Pain intensity and unpleasantness are decreased after a virtual walk through green space

An experimental study in Poland found that the perceived intensity and unpleasantness of experimentally induced pain decreased after a four-minute walk through a green environment (a virtual park rich in vegetation). The pain was induced by a thermode attached to the inner side of participants’ forearms and heated to as much as 50.5 °C. The paper was published in Scientific Reports.

Green spaces are areas of natural vegetation, such as parks, gardens, forests, or urban green belts, that are accessible to people. They offer opportunities for recreation, relaxation, and contact with nature in both urban and rural settings.

Psychologically, green spaces tend to reduce stress by lowering cortisol levels and calming the nervous system. They are linked to improved mood, greater happiness, and lower rates of depression and anxiety. Being surrounded by greenery can also restore attention and mental energy, a phenomenon described by the attention restoration theory. Even brief exposure to trees or grass can enhance concentration and reduce mental fatigue. Neighborhoods with abundant greenery often show lower crime rates and higher perceived safety, partly due to stronger community cohesion.

Study author Anna Mucha and her colleagues set out to examine how experiencing a virtual reality (VR) green space affects people’s perception of pain compared to an urban VR environment. Specifically, they wanted to see whether immersion in a VR green space would reduce the perception of experimentally induced thermal pain in healthy adults more than an urban VR scenario.

Participants were 81 healthy adults, with an average age of 23 years; 61% were women. They were randomly divided into two groups. One group took a four-minute walk through a VR green space using VR goggles, while the other walked through an urban VR setting of the same duration using the same equipment.

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Before the VR walk, the researchers fitted participants with a 30 × 30 mm thermode, part of the TSA-II neurosensory analyzer. A thermode is a device that precisely delivers controlled heating or cooling to the skin. In this study, it was set to increase its temperature from 30 °C up to 50.5 °C. The researchers first tested each participant’s pain threshold and tolerance. The device started at 30 °C and increased by 1.5 °C per second, stopping at the maximum or when the participant chose to end the test.

The pain threshold was the lowest temperature at which participants reported feeling pain. Pain tolerance was the point at which they chose to stop the test because the sensation became unbearable. Participants used a handheld remote to stop the temperature increase, after which the thermode cooled quickly.

Participants also rated the intensity and unpleasantness of the pain. For this, the thermode was set to a temperature 0.5 °C below each participant’s tolerance level for up to 10 seconds. They rated pain intensity on an 11-point visual analogue scale and also assessed their positive and negative emotions. These ratings were completed before and after the assigned VR walk, with participants still wearing the goggles and immersed in the virtual environment during the second set of assessments.

The results indicated that pain intensity and unpleasantness decreased after the VR walk in the green environment. Pain tolerance thresholds remained similar before and after the walk in both the green and urban settings. Positive emotions increased, while negative emotions decreased after the green walk. No changes in emotional state were observed following the urban walk.

“These results indicate that contact with nature, even in the form of VR, can effectively relieve pain not only by reducing its intensity but also by reducing its unpleasantness,” the study authors concluded.

The study sheds light on the effects of exposure to green spaces on the perception of pain. However, it should be noted that this experiment was conducted in virtual reality and did not involve real exposure to nature, or real walking through nature.

The paper, “Effect of virtual walk in green or urban spaces on pain perception among healthy adults,” was authored by Anna Mucha, Anita Pollak, and Ewa Wojtyna.