Cognitive mechanisms underlying how exposure to nature influence well-being

Healthy volunteers will be randomly assigned to six different levels of nature exposure, and researchers will track their daily well-being over three months using self-reports, pupil dilation, movement sensors, and stress hormone levels. This matters because while many people feel better after a walk in the park, the underlying cognitive and biological mechanisms remain poorly understood. Without knowing *why* nature improves mood, it is difficult to design effective interventions or prescribe nature exposure with confidence—for example, to urban planners, clinicians, or employers seeking evidence-based ways to support mental health. If this research succeeds, it will provide concrete, testable hypotheses about how nature shifts attention, emotional bias, and decision-making. This could eventually inform public health guidance on the minimum "dose" of nature needed for measurable benefit, or help design urban green spaces that maximise psychological impact. The study is a fundamental experimental medicine investigation—it will not deliver an immediate practical tool, but it will lay the groundwork for future case-control trials that could turn nature exposure into a prescribed, quantified intervention for conditions like depression or chronic stress.