Purpose of Review
Given the global burden of mental health issues, new solutions are needed to promote mental health. Nature exposure represents a promising option to promote mental health, but the mechanisms are poorly understood. Recent frameworks have argued that changes in mental health in nature are caused by activity changes in the vagus nerve, which connects the heart and the brain, and that these changes also improve executive functioning (EF) abilities. This suggests that changes in mental health symptomology in nature should be accompanied by changes in vagus nerve activity, as well as changes in executive functioning. Yet, little work has systematically examined co-variation of these outcomes in empirical studies. The present manuscript systematically examines whether changes in mental health in nature are accompanied by changes in vagus nerve activity (approximated by heartrate variability) and changes in executive functioning.
There is compelling evidence that spending time in nature can increase heartrate variability, improve mental health, and improve executive functioning. However, despite strong theoretical claims that these three outcomes should be linked after spending time in nature settings, few studies directly examine such co-occurrence.
The study systematically examines whether studies that considered both mental health and executive functioning (n = 6) showed co-occurring effects in response to nature exposure. Similarly, the study also considers if studies examining mental health and heartrate variability (n = 6) showed similarly directional effects following nature exposure. This systematic review concludes with discussion about the limited number of studies (n =1) that include all three measures. We find mixed results of co-occurrence with these variables, suggesting that the relationship between these three constructs in nature may be more nuanced than current theory suggests. Perhaps more importantly, our results demonstrate that there is very little existing work linking changes in mental health to changes in EF and vagal tone. We conclude with justification for why it may be beneficial for researchers to include all three metrics as well as guidance on how to do so.
This is a preview of subscription content,to check access.
Access this article
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
Bettmann JE, Hanley AW. The effects of nature-immersive experiences on social, mental, and physical health in adults with mental illness or symptoms of mental illness. Fort Collins, CO: SHIFT Summit; 2022.
Tillman S, Tobin D, Avison W, Gilliland J. Mental health benefits of interactions with nature in children and teenagers: a systematic review. J Epidemiol Community Health. 2018;72:958–66. https://doi.org/10.1136/jech-2018-210436.
Min K, Kim H, Kim H, Min J. Parks and green areas and the risk for depression and suicidal indicators. Int. J. Public Health. 2017;62:647–56. https://doi.org/10.1007/s00038-017-0958-5.
Groenewegen P, Van den Berg AE, De Vries S, Verheij RA. Vitamin G: effects of green space on health, well-being, and social safety. BMC Public Health. 2006;6:149. https://doi.org/10.1186/1471-2458-6-149.
Santomauro DF, Herrera AMM, Shadid J, Zheng P, Ashbaugh C, Pigott DM, Ferrari AJ. Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. Lancet. 2021;398:1700–12. https://doi.org/10.1016/S0140-6736(21)02143-7.
Al-Harbi KS. Treatment-resistant depression: therapeutic trends, challenges, and future directions. Patient Prefer Adherence. 2012:369–88. https://doi.org/10.2147/PPA.S29716.
Kaplan S. The restorative benefits of nature: toward an integrative framework. J Environ Psychol. 1995;15:169–82. https://doi.org/10.1016/0272-4944(95)90001-2.
Ulrich R, Simons R, Losito B, Fiorito E, Miles M, Zelson M. Stress recovery during exposure to natural and urban environments. J. Environ. Psychol. 1991;11:201–30. https://doi.org/10.1016/s0272-4944(05)80184-7.
• Scott E, McDonnell A, LoTemplio S, Uchino B, Strayer D. Toward a unified model of stress recovery and cognitive restoration in nature. PSF. 2021:37. https://doi.org/10.5070/P537151710. Framework that links disparate theories of health improvements in nature
Jecmen D, LoTemplio S. Improvements in depressive symptoms in nature may be partly caused by improvements in vagal tone: a review and theoretical perspective. Ecopsychology. 2023. https://doi.org/10.1089/eco.2023.0007.
