Perceived engagement with nature may be a more consistent predictor of mental health than objectively quantified nature exposureAlthough the mental health benefits of nature are well established, inconsistent operationalization of “nature exposure” remains a limitation in the research, with studies using both perceived and quantified measures. Perceived nature exposure reflects an individual's subjective experience of time spent in natural environments, incorporating factors such as sensory awareness, emotional significance, and personal interpretation. In contrast, quantified nature exposure is based on objective measures of physical presence in natural environments, such as GPS location tracking and land-use metrics (e.g., the normalized difference vegetation index). Few studies have directly compared these two approaches, limiting understanding of whether objective measures can adequately capture the aspects of nature exposure that influence mental health or whether subjective perception plays a distinct role. To address this gap, this study compared how self-reported (perceived) and GPS-logged (quantified) nature exposure related to depression, anxiety, stress, loneliness, and affect among college students over a 15-week semester. The study also examined differences in the mental health outcomes of on-campus and off-campus nature exposure.
The study was conducted at a university in Vermont, U.S., as part of the Lived Experiences Measured Using Rings Study (LEMURS). At the beginning of the fall semester, 548 first- and second-year undergraduate students (age 18 and older) were recruited to participate. Most participants identified as female (71.9%) and White (87.2%), and nearly half were first-year students (48.5%). Bi-weekly surveys were administered at baseline and during weeks 2, 4, 6, 8, 10, 12, and 14 of the semester using a study-specific mobile application (LEMURS app) to assess mental health outcomes and perceived nature exposure. Validated mental health surveys were used to conduct repeated assessments of (1) depression, anxiety, and stress (assessed with the Depression Anxiety Stress Scale); (2) loneliness (assessed with the UCLA Loneliness Scale); and (3) positive and negative affect (assessed with the Positive and Negative Affect Schedule). Weekly nature exposure estimates were calculated using both subjective and objective measures. Perceived (subjective) nature exposure was calculated based on participants' self-reported time in natural environments during the preceding week. Quantified (objective) nature exposure was tracked with a GPS-enabled mobile application (NatureDose<sup>TM</sup>) that logged time spent indoors, outdoors, and near natural environments. The quality of nearby natural settings was assessed using NatureScore<sup>TM</sup>, which integrated numerous remotely sensed environmental variables. Quantified nature exposures were also categorized as total exposure, on-campus exposure, and off-campus exposure. Statistical analysis examined the relationships between perceived nature exposure, quantified nature exposure, and mental health outcomes. Analysis also investigated within-person shifts in the relationship between nature exposure and mental health over time.
Results indicated that higher perceived nature exposure was significantly linked to improved mental health outcomes, including lower depression, stress, and loneliness and higher positive affect, and most of these relationships persisted over time. The relationship between total quantified nature exposure and mental health was weakly associated with worse outcomes but was context-dependent. On-campus nature exposure was associated with somewhat higher stress. However, off-campus quantified nature exposure was significantly, but modestly linked to reduced stress and loneliness. When perceived and quantified nature exposure were combined in a statistical model, perceived exposure remained the stronger predictor of mental health outcomes. Finally, the relationship between perceived nature exposure and improved mental health did not vary by level of objectively measured exposure. This finding suggests that the relationships between perceived nature exposure and mental health, and between quantified nature exposure and mental health, are largely independent.
As one of the first studies to directly compare perceived and objectively quantified nature exposure, this study advances understanding of how different measures of nature exposure relate to mental health. Overall findings suggest that perceived engagement with nature is a more consistent and robust predictor of mental health among college students than objectively quantified exposure, highlighting the importance of the quality of the experience rather than time spent in nature alone. Differences between on- and off-campus exposure further suggest that the restorative effects of nature depend on context and the opportunities it provides, particularly for psychological disengagement from academic, social, and digital demands. “These findings underscore the need to move beyond exposure quantity toward a more nuanced understanding of the cognitive and emotional processes through which nature supports well-being.” Universities should prioritize mental health initiatives that foster meaningful engagement with nature, including off-campus natural areas.
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