Virtual Reality (VR) has become a key technology in our current digital society. Once merely featured in science fiction films, VR is now becoming increasingly popular in different domains of life like gaming, marketing, industrial training, and education.
However, despite its relatively recent rise to popularity, VR’s use in the medical sphere has a longer history. The first healthcare applications of VR started in the early ’90s due to the need of medical staff to visualize complex medical data, particularly during surgery and for surgery planning (Chinnock, 1994). During this initial period, other medical applications included surgical simulators for medical training, telepresence surgery, pain management, physical therapy and motor rehabilitation (Satava, 1995), and the treatment of mental health disorders (Botella et al., 2004).
As a result, after three decades of research, the use of VR as a therapeutic tool in the field of psychology has accumulated impressive scientific evidence on its utility for the assessment and treatment of a variety of psychological disorders and behavioral issues. Recent review and meta-analytic studies have shown that VR-based interventions can be an effective alternative to the most traditional cognitive-behavioral intervention tools for overcoming mental health disorders, mainly related to:
In the specialized literature the construct of presence is usually considered the principal mechanism by which VR is effective as a clinical intervention tool (Alsina-Jurnet & Gutiérrez-Maldonado, 2010). This term is related to the user’s illusion of being transported to a virtual environment, irrespective of her physical environment and without a relevant cognitive effort. One of the main consequences of this illusion is that the virtual scenario may evoke the same reactions, thoughts, and emotions as the experience in a real-world situation (Alsina Jurnet et al., 2011). Thus, for example, if an individual is exposed to peaceful, pleasant, non-arousing nature-based virtual scenarios, then they would experience feelings of relaxation, vitality, and restoration that are very similar to those experienced in physical natural environments (Mattila et al., 2020). The sense of presence in virtual environments helps to understand the restorative effects of VR, as well as its potential to promote a good emotional wellbeing in both clinical and non-clinical populations.
In a wider sense, the use of VR to promote relaxation, reduce stress, and restore work productivity is based on the Attention Restoration Theory (ART) (Kaplan, 2001). According to this theory, the tasks performed in our daily life require directed attention, where focusing on the task requires effort and cognitive resources. But those resources can be restored and improved by exposing us to situations that provide a psychological and emotional distance from our mental concerns (“being away” from our daily routine), combined with effortless, interest-driven attention (“fascination”), and supported by an environment of substantial scope (Anderson et al., 2017). Such experiences allow the mind to rest, thereby regaining its voluntary attention capacity, and relieving mental fatigue and stress (Ohly et al., 2016). According to this theory, the mechanisms that lead to mental restoration can be found in natural scenarios, while urban environments contribute to the depletion of directed attention (Kaplan, 1995). Urban environments contain a variety of stimuli (for ex.: lights, loud sounds, dynamic lights, etc.) that capture peoples’ attention while also requiring directed attention to overcome the stimuli (e.g., ignoring advertisements). As a result, urban scenarios are less restorative than natural environments as they draw the individual’s attention towards them as he or she attempts to overcome the stimuli (Berman et al., 2008).
The use of nature-based VR scenarios is also based on the Stress Recovery Theory (SRT) (Ulrich, 1983). SRT has its roots in evolutionary psychology and claims that because humans evolved during a long period in natural environments, people are psychologically and physiologically adapted to natural, as opposed to urban scenarios (Ulrich et al., 1991). According to this theory, nature-based environments aid in recovering from stress by inducing a positive affective state. The positive affective state is evoked because nature scenes comprise specific structural and visual properties (for ex.: complexity and depth) and a lack of perceived threat that cannot be found in urban scenarios (Ulrich, 1983). It is interesting to mention that in line with ART and SRT, several studies have shown that photographs (Brown et al., 2013; Gladwell et al., 2012), real locations (Miyazaki et al., 2014; Tsunetsugu et al., 2013) and VR scenarios of natural environments (Tanja-Dijkstra, et al., 2014; Schutte et al., 2017; Valtchanov and Ellard, 2010; Yu et al., 2018) have a more positive impact on individuals’ psychological wellbeing compared to photographs, real locations or VR scenarios of urban environments.