Laborde S, Mosley E, Thayer JF. Heart rate variability and cardiac vagal tone in psychophysiological research–recommendations for experiment planning, data analysis, and data reporting. Front Psychol. 2017;8:213. https://doi.org/10.3389/fpsyg.2017.00213.
Diamond A. Executive functions. Annu Rev Psychol. 2013;64:135–68.
Miyake A, Friedman NP. The nature and organization of individual differences in executive functions: four general conclusions. Curr Dir Psychol Sci. 2012;21:8–14. https://doi.org/10.1177/0963721411429458.
• Stevenson MP, Schilhab T, Bentsen P. Attention Restoration Theory II: a systematic review to clarify attention processes affected by exposure to natural environments. J Toxicol Environ Health B Crit Rev. 2018;21:227–68. https://doi.org/10.1080/10937404.2018.1505571. Comprehensive meta-analysis of nature and EF
Ohly H, White MP, Wheeler BW, Bethel A, Ukoumunne OC, Nikolaou V, Garside R. Attention restoration theory: a systematic review of the attention restoration potential of exposure to natural environments. J Toxicol Environ Health B Crit Rev. 2016;19:305–43. https://doi.org/10.1080/10937404.2016.1196155.
LoTemplio SB, Scott EE, McDonnell AS, Hopman RJ, Castro SC, McNay GD, et al. Nature as a potential modulator of the error-related negativity: a registered report. Int J Psychophysiol. 2020;156:49–59. https://doi.org/10.1016/j.ijpsycho.2020.06.014.
Hopman RJ, LoTemplio SB, Scott EE, McKinney TL, Strayer DL. Resting-state posterior alpha power changes with prolonged exposure in a natural environment. Cogn Res Princ Implic. 2020;5:1–13. https://doi.org/10.1186/s41235-020-00247-0.
Cambridge OR, Knight MJ, Mills N, Baune BT. The clinical relationship between cognitive impairment and psychosocial functioning in major depressive disorder: a systematic review. Psychiatry Res. 2018;269:157–71.
Shields GS, Moons WG, Tewell CA, Yonelinas AP. The effect of negative affect on cognition: anxiety, not anger, impairs executive function. Emotion. 2016;16(6):792.
Brown TE. ADD/ADHD and impaired executive function in clinical practice. Curr Atten Disord Rep. 2009;1(1):37–41.
Berman MG, Kross E, Krpan KM, Askren MK, Burson A, Deldin PJ, Kaplan S, Sherdell L, Gotlib IH, Jonides J. Interacting with nature improves cognition and affect for individuals with depression. J Affect Disord. 2012;140:300–5. https://doi.org/10.1016/j.jad.2012.03.012.
Kuo FE, Faber Taylor A. A potential natural treatment for attention-deficit/hyperactivity disorder: evidence from a national study. Am J Public Health. 2004;94(9):1580–6. https://doi.org/10.2105/AJPH.94.9.1580.
Plutchik R. Emotions: a general psychoevolutionary theory. Approaches Emot. 1984:197–219. https://doi.org/10.1016/b978-0-12-558701-3.50007-7.
Segerstrom SC, Miller GE. Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry. Psychol Bull. 2004;130:601. https://doi.org/10.1037/0033-2909.130.4.601.
Cacioppo J, Berntson G, Malarkey W, Kiecolt-Glaser J, Sheridan J, Poehlmann K, et al. Autonomic, neuroendocrine, and immune responses to psychological stress: the reactivity hypothesisa. Ann N Y Acad Sci. 1998;840:664–73. https://doi.org/10.1111/j.1749-6632.1998.tb09605.x.
Hawkley L, Cacioppo J. Stress and the aging immune system. Brain Behav Immun. 2004;18:114–9. https://doi.org/10.1016/j.bbi.2003.09.005.
