Interplay Between the Physical Environment and the Human Brain: A Review of MRI Research

Past non-human research has consistently demonstrated the profound impact of an animal’s environment on its central nervous system. Over the past decade, various studies have advanced our understanding of how the human brain is linked to its physical surroundings. These studies have employed various methods of operationalising the physical environment, including population density, the outdoor environment, and pollution, as well as diverse study designs, ranging from controlled artificial viewing of pictures to walks in nature. This chapter provides a comprehensive overview of magnetic resonance imaging (MRI) studies probing the relationship between the human brain and environmental factors. Three brain regions consistently emerged across functional MRI and structural MRI investigations: the prefrontal cortex, the amygdala, and the hippocampus. Lifelong and acute exposure to more rural and greener areas may benefit amygdala and prefrontal brain activity and the cortical structure. This beneficial association might be influenced by typically lower levels of social stress in less urbanised environments compared to more urban settings. Moreover, rural environments may provide more opportunities for developing both spatial skills and the hippocampal structure. Fully understanding the causality of these effects remains a critical avenue for future inquiries, focusing on interventional and longitudinal study designs. Comprehending environmental factors that have beneficial or detrimental impacts on our mental and brain health is critical for effective urban planning and health policy development. This synthesis contributes to our understanding of environmental neuroscience and has significant implications for designing healthier living spaces in our increasingly urbanised world.