A systematic review of the impacts of nature exposure on the nervous system in children and youth: Implications for nature-based learning

The neurobiological correlates of nature exposure in children and youth, from primary school students to undergraduates, remain poorly understood. This article aims to bridge this gap by conducting a systematic review, targeting studies that investigated the impact of any form of nature exposure on the brain and/or peripheral nervous system in neurotypical individuals aged under 25. A total of 26 articles were retrieved following a search using PRISMA guidelines through the Children & Nature Network Research Library, APA PsycNet, Scopus, CINAHL, EMBASE and Medline databases. Except for brain structure outcomes, the studies were analyzed depending on whether measurements were conducted in exposure-only conditions or in exposure plus physical or cognitive task conditions. We found that nature exposure in children and youth was associated with changes in brain structure, specifically increased prefrontal cortex grey matter volume. In exposure-only conditions, peripheral nervous system activity and brain activity were associated with a "relaxed yet alert" state, as reflected by lower sympathetic activity, higher parasympathetic activity, a decrease in prefrontal cortex activity and brain waves with the exception of beta power which increases, when compared to urban or indoors conditions. In exposure plus physical task engagement, brain activity was also associated with relaxed and meditative states. Nature exposure plus cognitive task engagement was associated with an increase in brain activity, which reflects improvements in attentional processing and cognitive resource allocation. These findings support the use of nature-based learning beyond pre-K and primary education until the age of 25, as older teenagers and young adults might also experience learning benefits due to nature exposure. • The neurobiological correlates of nature exposure in children and youth are poorly understood • Nature exposure is associated with increased grey matter volume in the prefrontal cortex • In exposure-only conditions, nature exposure is associated with relaxation as reflected by decreased brain activity, lower sympathetic activity and higher parasympathetic activity, as well as with alertness as reflected by increased beta power • In exposure plus cognitive task engagement, nature exposure is associated with enhanced attentional processing and cognitive resource allocation • Results are comparable across all age groups included in the review