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Specifically in relation to nature-based VR, there is now scientific evidence that suggests that the exposure to immersive natural scenes is effective in reducing stress and promoting a positive mood in the general population. In particular, although more research is still needed, current studies suggest that the use of natural virtual scenarios like a tropical beach (Anderson et al., 2017; Blum et al., 2019), outdoor forest settings (Annerstedt et al., 2013; Browning et al., 2020; Chan et al., 2021; Rockstroh et al., 2020; Valtchanov & Ellard, 2010; Wang et al., 2019, Yu et al., 2018), underwater environments (Liszio et al., 2018), a river (Navarro Haro et al., 2017), a meadow (Schutte et al., 2017), a wilderness park (Villani & Riva, 2012) or a tropical island (Villani & Riva, 2007) support and promote relaxation, stress restoration and a positive mood. In addition, the use of natural VR scenarios has been shown to activate the parasympathetic system, which facilitates mood regulation and stress recovery (Valtchanov et al., 2010).
These studies summarize the benefits and effectiveness of nature exposure via virtual environments. Immersive technologies like VR can provide emotional wellbeing advantages. For example, during a work day when there is no access to highly restorative natural environments, or they can enable relaxation and stress recovery for people living in isolated confined environments. In general, the existing literature points towards the potential role of simulating nature in health and wellbeing promotion.
Going one step beyond the above mentioned studies, other researchers have integrated therapeutic narratives within virtual environments. Villani and Riva (2012) have found that a wilderness VR tropical environment combined with different relaxation exercises (based on autogenic training, progressive muscular relaxation and breathing techniques) supported by a relaxing narrative improved the users emotional wellbeing. In a similar way, Blum et al. (2019) have demonstrated that the use of a virtual beach that integrated slow breathing techniques (six cycles per minute) increased relaxation self-efficacy, reduced mind wandering, and helped the participants to focus on the present moment. Naylor et al. (2019) have also found that guided breathing exercises within nature VR scenarios can induce a positive effect on participant wellbeing.
Interestingly, other researchers have combined the exposure to nature virtual scenarios with the use of mindfulness techniques. This approach has been effective in enhancing state mindfulness and in inducing a positive affect by supporting the user’s focus of attention in the present moment within a tailored virtual setting (Seabrook et al. 2020). Finally, in a pioneering study conducted by Cebolla et al. (2019), it was found that compassion-based meditation combined with embodied VR can increase the frequency of mindfulness relaxation compared to a control group of meditation without embodied VR.
In general, it is interesting to note that all the studies that combined the exposure to virtual nature with guided meditation or breathing techniques reported significant increases in relaxation and positive mood.
We live in a multi-sensory world, where our experiences are constructed by the stimulation of five senses. One of our dominant sensory systems is the sense of smell, which is directly linked to cognitive processes such as learning and memory (Choi & Han, 2015), as well as to our emotions (Motomura & Sakurai, 2001) and mood (Warrenburg, 2005). Although most of our daily emotions and memories are activated by smells, the majority of current VR applications only rely on audiovisual stimuli. Unfortunately, the sense of smell has been largely ignored by VR developers.
Essential oils offer an accessible and viable method of providing olfactory stimulation during exposure to nature-based VR scenarios (see this post for a review of the benefits of essential oils on mental health). In particular, Cheng et al. (2020) found that combining VR and essential oils reduces stress, and increases levels of happiness and life satisfaction in older adults. Oyama et al. (2000) observed that the use of essential oils during exposure to nature-based VR scenarios (a lake, a forest or a country town) is an effective method for reducing fatigue and emesis (vomiting) in cancer patients receiving chemotherapy in an outpatient clinic. In a similar way, Hedblom et al. (2019) have also found benefits in stress reduction when combining nature-based VR environments (a park and a forest) with essential oils.