Uchino B, Smith T, Holt-Lunstad J, Campo R, Reblin M. Stress and illness. In: Cacioppo J, Tassinary L, Berntson G, editors. Handbook of psychophysiology. Cambridge, UK: Cambridge University Press; 2017. https://doi.org/10.1017/cbo9780511546396.026.
Ulrich-Lai Y, Herman J. Neural regulation of endocrine and autonomic stress responses. Nat Rev Neurosci. 2009;10:397–409. https://doi.org/10.1038/nrn2647.
McMahan EA, Estes D. The effect of contact with natural environments on positive and negative affect: a meta-analysis. J Posit Psychol. 2015;10:507–19. https://doi.org/10.1080/17439760.2014.994224.
Kotera Y, Richardson M, Sheffield D. Effects of Shinrin-yoku (forest bathing) and nature therapy on mental health: a systematic review and meta-analysis. Int J Ment Health Addict. 2022;20:337–61. https://doi.org/10.1007/s11469-020-00363-4.
Bratman G, Hamilton P, Daily G. The impacts of nature experience on human cognitive function and mental health. Ann N Y Acad Sci. 2012;1249:118–36. https://doi.org/10.1111/j.1749-6632.2011.06400.x.
Ideno Y, Hayashi K, Abe Y, Ueda K, Iso H, Noda M, et al. Blood pressure-lowering effect of Shinrin-yoku (forest bathing): a systematic review and meta-analysis. BMC Complement Altern Med. 2017;17:1–12. https://doi.org/10.1186/s12906-017-1912-z.
Ulrich R. Natural versus urban scenes: some psychophysiological effects. Environ Behav. 1981;13:523–56. https://doi.org/10.1177/0013916581135001.
Park BJ, Tsunetsugu Y, Kasetani T, Kagawa T, Miyazaki Y. The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan. Environ Health Prev Med. 2010;15:18–26. https://doi.org/10.1007/s12199-009-0086-9.
Gameiro G, Minguini I, Alves T. The role of stress and life events in the onset of depression in the elderly. Rev Med. 2014;93:31–40. https://doi.org/10.11606/issn.1679-9836.v93i1p31-40.
Hammen C, Hazel N, Brennan P, Najman J. Intergenerational transmission and continuity of stress and depression: depressed women and their offspring in 20 years of follow up. Psychol Med. 2012;42:931–42. https://doi.org/10.1017/S0033291711001978.
Esch T, Stefano G, Fricchione G, Benson H. The role of stress in neurodegenerative diseases and mental disorders. Neuro Endocrinol Lett. 2002;23:199–208.
Hammen C. Stress and depression: old questions, new approaches. Curr Opin Psychol. 2015;4:80–5. https://doi.org/10.1016/j.copsyc.2014.12.024.
Hussenoeder F, Conrad I, Pabst A, Luppa M, Stein J, Engel C, et al. Different areas of chronic stress and their associations with depression. Int J Environ Res Public Health. 2022;19:8773. https://doi.org/10.3390/ijerph19148773.
World Health Organization. The World Health Report 2001: mental health: new understanding. Geneva WHO: New Hope; 2001.
Bergenheim A, Ahlborg G Jr, Bernhardsson S. Nature-based rehabilitation for patients with long-standing stress-related mental disorders: a qualitative evidence synthesis of patients’ experiences. Int J Environ Res Public Health. 2021;18:6897. https://doi.org/10.3390/ijerph18136897.
Grahn P, Palsdottir A, Ottosson J, Jonsdottir I. Longer nature-based rehabilitation may contribute to a faster return to work in patients with reactions to severe stress and/or depression. Int J Environ Res Public Health. 2017;14:1310. https://doi.org/10.3390/ijerph14111310.
Sahlin E, Ahlborg G Jr, Tenenbaum A, Grahn P. Using nature-based rehabilitation to restart a stalled process of rehabilitation in individuals with stress-related mental illness. Int J Environ Res Public Health. 2015;12:1928–51. https://doi.org/10.3390/ijerph120201928.
