Hugo J. Spiers

The literature is ambivalent about the relationship between urban greening and health but generally reports positive associations for mental health and wellbeing (MHWB). It also notes that how street greening – a commonly used urban intervention – is experienced and impacts MHWB in real settings remains less studied and the evidence basis that guides urban planning is limited. Meantime, urban policy and practice treat urban greening as a near-universal solution for better quality of life. This paper studies street greening in situ and examines such policy claims empirically. It does so through a field experiment at two matched intervention-control site pairs in London. Each intervention site received planting and public-realm improvements in 2025. 215 participants were surveyed before and after the intervention, six months apart, using a WHO-5-aligned tool to assess experiential indicators associated with subjective MHWB. This is the first field experiment designed to document street greening's experiential effects in real settings. Based on a paired comparison, the paper finds that (1) street greening was experienced differently at the two sites, and (2) its effects were correspondingly uneven: at one site, greening was associated with improvements in experiential indicators linked to MHWB, while at the other the association was negligible. The paper suggests that the scale and design of interventions, their connectivity to the green infrastructure network and their streetscape are candidate explanations for such difference. The findings suggest that street greening may not consistently translate into MHWB benefits and point to the importance of context-sensitivity in policy and practice.

NMDAR and LGI1 encephalitis are the two most common forms of autoimmune encephalitis and are associated with persistent cognitive sequelae, particularly episodic memory impairment. Patients also report lasting difficulties with spatial orientation and navigation, yet these symptoms remain poorly characterized. Both disorders affect neural systems supporting spatial navigation, including prominent hippocampal pathology alongside cingulate, temporo-parietal, thalamic and cerebellar alterations identified in advanced neuroimaging studies. Here, we therefore investigated the frequency and clinical relevance of spatial navigation impairment in post-acute NMDAR and LGI1 encephalitis, its relationship with episodic memory dysfunction, and its structural correlates. We included 80 post-acute patients from the autoimmune encephalitis outpatient clinic at Charité – Universitätsmedizin Berlin: 50 with NMDAR encephalitis (mean age 35.0 years, range 19-71; 90% female; median 6.9 years from onset) and 30 with LGI1 encephalitis (mean age 63.6 years, range 33-84; 67% male; median 2.7 years from onset). Spatial navigation was assessed using a passive map-assisted task (VIENNA Young) and an active wayfinding task (Sea Hero Quest), and its relationship with verbal episodic memory was examined using the Rey Auditory Verbal Learning Test. Structural MRI analyses assessed cortical thickness, subcortical volumes and diffusion measures in preselected navigation- and memory-related regions. Patients with NMDAR and LGI1 encephalitis performed worse than matched controls on map-assisted navigation, and navigation performance showed strong convergence across the two navigation paradigms. Norm-referenced navigation impairment affected 57% of patients with NMDAR encephalitis and 70% with LGI1 encephalitis. In NMDAR encephalitis, selective navigation impairment was more common than selective memory impairment (41% versus 14%; χ ² = 6.26, p = .012), supporting partial dissociation. In LGI1 encephalitis, navigation and memory impairments were similarly frequent and strongly overlapping, with 53% of patients impaired in both domains. Older age was a shared risk factor for navigation impairment. Structurally, NMDAR encephalitis showed partly distinct navigation- and memory-related alteration patterns, with navigation-specific parietal-paracentral and cerebellar abnormalities and memory-specific temporal-hippocampal-thalamic involvement. LGI1 encephalitis showed more widespread, predominantly memory-related alterations without a robust navigation-specific structural signature. Our findings identify spatial navigation as a frequently affected but under-assessed cognitive domain in post-acute NMDAR and LGI1 encephalitis. They provide clinical evidence that navigation and episodic memory are partially dissociable yet overlapping functions whose degree of separability varies with the extent and distribution of network pathology. Incorporating norm-referenced navigation assessment into longitudinal follow-up could improve the characterization of cognitive profiles and related support needs, while reducing the risk that impairments relevant to everyday functioning and long-term quality of life remain undetected.