Using a novel approach, Kaimal et al. (2020) found that the inclusion of an olfactory stimulus (a calming fragrance blend) during a VR art-making session reduced the negative affect of healthy adults. FInally, Schebela et al. (2019) observed that a multi-sensorial experience composed of VR and “nature”-based scents was associated with better stress recovery than a visual-only experience. In general, current studies suggest that multi-sensorial VR experiences which include essential oils are effective at improving the psychological wellbeing of clinical and non-clinical populations.
To conclude, it is relevant to mention that the inclusion of olfactory stimuli in virtual environments increases the sense of presence (the sense of being inside the virtual scenarios) (Munyan et al., 2016; Narciso et al., 2020) and the sense of reality (Baus et al., 2019). As a result, these types of multimodal experiences will be capable of inducing more intense emotions (Alsina-Jurnet et al., 2011) such as deeper states of calm and relaxation.
At Relax VR, we combine exposure to virtual natural landscapes, therapeutic narratives (based on guided meditations), binaural beats and organic essential oils, with the aim of improving the quality of life and the emotional well-being of its users. Recent studies have shown the efficacy of Relax VR to:
These findings suggest that VR is an effective and affordable tool to reduce negative emotions and promote relaxation in the general population. It also gives new scientific evidence that supports the restorative effects of experiencing natural virtual environments.
Regarding the efficacy of specific components of Relax VR, a pioneering controlled study conducted by Krainbuhl et al. (2022) explored the effects of including a therapeutic narrative within a nature-based scenario, with the aim of enhancing the analgesic (pain-relieving) effects of VR. The results of the study demonstrated that the inclusion of a therapeutic narrative in the VR-world significantly improved pain tolerance and increased the levels of enjoyment during a painful procedure. This study represents a significant advancement in understanding the specific effects of therapeutic narratives in virtual environments.
In another pioneering controlled study based on Relax VR (Alsina-Jurnet et al., in press), the researchers compared the efficacy of VR with a traditional audio technique in patients with severe mental health disorders. Participants were assigned to either an experimental group that listened to a therapeutic narrative or an experimental group that experienced the therapeutic narrative within a nature-based virtual world. All participants completed the procedure from their own houses once per day during a two-week period. The results showed that the combination of VR and the therapeutic narrative resulted in reduced dropouts, improved program adherence, increased patient satisfaction, and reduced negative emotions to a greater extent.
In general, those studies provide evidence about the efficacy of combining two specific components of Relax VR: VR nature-scenes and the therapeutic narrative.
Adabla, S., Nabors, L., & Hamblin, K. (2021). A Scoping Review of Virtual Reality Interventions for Youth with Attention-Deficit/Hyperactivity Disorder. Advances in Neurodevelopmental Disorders, 5, 304-315. DOI: https://doi.org/10.1007/s41252-021-00207-9
Alsina-Jurnet, I. Gutiérrez-Maldonado, J. & Rangel-Gómez, M.V. (2011) The role of presence in the level of anxiety experienced in clinical virtual environments. Computers in Human Behavior, 27, 504-512. DOI: https://doi.org/10.1016/j.chb.2010.09.018