Lehrer P, Kaur K, Sharma A, Shah K, Huseby R, Bhavsar J, Zhang Y. Heart rate variability biofeedback improves emotional and physical health and performance: a systematic review and meta analysis. Appl Psychophysiol Biofeedback. 2020;45:109–29. https://doi.org/10.1007/s10484-020-09466-z.
Beckers F, Ramaekers D, Speijer G, Ector H, Vanhaecke J, Verheyden B, . . . Aubert AE. Different evolutions in heart rate variability after heart transplantation: 10-year follow-up. Transplantation. 2004:78:1523-1531. https://doi.org/10.1097/01.tp.0000141093.04132.41
Eckberg DL. Topical review: the human respiratory gate. J Physiol. 2003;548:339–52. https://doi.org/10.1113/jphysiol.2002.037192.
Jarczok M, Koenig J, Wittling A, Fischer J, Thayer J. First evaluation of an index of low vagally-mediated heart rate variability as a marker of health risks in human adults: proof of concept. J Clin Med. 2019;8:1940. https://doi.org/10.3390/jcm8111940.
Forte G, Favieri F, Casagrande M. Heart rate variability and cognitive function: a systematic review. Front Neurosci. 2019;13:710. https://doi.org/10.3389/fnins.2019.00710.
Nashiro K, Yoo HJ, Cho C, Min J, Feng T, Nasseri P, et al. Effects of a randomised trial of 5-week heart rate variability biofeedback intervention on cognitive function: possible benefits for inhibitory control. Appl Psychophysiol Biofeedback. 2022:1–14. https://doi.org/10.1007/s10484-022-09563-1.
Nashiro K, Min J, Yoo HJ, Cho C, Bachman SL, Dutt S, et al. Enhancing the brain’s emotion regulation capacity with a randomised trial of a 5-week heart rate variability biofeedback intervention. MedRxiv. 2021; https://doi.org/10.1007/s10484-022-09563-1.
Yoo H, Nashiro K, Min J, Cho C, Bachman S, Nasseri P, et al. Heart rate variability (HRV) changes and cortical volume changes in a randomized trial of five weeks of daily HRV biofeedback in younger and older adults. Int J of Psychophysiol. 2022;181:50–63. https://doi.org/10.1016/j.ijpsycho.2022.08.006.
Kemp AH, Quintana DS, Gray MA, Felmingham KL, Brown K, Gatt JM. Impact of depression and antidepressant treatment on heart rate variability: a review and meta-analysis. Biol Psychiatry. 2010;67:1067–74. https://doi.org/10.1016/j.biopsych.2009.12.012.
Koch C, Wilhelm M, Salzmann S, Rief W, Euteneuer F. A meta-analysis of heart rate variability in major depression. Psychol Med. 2019;49:1948–57. https://doi.org/10.1017/S0033291719001351.
Pizzoli S, Marzorati C, Gatti D, Monzani D, Mazzocco K, Pravettoni G. A meta-analysis on heart rate variability biofeedback and depressive symptoms. Sci Rep. 2021;11:6650. https://doi.org/10.1038/s41598-021-86149-7.
Blase K, Vermetten E, Lehrer P, Gevirtz R. Neurophysiological approach by self-control of your stress-related autonomic nervous system with depression, stress and anxiety patients. Int J Environ Res Public Health. 2021;18(7):3329. https://doi.org/10.3390/ijerph18073329.
•• Cheng X, Liu J, Liu H, Lu S. A systematic review of evidence of additional health benefits from forest exposure. Landsc Urban Plan. 2012;212:104123. https://doi.org/10.1016/j.landurbplan.2021.104123. Meta-analysis of several health benefits in nature, including vmHRV
Scott EE, LoTemplio SB, McDonnell AS, McNay GD, Greenberg K, McKinney T, et al. The autonomic nervous system in its natural environment: immersion in nature is associated with changes in heart rate and heart rate variability. Psychophysiology. 2021;58(4):e13698.