Much of our knowledge is structured in networks, but how the brain represents such networks remains unclear. In most nested knowledge structures a subset of the nodes will be highly connected to other nodes in the network. High levels of connection can exist either locally (high degree centrality) or at a global level (high closeness/betweenness centrality). Here, we explored how the human brain represents network structure using functional magnetic resonance imaging (fMRI) and a novel learning paradigm. During training, participants learned the transition structure for travel between a set of fictious partially connected alien planets. Despite encountering only individual connections, participants choices indicated they could infer the broader network structure. Next day, they viewed each stimulus during a cover task while undergoing fMRI. Representational-similarity analysis showed that shortest-path distances within the learned graph were encoded in the posterior hippocampus and right retrosplenial complex, whereas global connectivity (closeness/ betweenness centrality) was represented in the left retrosplenial complex. These findings extend the view that brain networks associated with spatial navigation also process abstract relational knowledge using principles akin to mapping physical space. The results are also consistent with proposals that the hippocampus represents distance information and that the retrosplenial cortex acts as hub for integrating recently acquired knowledge.

Orca, wolves, chimpanzees and humans share a similarly impressive capacity for group hunting, where individuals coordinate behaviour together to capture prey. Studying hunting behaviours has important implications for understanding how behaviour in group contexts may be indicative of cognitive decline. Despite growing interest in brain circuits for prey capture, the brain regions involved in tracking prey during a hunt and the behaviours in group hunt linked to success remain unclear. Here we combined functional near infrared spectroscopy (fNIRS) and a virtual minecraft world to examine behaviour, brain dynamics and brain synchrony involved in group hunting behaviour. We focused on the prefrontal cortex (PFC) due to its known role in planning and social coordination and recorded from pairs of individuals as they either cooperated to hunt another person (prey) or simply followed another person. Hunters were more successful if they managed to keep a smaller distance to the prey and moved at speeds that were more synchronised with their co-predator. At high-range frequencies for fNIRS (0.1-0.2Hz), we found greater brain-to-brain synchrony in lateral and medial (frontopolar) PFC regions during hunting compared with chance levels. Together, these findings provide insights into what behaviours and brain dynamics associated with successful group hunting.

The health benefits of urban green space are widely discussed in the literature, however, there is limited evidence and field experiments on how street-level green interventions affect mental health and well-being (MHWB) outcomes. Such experiments are notoriously difficult due to the complex nature of urban environments, which makes it challenging to identify and match control sites to intervention sites with precision. This paper addresses this challenge by outlining a methodological framework for such matching and tests its validity by piloting the NeuroDesign Index Urban (NDIX-Urban) in two real-life before-and-after street redevelopment projects in North London. The framework draws on health and streetscape research that identifies key neighbourhood- and street-level characteristics influencing MHWB in urban contexts. These characteristics underpin a multi-level, spatially layered approach. First, neighbourhoods are filtered using QGIS-based analysis of socio-economic status, crime and safety levels, land use, and green coverage. Second, environmental audits and site visits are conducted at street level to identify similar control sites in terms of traffic flow, pedestrian activity, and the type and quality of buildings. The matching of control and intervention sites is validated using the NDIX-Urban survey, administered to 122 participants. Data from the four sites was analysed to assess the framework’s effectiveness in selecting highly comparable control sites, based on NDIX-Urban categories, including safety and accessibility, sensory, emotional, cognitive, social, and naturalness. The paper concludes that the control site selection procedure developed within the framework is robust, providing a spatial and structured methodology for future urban field experiments.

Architectural experience involves processing the spatial layout of an environment and our emotional reaction to it. However, these two processes are largely studied separately. Here, we used fMRI and first-person movies of journeys through buildings and cities to determine the contribution of different brain regions to spatial and aesthetic aspects of the built environment. During scanning, participants watched 48 movies that show first-person-view travel through different spaces; immediately after each video, they either judged the spatial layout complexity or valence of the environment. After scanning, participants took part in a debrief session that revealed how memorable each space encountered was. Activity in brain regions previously linked to valence processing (e.g., ventromedial pFC) was modulated by aesthetic qualities of the stimuli (i.e., increased for pleasant spaces compared to unpleasant spaces) and the task (more active when judging valence), whereas activity in brain regions linked with spatial processing (e.g., parahippocampal regions) increased in complex layouts compared to simple layouts. The hippocampus and parahippocampal cortex were associated with the memorability of spaces and were modulated by both aesthetic and spatial qualities. We also tested for curvature, fascination, coherence, and hominess—qualities linked to aesthetic judgement in architecture. We replicated findings activating right lingual gyrus for fascination, left inferior occipital gyrus for coherence, and left cuneus for hominess and found inverse computational curvature activated spatial, valence, and visual processing regions. Overall, these findings provide important insights into how different brain regions respond while experiencing new buildings and city spaces, which is needed to advance the field of neuroarchitecture.