Alsina-Jurnet, I. & Gutiérrez-Maldonado, J. (2010).Influence of personality and individual abilities on the sense of presence experienced in anxiety triggering virtual environments. International Journal of Human-Computer Studies, 68, 788-801. DOI: https://doi.org/10.1016/j.ijhcs.2010.07.001
Alsina-Jurnet, I. Gutiérrez-Maldonado, J. & Rangel-Gómez, M.V. (2011) The role of presence in the level of anxiety experienced in clinical virtual environments. Computers in Human Behavior, 27, 504-512. DOI: https://doi.org/10.1016/j.chb.2010.09.018
Anderson, A.P., Mayer, M.D., Fellows, A.M., Cowan, D.R., Hegel, M.T., & Buckey, J.C. (2017). Relaxation with immersive natural scenes presented using virtual reality. Aerospace Medicine and Human Performance, 88(6), 520-526. DOI: https://doi.org/10.3357/AMHP.4747.2017
Annerstedt, M., Jönsson, P., Wallergård, M., Johansson, G., Karlson, B., Grahn, P., Hansen, A.M., & Währborg, P. (2013). Inducing physiological stress recovery with sounds of nature in a virtual reality forest – results from a pilot study. Physiology and Behavior, 118, 240–250. DOI: https://doi.org/10.1016/j.physbeh.2013.05.023
Baus, O., Bouchard, S., & Nolet, K. (2020). Exposure to a pleasant odour may increase the sense of reality, but not the sense of presence or realism. Behaviour & Information Technology, 38(12), 1369-1378. DOI: https://doi.org/10.1080/0144929X.2019.1590458
Berman, M.G., Jonides, J., & Kaplan, S. (2008) The cognitive benefits of interacting with nature. Psychological Science, 19(12), 1207–1212. DOI: https://doi.org/10.1111/j.1467-9280.2008.02225.x
Blum, J., Rockstroh, C., & Göritz, A.S. (2019). Heart rate variability biofeedback based on slow-paced breathing with immersive virtual reality nature scenery. Frontiers in Psychology, 10:2171. DOI: https://doi.org/10.3389/fpsyg.2019.02172
Botella, C., Quero, S., Baños, R.M., Perpiñá, C., García Palacios, A., & Riva, G. (2004). Virtual reality and psychotherapy. Studies in Health Technology and Informatics, 99, 37-54. Available at: https://pubmed.ncbi.nlm.nih.gov/15295145/
Brown, D.K., Barton, J.L., & Gladwell, V.F. (2013). Viewing nature scenes positively affects recovery of autonomic function following acute-mental stress. Environmental Science & Technology, 47(11), 5562-5569. DOI: https://doi.org/10.1021/es305019p
Browning, M.H.E.M., Mimnaugh, K.J., van Riper, C.J., Laurent, H.K., LaValle, S.M. (2020) Can simulated nature support mental health? Comparing short, single-doses of 360-degree nature videos in virtual reality with the outdoors. Frontiers in Psychology, 10:2667. DOI: https://doi.org/10.3389/fpsyg.2019.02667
Callistus Nwosu, A., Mills, M., Roughneen, S., Stanley, S., Chapman, L., & Mason, S.R. (2021). Virtual reality in specialist palliative care: a feasibility study to enable clinical practice adoption. BMJ Supportive & Palliative Care, bmjspcare-2020-002327. DOI: https://doi.org/10.1136/bmjspcare-2020-002327
Carl, E., Stein, A. T., Levihn-Coon, A., Pogue, J. R., Rothbaum, B., Emmelkamp, P., Asmundson, G.J.G., Carlbring, P., & Powers, M.B. (2019). Virtual reality exposure therapy for anxiety and related disorders: A meta-analysis of randomized controlled trials. Journal of Anxiety Disorders, 61, 27–36. DOI: https://doi.org/10.1016/j.janxdis.2018.08.003
Cebolla, A., Herrero, R., Ventura, S., Miragall, M., Bellosta-Batalla, M., Llorens, R., & Baños, R.M. (2019). Putting oneself in the body of others: a pilot study on the efficacy of an embodied virtual reality system to generate self-compassion. Frontiers in Psychology, 10:1521. DOI: https://doi.org/10.3389/fpsyg.2019.01521