Meredith G, Rakow D, Eldermire E, Madsen C, Shelley S, Sachs N. Minimum time dose in nature to positively impact the mental health of college-aged students, and how to measure it: a scoping review. Front Psychol. 2019;10:2942. https://doi.org/10.3389/fpsyg.2019.02942.
Sterne JAC, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, Cates CJ, Cheng H-Y, Corbett MS, Eldridge SM, Hernán MA, Hopewell S, Hróbjartsson A, Junqueira DR, Jüni P, Kirkham JJ, Lasserson T, Li T, McAleenan A, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ. 2019;366:l4898. https://doi.org/10.1136/bmj.l4898.
Sterne JAC, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M, Henry D, Altman DG, Ansari MT, Boutron I, Carpenter JR, Chan AW, Churchill R, Deeks JJ, Hróbjartsson A, Kirkham J, Jüni P, Loke YK, Pigott TD, et al. ROBINS-I: a tool for assessing risk of bias in non-randomized studies of interventions. BMJ. 2016;355:i4919. https://doi.org/10.1136/bmj.i4919.
Shaffer F, Ginsberg JP. An overview of heart rate variability metrics and norms. Front Public Health. 2017;5:258. https://doi.org/10.3389/fpubh.2017.00258.
Smith TW, Deits-Lebehn C, Williams PG, Baucom BR, Uchino BN. Toward a social psychophysiology of vagally mediated heart rate variability: concepts and methods in self-regulation, emotion, and interpersonal processes. Soc Personal Psychol Compass. 2020;14:e12516. https://doi.org/10.1111/spc3.12516.
Billman GE. The LF/HF ratio does not accurately measure cardiac sympatho-vagal balance. Front Physiol. 2013;4:26. https://doi.org/10.3389/fphys.2013.00026.
Thal L. Attention-deficit hyperactivity disorder and exposure to nature in college students. University of Missouri-Columbia, Thesis; 2014.
Gidlow C, Jones M, Hurst G, Masterson D, Clark-Carter D, Tarvainen M, et al. Where to put your best foot forward: psycho-physiological responses to walking in natural and urban environments. J Environ Psychol. 2016;45:22–9. https://doi.org/10.1016/j.jenvp.2015.11.003.
Rogerson M, Gladwell VF, Gallagher DJ, Barton JL. Influences of green outdoors versus indoors environmental settings on psychological and social outcomes of controlled exercise. Int J Environ Res Public Health. 2016;13:363. https://doi.org/10.3390/ijerph13040363.
de Brito J, Pope Z, Mitchell N, Schneider I, Larson J, Horton T, Pereira M. Changes in psychological and cognitive outcomes after green versus suburban walking: a pilot crossover study. Int J Environ Res Public Health. 2019;16:2894. https://doi.org/10.3390/ijerph16162894.
Bodin M, Hartig T. Does the outdoor environment matter for psychological restoration gained through running? Psychol Sport Exerc. 2003;4:141–53. https://doi.org/10.1016/S1469-0292(01)00038-3.
Kim W, Lim SK, Chung EJ, Woo JM. The effect of cognitive behavior therapy-based psychotherapy applied in a forest environment on physiological changes and remission of major depressive disorder. Psychiatry Investig. 2009;6:245. https://doi.org/10.4306/pi.2009.6.4.245.
Lee J, Tsunetsugu Y, Takayama N, Park BJ, Li Q, Song C, et al. Influence of forest therapy on cardiovascular relaxation in young adults. eCAM. 2014:1–7. https://doi.org/10.1155/2014/834360.
Bang K, Lee I, Kim S, Lim CS, Joh H, Park B, Song M. The effects of a campus forest-walking program on undergraduate and graduate students’ physical and psychological health. Int J Environ Res Public Health. 2017;14:728. https://doi.org/10.3390/ijerph14070728.
