampus is predicted by several indicators of air pollution at participants‘ home address, and interestingly, that the amount of green space around the home address is an additional predictor, adding further explained variance above and beyond the air pollution measures (Drewelies et al., 2024). Furthermore, we are in the process of publishing a paper which shows, on UKBiobank data, that the outcome measure of depressive symptoms (at similar neuroticism levels) are best predicted by risk factors such as living in a deprived neighbourhood and stressful life events; hours spent outdoors in summer, meanwhile, turned out to be a protective factor using random forest analyses (Fiedler et al., submitted).
Our paper on IMAGEN data, a European-wide neuroimaging dataset, was able to show that changes in brain structure during adolescence (from 14–22 years of age) are predicted by changes in environmental variables such as air pollution, tree cover density and presence of bodies of water (Quinones et al., submitted). The main analyses on the HCHS study are ongoing, but will lead to a submitted paper shortly. A manuscript that we will submit soon contains an analysis of a subsample of n=200 participants on whom we conducted a neurotoxicological screening of blood probes (Braun et al., 2024, Science). Here we linked the detection of different toxins to brain structure, observing that endogenous chemicals seem to be associated positively with brain structure, while human-made chemicals seem to be more negatively associated with brain structure (Kühn et al., submitted).
Within WP2, we will finish data collection of the first assessment wave in August 2025. Here we have tested 150 monozygotic twin pairs (n=300 individuals) and characterized their living environment as well as their brain structure and function. This is a major achievement, since contrary to our original plans, only a fraction of the twin participants came from the TwinLife cohort. We therefore had to find additional ways of recruiting twin pairs in Germany. As a byproduct of this effort, we have now started building the first German twin registry (www.gertrud.info).
Within WP3 we have already collected half of the sample (n=15 individuals), who underwent MRI testing for 25 sessions each, with environmental assessments 24h before entering the scanner. A written study design paper is now under submission to enable optimal data sharing once the sample is complete (n=30 individuals) (Falkenstein et al., submitted).
Within WP4, we tested the effects of the different modalities sight, sound and smell, and explored in particular whether any outcome measures show that the sum of experience is more than its parts. We observed exactly that, namely supra-additive effects of the joint exposure to sight, sound and smell of the forest in virtual reality (VR) on self-reported positive affect and nature connectedness (Ascone et al., 2025). Simultaneously, we ran an experimental study in which we explored the potential associations between the concept of forest and anxiety, because although we observed several potential positive effects of forest exposures, participants did mention some anxieties, in particular when we drove them to the real-life forest exposure. In an implicit study design we compared the picture categories forest, park and houses, yielding mixed results (Fischer et al., 2024) that practitioners in clinical settings should consider.
Our paper on IMAGEN data, a European-wide neuroimaging dataset, was able to show that changes in brain structure during adolescence (from 14–22 years of age) are predicted by changes in environmental variables such as air pollution, tree cover density and presence of bodies of water (Quinones et al., submitted). The main analyses on the HCHS study are ongoing, but will lead to a submitted paper shortly. A manuscript that we will submit soon contains an analysis of a subsample of n=200 participants on whom we conducted a neurotoxicological screening of blood probes (Braun et al., 2024, Science). Here we linked the detection of different toxins to brain structure, observing that endogenous chemicals seem to be associated positively with brain structure, while human-made chemicals seem to be more negatively associated with brain structure (Kühn et al., submitted).
Within WP2, we will finish data collection of the first assessment wave in August 2025. Here we have tested 150 monozygotic twin pairs (n=300 individuals) and characterized their living environment as well as their brain structure and function. This is a major achievement, since contrary to our original plans, only a fraction of the twin participants came from the TwinLife cohort. We therefore had to find additional ways of recruiting twin pairs in Germany. As a byproduct of this effort, we have now started building the first German twin registry (www.gertrud.info).
Within WP3 we have already collected half of the sample (n=15 individuals), who underwent MRI testing for 25 sessions each, with environmental assessments 24h before entering the scanner. A written study design paper is now under submission to enable optimal data sharing once the sample is complete (n=30 individuals) (Falkenstein et al., submitted).
Within WP4, we tested the effects of the different modalities sight, sound and smell, and explored in particular whether any outcome measures show that the sum of experience is more than its parts. We observed exactly that, namely supra-additive effects of the joint exposure to sight, sound and smell of the forest in virtual reality (VR) on self-reported positive affect and nature connectedness (Ascone et al., 2025). Simultaneously, we ran an experimental study in which we explored the potential associations between the concept of forest and anxiety, because although we observed several potential positive effects of forest exposures, participants did mention some anxieties, in particular when we drove them to the real-life forest exposure. In an implicit study design we compared the picture categories forest, park and houses, yielding mixed results (Fischer et al., 2024) that practitioners in clinical settings should consider.
Borne out of the challenge that fewer twin participants from the previous TwinLife study wanted to participate in our laboratory study for WP2, we had to search for new recruitment pathways and so founded the first Germany-wide twin registry, Gertrud, along with our cooperation partners, the University of Bielefeld, Medical School Hamburg, Max Planck Institute for Empirical Aesthetics, Saarland University and University Hospital Tübingen. It lays the foundation for a unified registry of German twins, following the model of renowned registries in Sweden, Australia, and the United Kingdom. We have applied for funding from the Max Planck Society to secure the registry a stable, longer-term future.
Within the Day2Day Environment study (WP3) we are currently collecting a precious dataset that – if utilized by the scientific community as our first Day2Day dataset has been – will create a wealth of new knowledge, as it enables the investigation of short-term associations between environmental exposures and brain- and mental health-related outcomes in an ecologically valid setting. Having this many within-subject repeated measurements is clearly novel, and is unprecedented with the level of environmental phenotyping that we have gathered. It will enable us to identify environmental exposure factors that influence human brain and mental health in a relatively acute way.
Within the Day2Day Environment study (WP3) we are currently collecting a precious dataset that – if utilized by the scientific community as our first Day2Day dataset has been – will create a wealth of new knowledge, as it enables the investigation of short-term associations between environmental exposures and brain- and mental health-related outcomes in an ecologically valid setting. Having this many within-subject repeated measurements is clearly novel, and is unprecedented with the level of environmental phenotyping that we have gathered. It will enable us to identify environmental exposure factors that influence human brain and mental health in a relatively acute way.