Chan, S.H.M., Qiu, L., Esposito, G., Mai, K.P., Tam, K-P., & Ciu, J. (2021). Nature in virtual reality improves mood and reduces stress: evidence from young adults and senior citizens. Virtual Reality, 1-16. DOI: https://doi.org/10.1007/s10055-021-00604-4
Cheng, V. Y-W., Huang, C-M., Liao, J-Y., Hsu, H-P., Wang, S-W., Huang, S-F., & Guo, J-L. (2020). Combination of 3-Dimensional Virtual Reality and Hands-On Aromatherapy in Improving Institutionalized Older Adults' Psychological Health: Quasi-Experimental Study. Journal of Medical Internet Research, 22(7):e17096. DOI: https://doi.org/10.2196/17096
Chinnock, C. (1994). Virtual reality in surgery and medicine. Hospital technology series,13 (18), 1-48. Available at: https://pubmed.ncbi.nlm.nih.gov/10172193/
Choi, N-E., & Han, J.H. (2015). How Flavor Works. The Science of Taste and Aroma. Chichester: John Wiley & Sons. Available at: https://www.wiley.com/en-ie/How+Flavor+Works:+The+Science+of+Taste+and+Aroma-p-9781118865477
Clus, D., Larsen, M.E., Lemey, C., & Berrouiguet, S. (2018). The Use of Virtual Reality in Patients with Eating Disorders: Systematic Review. Journal of Medical Internet Research, 20(4): e157. DOI: https://doi.org/10.2196/jmir.7898
Deng, W., Hu, D., Xu, S., Liu, X., Zhao, J., Chen, Q., Liu, J., Zhang, Z., Jiang, W., Ma, L., Hong, X., Cheng, S., Liu, B., & Li, X. (2019). The efficacy of virtual reality exposure therapy for PTSD symptoms: A systematic review and meta-analysis. Journal of Affective Disorders, 257:698-709. DOI: https://doi.org/10.1016/j.jad.2019.07.086
Eshuis, L.V., van Gelderen, M.J., van Zuiden, M., Nijdam, M.J., Vermetten, E., Olff, M., & Bakker, A. (2020). Efficacy of immersive PTSD treatments: A systematic review of virtual and augmented reality exposure therapy and a meta-analysis of virtual reality exposure therapy. Journal of Psychiatric Research, 143:516-527. DOI: https://doi.org/10.1016/j.jpsychires.2020.11.030
Ferrer-Garcia, M., Gutiérrez-Maldonado, J., & Riva, G. (2013). Virtual reality based treatments in eating disorders and obesity: A review. Journal of Contemporary Psychotherapy: On the Cutting Edge of Modern Developments in Psychotherapy, 43(4), 207–221. DOI: https://doi.org/10.1007/s10879-013-9240-1
Gil-Solanas, E. (2017). Efectivitat de la realitat virtual per a la inducció de relaxació (Treball de Fi de Màster no publicat). Universitat de Vic. Available at: http://dspace.uvic.cat/xmlui/handle/10854/5232
Gladwell, V.F., Brown, D.K., Barton, J.L., Tarvainen, M.P., Kuoppa, P., Pretty, J., Suddaby, J.M., & Sandercock, G.R.H. (2012). The effects of views of nature on autonomic control. European Journal of Applied Physiology, 112(9), 3379-3386. DOI: https://doi.org/10.1007/s00421-012-2318-8
Goharinejad, S., Goharinejad, S., Hajesmaeel-Gohari, S., & Bahaadinbeigy, K. (2022). The usefulness of virtual, augmented, and mixed reality technologies in the diagnosis and treatment of attention deficit hyperactivity disorder in children: an overview of relevant studies. BMC Psychiatry, 22(1):4. DOI: https://doi.org/10.1186/s12888-021-03632-1
Hedblom, M., Gunnarsson, B., Iravani, B., Knez, I., Schaefer, M., Thorsson, P., & Lundström, J.N. (2019). Reduction of physiological stress by urban green space in a multisensory virtual experiment. Scientific Reports, 9, 10113. DOI: https://doi.org/10.1038/s41598-019-46099-7