Yu C, Lin C, Tsai M, Tsai Y, Chen C. Effects of short forest bathing program on autonomic nervous system activity and mood states in middle-aged and elderly individuals. Int J Environ Res Public Health. 2017;14:897. https://doi.org/10.3390/ijerph14080897.
Brown D, Barton J, Pretty J, Gladwell V. Walks4Work: assessing the role of the natural environment in a workplace physical activity intervention. Scand J Work Environ Health. 2014;40:390–9. https://doi.org/10.5271/sjweh.3421.
Furuyashiki A, Tabuchi K, Norikoshi K, Kobayashi T, Oriyama S. A comparative study of the physiological and psychological effects of forest bathing (Shinrin-yoku) on working age people with and without depressive tendencies. Environ Health Prev Med. 2019;24:1–11. https://doi.org/10.1186/s12199-019-0800-1.
Saadi D, Schnell I, Tirosh E, Basagaña X, Agay-Shay K. There’s no place like home? The psychological, physiological, and cognitive effects of short visits to outdoor urban environments compared to staying in the indoor home environment, a field experiment on women from two ethnic groups. Environ Res. 2020;187:109687. https://doi.org/10.1016/j.envres.2020.109687.
Riglin L, Leppert B, Dardani C, Thapar A, Rice F, O’Donovan M, et al. ADHD and depression: investigating a causal explanation. Psychol Med. 2021;51:1890–7. https://doi.org/10.1017/s0033291720000665.
American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed; 2013. https://doi.org/10.1176/appi.books.9780890425596.
Ostrander R, Herman KC. Potential cognitive, parenting, and developmental mediators of the relationship between ADHD and depression. J Consult Clin Psychol. 2006;74:89. https://doi.org/10.1037/0022-006x.74.1.89.
Li H, Browning MH, Rigolon A, Larson LR, Taff D, Labib SM, et al. Beyond “bluespace” and “greenspace”: a narrative review of possible health benefits from exposure to other natural landscapes. Sci Total Environ. 2022;856:159292. https://doi.org/10.1016/j.scitotenv.2022.159292.
Frumkin H, Bratman GN, Breslow SJ, Cochran B, Kahn PH Jr, Lawler JJ, et al. Nature contact and human health: a research agenda. Environ Health Perspect. 2017;125:075001. https://doi.org/10.1289/EHP1663.
Erickson KI, Hillman CH, Kramer AF. Physical activity, brain, and cognition. Curr Opin Behav Sci. 2015;4:27–32.
•• Gallegos-Riofrío CA, Arab H, Carrasco-Torrontegui A, Gould RK. Chronic deficiency of diversity and pluralism in research on nature’s mental health effects: a planetary health problem. Curr Res Environ Sustain. 2022;4:–100148. https://doi.org/10.1016/j.crsust.2022.100148. Important and comprehensive review of the lack of diversity in nature and mental health study samples
Moak JP, Goldstein DS, Eldadah BA, Saleem A, Holmes C, Pechnik S, Sharabi Y. Supine low-frequency power of heart rate variability reflects baroreflex function, not cardiac sympathetic innervation. Heart Rhythm. 2007;4:1523–9. https://doi.org/10.1016/j.hrthm.2007.07.019.
Beute F, de Kort YA. Salutogenic effects of the environment: review of health protective effects of nature and daylight. Appl Psychol Health Well Being. 2007;6:67–95. https://doi.org/10.1111/aphw.12019.
While there was no funding to support the research, Dr. Bettmann received funding from Nature Human Health Utah to disseminate these and other findings at national conferences.
Conflict of Interest
The authors declare no competing interests.
Human and Animal Rights and Informed Consent
This study was approved by the University of Utah Institutional Review Board.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
LoTemplio, S., Bettmann, J.E., Scott, E. et al. Do Mental Health Changes in Nature Co-occur with Changes in Heartrate Variability and Executive Functioning? A Systematic Review. Curr Envir Health Rpt 10, 278–290 (2023). https://doi.org/10.1007/s40572-023-00407-6