Effects of Brief Nature Exposure on Brain Functioning and Stress Reactivity

NCT07508800 | Recruiting

• 1 other identifier: UCSF
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This study is focused on understanding the impact of time spent in nature (relative to an urban control) on stress, neural, and cardiac functioning in people experiencing high levels of stress, depression, and anxiety.

Conditions

Stress (Psychology)

Keywords

nature; eeg; reward processing ; attention functioning; stress

Outcome Measures

Primary Outcomes (2)

• Brain functioning

  EEG (neural) measures of attention and reward processing ; resting EEG (including frequency-based analyses of canonical frequency bands, e.g., gamma, beta, alpha, delta, theta) and event-related potential measures (reflecting attention, e.g, P300 and reward/affective processing, e.g., reward positivity, late positive potential).

  ~1 hour after walking condition

• Heart Rate Variability

  This measure reflect the variation in heart beat rate, over time. Specifically we will measure heart rate during the EEG recordings and calculate the RMSSD (Root Mean Square of Successive Differences) of heartbeat R-R intervals.

  ~ 1 hour after walking manipulaation

Study Arms (1)

Within-group study

individuals endorsing current high stress levels

Other: Nature vs. Urban walks

Interventions

Nature vs. Urban walks OTHER

We will evaluate the impact of spending time in nature vs. an urban control on EEG-based measures of reward and attention and resting heart rate variability

Within-group study

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Individuals endorsing high stress levels will be recruited from the community and UCSF clinician outreach through flyer, media advertisements. Current or past depressive and anxiety disorders, if present, will be included due to their high prevalence and overlap with perceived stress.

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• National Institutes of Health (NIH): lead

Study Sites (1)

University of San Francisco California OR San Francisco VA Medical Center

San Francisco, California, 94122, United States

RECRUITING

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: NIH
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: March 17, 2026
• First Posted: April 2, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026
• Last Updated: April 2, 2026

Record last verified: 2026-03

Locations

US (1)