Ju In Chan, J., Teng Yeam, C., Min Kee, H., Wen Tan, C., Sultana, R., Tiong Heng Sia, A., & Leong Sng, B. (2020). The use of pre-operative virtual reality to reduce anxiety in women undergoing gynecological surgeries: a prospective cohort study. BMC Anesthesiology, 20(1):261. DOI: https://doi.org/10.1186/s12871-020-01177-6
Kaplan, S. (2001). Meditation, restoration, and the management of mental fatigue. Environment and Behavior, 33, 480-506. DOI: https://doi.org/10.1177/00139160121973106
Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal of Environmental Psychology, 15(3), 169-182. DOI: https://doi.org/10.1016/0272-4944(95)90001-2
Krainbuhl, W.C., Moroni, V.M., Legeren, A.L., Alsina-Jurnet, I., & Bueno, A.M. (2022). Acute Pain Management in Virtual Environments: The Effect of a Therapeutic Narrative. Neuropsicología Latinoamericana, 14(2), 21–31. Available at: https://www.neuropsicolatina.org/index.php/Neuropsicologia_Latinoamericana/article/view/772
Krijn, M., Emmelkamp, P.M.G., Olafsson, R.P. & Biemond, R. (2004). Virtual reality exposure therapy of anxiety disorders: A review. Clinical Psychology Review, 24, 259,281. DOI: https://doi.org/10.1016/j.cpr.2004.04.001
Liszio, S., Graf, L., i Masuch, M. (2018). The relaxing effect of virtual nature: immersive technology provides relief in acute stress situations. Annual Review of CyberTherapy and Telemedicine, 16, 87-93. Available at: https://interactivemediainstitute.com/wordpress/wp-content/uploads/2019/04/ARCTT-16.pdf
Maciołek, J., Wąsek, W:, Kamiński, B., Piotrowicz, K., & Krzesińsk, P. (2020). The impact of mobile virtual reality-enhanced relaxation training on anxiety levels in patients undergoing cardiac rehabilitation. Kardiologia Polska, 78(10):1032-1034. DOI: https://doi.org/10.33963/KP.15528
Mattila, O., Korhonen, A., Pöyry. E., Hauru, K., Holopainen, J., & Parvinen, P. (2020). Restoration in a virtual reality forest environment. Computers in Human Behavior, 107, 106295. DOI: https://doi.org/10.1016/j.chb.2020.106295
Meyerbröker, K., & Emmelkamp, P. (2010). Virtual reality exposure therapy in anxiety disorders: a systematic review of process-and-outcome studies. Depression and Anxiety, 27(10), 933-944. DOI: https://doi.org/10.1002/da.20734
Miyazaki, Y., Ikei, H., & Song, C. (2014). Forest medicine research in Japan. Japanese Journal of Hygiene, 69(2), 122-135. DOI: https://doi.org/10.1265/jjh.69.122
Morina, N., Ijntema, H., Meyerbröker, K., & Emmelkamp, P. (2015). Can virtual reality exposure therapy gains be generalized to real-life? A meta-analysis of studies applying behavioral assessments. Behaviour Research and Therapy, 74, 18-24. DOI: https://doi.org/10.1016/j.brat.2015.08.010
Motomura, N. & Sakurai, A. (2001). Reduction of mental stress with lavender odorant. Perceptual and Motor Skills, 93(3), 713-718. DOI: https://doi.org/10.2466/pms.2001.93.3.713
Munyan, B.G. III, Neer, S.M., Beidel, D.C., & Jentsch, F. (2016). Olfactory Stimuli Increase Presence in Virtual Environments. PLoS ONE 11(6): e0157568. DOI: https://doi.org/10.1371/journal.pone.0157568
Narciso, D., Melo, M., Vasconcelos-Raposo, J., & Bessa, M. (2020). The Impact of Olfactory andWind Stimuli on 360 Videos Using Head-mounted Displays. ACM Transactions on Applied Perception, 17(1), 1-13. DOI: https://doi.org/10.1145/3380903
Naylor, M., Morrison, B., Ridout, B., & Campbell, A. (2019). Augmented experiences: investigating the feasibility of virtual reality as part of a workplace wellbeing intervention. Interacting with Computers, 31(5), 507-523. DOI: https://doi.org/10.1093/iwc/iwz033