The built environment shapes physical and mental health. In this paper we use the term mental health as an overarching construct, defined here as encompassing both cognitive performance and affective wellbeing, explored in relation to environmental factors. Evidence across neuroscience, psychology, physiology, and public health shows that spatial properties of our environment can modulate stress physiology, affect, attention, memory, and social cognition. Yet, no standardised instrument translates these multisensory dynamics into measures that quantify environmental qualities, enabling linking them to context-specific outcomes. Certification schemes (e.g., WELL, LEED, BREEAM) have advanced practice, but do not directly measure how specific spatial or contextual features impact psychology or physiology. Here, we introduce the NeuroDesign/NeuroArchitecture Index (NDIX), a theoretically grounded framework for evaluating how the built environment impacts mental health. The NDIX operationalises six domains; safety and accessibility, cognitive capacity, offering possibilities for sensory experiences, emotional states, social experiences, and naturalness. It integrates a domain-referenced self-report of user experience with standardised profiling of environmental features, generating domain specific and overall percentage scores for research and practice. The first pilot in a controlled indoor environment showed feasibility and theory-consistent sensitivity, providing initial support for the NDIX framework. Future research will extend validation across office, educational, and urban contexts and incorporate biomarkers (e.g. from wearables, neuroimaging).

There has been unprecedented progress in artificial intelligence (AI), yet most current AI systems are trained on data from Western, industrialised societies. This narrow focus limits the generalisability and adaptability of AI models, which fail to reflect the full spectrum of human cognition and culture. Moreover, heavy dependence on pre-existing data overlooks how learning occurs in the wild, through direct interaction and feedback from the environment, and constrains innovation. Here, we integrate insights from anthropology, cognitive science, and computer science to argue for a broader, ecologically grounded approach to AI development. We examine examples from traditional cultures, particularly extant hunter-gatherers, whose modes of living reflect the ecological and social conditions under which human cognition evolved. These communities offer underexplored but highly relevant perspectives on core challenges in AI, from multimodal sensory perception to embodied and experiential learning and collective intelligence. These comparisons not only offer conceptual tools for AI design but also invite reflection on the reverse question: what can building AI teach us about human cognition, especially when inspired by ecologically diverse strategies? To develop embodied AI systems capable of engaging meaningfully with the world’s sensory and interactive richness, we must look to those who have long done so.

There is consistent evidence for a positive association between education and a wide range of cognitive abilities. In particular, spatial abilities have been shown to be strongly related to academic achievement. However, studying this association is complex as both education and spatial abilities are modulated by multivariate sociodemographic factors, likely to vary across countries. Most previous studies relied on small sample sizes or were restricted to a limited number of countries, thus were unable to control for these covariates. To overcome these limitations, we used a spatial navigation task embedded in a mobile video game. We quantified the wayfinding ability of 397,162 people across 38 countries and showed that on average, education level was positively associated with wayfinding ability. This difference was stronger in older participants and increased with task difficulty. However, the effect of education was different across countries, from near-zero and non-significant in India (Bayes’ factor = 0.08, Hedge’s g = −0.03, 95% CI = [−0.15, 0.08]), to modest and significant in Romania (Bayes’ factor = 345.44, Hedge’s g = 0.15, 95% CI = [0.08, 0.22]). We did not find any relationship between the education effect size of countries and economic indicators such as GDP per capita. Using the 1972 reform increasing the minimum school leaving age in the UK as a natural experiment, we used a regression discontinuity design to show that education has a causal effect on wayfinding ability.