Effects of Brief Nature Exposure on Brain Functioning and Stress Reactivity

Associations between urbanization and mental illness have long been recognized, but the mechanistic pathways underlying this association are not well understood and likely multifactorial. Reduced contact with nature may contribute to the increased psychopathology observed in urban environments.

Theories implicating attention restoration and stress reduction functions via cognitive control and reward brain networks have been proposed to explain how natural environments may decrease stress and promote mental health, particularly in individuals with high-stress loads who are at-risk for developing mental illness. However, most research examining nature's effects on mental health have been observational in design, leaving open questions about nature's effects on neural functioning. Well-controlled studies of brain responses to natural environments will inform stakeholders about potential cognitive and health benefits of nature, as well as guide development of clinical applications like parks prescriptions and nature-based behavioral interventions for individuals who may benefit. This team science grant will enable pilot data collection and a novel collaboration combining faculty expertise in pediatric nature-basedinterventions, clinical neuroscience of reward and motivation, electrophysiological biomarkers of psychiatric vulnerability and integrative healthcare. Further, our team will tap the policy and stewardship expertise of parks system leadership. This project's goal is to conduct a pilot clinical neuroscience study to establish a novel academic-community collaboration and support a larger project proposal to examine neurophysiological mechanisms underlying nature-based clinical interventions to improve mental health in individuals experiencing stress-based symptoms.

Inclusion criteria

• Meets cut-off for high level of perceived stress on PSS-10 during screening (>27 total score); Current or past depressive and anxiety disorders, if present on SCID-5 assessment, will be ncluded due to their high prevalence and overlap with perceived stress
• Normal, or corrected to normal, vision (due to the visual nature of the EEG tasks)
• If on psychotropic medication, stable regime for > 1 month

Exclusion criteria

• Major medical conditions with CNS sequelae (e.g., seizure disorders, multiple sclerosis, significant, uncontrolled cardiovascular pathology) Past or present neurological problems (including seizures and head trauma resulting in neurological or cognitive sequelae)
• IQ estimate <75 on the Test of Premorbid Functioning
• Current or past history of severe mental illness (e.g., bipolar schizophrenia spectrum disorder, or current or past history of substance use disorders