Navarro-Haro, M.V., López-del-Hoyo, Y., Campos, D., Linehan, M.M., Hoffman, H.G., García-Palacios, A., Modrego-Alarcón, M., Borao, L., & García-Campayo, J. (2017). Meditation experts try virtual reality mindfulness: a pilot study evaluation of the feasibility and acceptability of virtual reality to facilitate mindfulness practice in people attending a mindfulness conference. PLoS ONE 12(11):e0187777. DOI: https://doi.org/10.1371/journal.pone.0187777
Ohly, H., White, M. P., Wheeler, B. W., Bethel, A., Ukoumunne, O. C., Nikolaou, V., & Garside, R. (2016). Attention restoration theory: A systematic review of the attention restoration potential of exposure to natural environments. Journal of Toxicology and Environmental Health, 19, 305–343. DOI: https://doi.org/10.1080/10937404.2016.1196155
Ong, T.L., Ruppert, M.M., Akbar, M., Rashidi, P., Ozrazgat-Baslanti, T., Bihorac, A., & Suvajdzic, M. (2020). Improving the Intensive Care Patient Experience With Virtual Reality-A Feasibility Study. Critical Care Explorations, 2(6):e0122. DOI: https://doi.org/10.1097/CCE.0000000000000122
Opris, D., Pintea, S., García-Palacios, A., Botella, C., Szamosköki, S., & David, D. (2012). Virtual reality exposure therapy in anxiety disorders: a quantitative meta-analysis. Depression and Anxiety, 29(2), 85-93. DOI: https://doi.org/10.1002/da.20910
Oyama, H., Kaneda, M., Katsumata, N., Akechi, T., & Ohsuga, M. (2000). Using the Bedside Wellness System During Chemotherapy Decreases Fatigue and Emesis in Cancer Patients. Journal of Medical Systems, 24(3), 173-182. DOI: https://doi.org/10.1023/a:1005591626518
Parsons, T., & Rizzo, A. (2008). Affective outcomes of virtual reality exposure therapy for anxiety and specific phobias: a meta-analysis. Journal of Behavior Therapy and Experimental Psychiatry, 39(3), 250-261. DOI: https://doi.org/10.1016/j.jbtep.2007.07.007
Pericot-Valverde, I., Germeroth, L. J., & Tiffany, S. T. (2016). The use of virtual reality in the production of cue-specific craving for cigarettes: a meta-analysis. Nicotine and Tobacco Research, 18(5), 538–546. DOI: https://doi.org/10.1093/ntr/ntv216
Powers, M., & Emmelkamp, P. (2008). Virtual reality exposure therapy for anxiety disorders: a meta-analysis. Journal of Anxiety Disorders, 22(3), 561-569. DOI: https://doi.org/10.1016/j.janxdis.2007.04.006
Rockstroh, C., Blum, J., & Göritz, A.S. (2020). Combining VR and biofeedback: the effects on perceived restorativeness and presence. Journal of Media Psychology: Theories, Methods, and Applications, 32(4), 176–186. DOI: https://doi.org/10.1027/1864-1105/a000270
Romero-Ayuso, D., Toledano-González, A., Rodríguez-Martínez, M., Arroyo-Castillo, P., Triviño-Juárez, J.M., González, P., Ariza-Vega, P., González, A., & Segura-Fragoso, A. (2021). Effectiveness of Virtual Reality-Based Interventions for Children and Adolescents with ADHD: A Systematic Review and Meta-Analysis. Children, 8(2):70. DOI: https://doi.org/10.3390/children8020070
Satava, R.M. (1995). Medical applications of virtual reality. Journal of Medical Systems, 19, 275-380. Available at: https://link.springer.com/article/10.1007/BF02257178
Seabrook, E., Kelly, R., Foley, F., Theiler, S., Thomas, N., Wadley, G., & Nedeljkovic, M. (2020). Understanding how virtual reality can support mindfulness practice: mixed methods study. Journal of Medical Internet Research, 22(3):e16106. DOI: https://doi.org/10.2196/16106
Schebella, M.F., Weber, D., Schultz, L., & Weinstein, P. (2019). The Nature of Reality: Human Stress Recovery during Exposure to Biodiverse, Multisensory Virtual Environments. International Journal of Environmental Research and Public Health, 17(1), 56. DOI: https://doi.org/10.3390/ijerph17010056
Schutte, N.S., Bhullar, N., Stilinović, E.J. &, Richardson, K. (2017). The impact of virtual environments on restorativeness and affect. Ecopsychology, 9(1), 1–7. DOI: https://doi.org/10.1089/eco.2016.0042
Segawa, T., Baudry, T., Bourla, A., Blanc, J-V., Peretti, C-S., Mouchabac, S., & Ferrari, F. (2020). Virtual Reality (VR) in Assessment and Treatment of Addictive Disorders: A Systematic Review. Frontiers in Neuroscience, 13:1409. DOI: https://doi.org/10.3389/fnins.2019.01409
Tanja-Dijkstra, K., Pahl, S,, White, M.P., Auvray, M., Stone, R.J., Andrade, J., May, J., Mills, I. & Moles, D.R. (2014). The Soothing Sea: A Virtual Coastal Walk Can Reduce Experienced and Recollected Pain.Environment and Behavior, 50(6), 599-625. DOI: https://doi.org/10.1177/0013916517710077
Tsunetsugu, Y., Lee, J., Park, B.-J., Tyrväinen, L., Kagawa, T., & Miyazaki, Y. (2013). Physiological and psychological effects of viewing urban forest landscapes assessed by multiple measurements. Landscape and Urban Planning, 113, 90-93. DOI: https://doi.org/10.1016/j.landurbplan.2013.01.014
Turner, W.A., & Casey, L.M. (2014). Outcomes associated with virtual reality in psychological interventions: where are we now? Clinical Psychology Review, 34, 634-644. DOI: https://doi.org/10.1016/j.cpr.2014.10.003
Ulrich, R.S. (1983). Aesthetic and affective response to natural environment. In I. Altman, J.F. Wohlwill (Eds.), Behavior and the natural environment, Springer US (1983), pp. 85-125. DOI: https://doi.org/10.1007/978-1-4613-3539-9_4
Ulrich, R.S.. Simons, R.F., Losito, B.D., Fiorito, E., Miles, M. A., & Zelson, M. (1991). Stress recovery during exposure to natural and urban environments. Journal of Environmental Psychology, 11(3), 201–230. DOI: https://doi.org/10.1016/S0272-4944(05)80184-7
Valtchanov, D., Barton, K.R., & Ellard, C. (2010). Restorative effects of virtual nature settings. Cyberpsychology, Behavior and Social Networking, 13(5), 503-512. DOI: https://doi.org/10.1089/cyber.2009.0308
Valtchanov, D., & Ellard, C. (2010). Physiological and affective responses to immersion in virtual reality: Effects of nature and urban settings. Journal of Cybertherapy and Rehabilitation, 3(4), 359–374. Available at: https://www.researchgate.net/publication/260511298_Physiological_and_affective_responses_to_immersion_in_virtual_reality_Effects_of_nature_and_urban_settings
Villani, D., & Riva, G. (2012). Does interactive media enhance the management of stress? Suggestions from a controlled study. Cyberpsychology, Behavior and Social Networking, 15(1), 24-30. https://doi.org/10.1089/cyber.2011.0141
Villani, D., Riva, F., & Riva, G. (2007) New technologies for relaxation: the role of presence. International Journal of Stress Management, 14(3), 260–274. DOI: https://doi.org/10.1037/1072-5245.14.3.260
Wang, X., Shi, Y., Zhang, B., & Chiang, Y. (2019). The influence of forest resting environments on stress using virtual reality. International Journal of Environmental Research and Public Health, 16(18):3263. DOI: https://doi.org/10.3390/ijerph16183263
Warrenburg, S. (2005). Effects of fragrance on emotions: Moods and physiology. Chemical Senses, 30, Issue suppl_1, i248–i249. DOI: https://doi.org/10.1093/chemse/bjh208
Yu, C-P., Lee, H-Y, & Luo, X-Y. (2018). The effect of virtual reality forest and urban environments on physiological and psychological responses. Urban Forestry & Urban Greening, 35, 106-114. DOI: https://doi.org/10.1016/j.ufug.2018.08.013