Virtual reality video games can truly come to life with scents designed to match the action, according to a new study.
In experiments, volunteers played the virtual reality (VR) game Resident Evil 7 Biohazard, with and without smells that supplemented parts of the game.
Survival horror game scenes feature intense smelling objects such as rotting food, smoke, and a rotting head.
The researchers found that adding scents significantly increased the sense of being present in the game environment.
Screenshot from Resident Evil 7 Biohazard, a virtual reality game featuring intense smelling objects such as rotting food, smoke, and a rotting head
In Resident Evil 7 Biohazard, the player controls Ethan Winters from a first-person perspective as he searches an abandoned estate for his missing wife.
The new study was conducted by researchers from the Australian government agency CSIRO and the University of Technology Sydney.
“Virtual reality (VR) headsets provide immersive audio-visual experiences for users, but typically fail to deliver olfactory cues that can provide additional information about our real-world surroundings,” they state in their paper.
“Overall, the results indicate that adding odors to a VR environment had a significant effect on the psychological and physiological experience, showing that adding odors improved the VR environment.”
For the study, the researchers recruited 22 subjects who explored the same VR environment from Resident Evil 7.
A total of 13 of the participants had previous experience with virtual reality and only three participants had no video game experience. Only one participant had previously played Resident Evil 7.
As they played, the game was supplemented with odors generated by an olfactometer, which delivered volatile odors through a flexible plastic tube secured under a participant’s nose.
Zone 1: participant briefing and post-gameplay questionnaires, Zone 2: the gameplay zone, Zone 3: the olfactometer, and Zone 4: the monitoring/supervision zone.
One of the volatiles was cis-3-hexene-1-ol, an oily liquid that smells of freshly cut grass, to enhance the feeling of being in a forest.
Another was dimethyl trisulfide, a breakdown product of bacterial decay, including the early stages of human decay.
Participants walked through the same VR environment twice, with or without the introduction of olfactory stimuli.
Directly after each gameplay, participants completed a questionnaire to determine their “sense of presence” (feeling of being in a particular place or time period) from the overall gameplay, as well as their sense of immersion in each of the scenes.
In addition, physiological measurements – heart rate, body temperature, and skin electrodermal activity – were collected from half of the participants for each game. “Electrodermal activity” refers to changes in skin resistance to a small electric current based on sweat gland activity.
The results showed that the addition of odors significantly increased participants’ sense of spatial presence in the VR environment compared to VR without odor.
Participants also rated the realism of the VR experience with higher odor versus no odor; however, the smell did not lead to a change in the emotional state of the participants (arousal, pleasure and dominance).
The survival horror game, which supports the PlayStation VR headset, is the first mainline Resident Evil game to use a first-person view
Additionally, participants’ physiological responses were affected by the addition of odor.
The team says scents provide an opportunity to “create a more immersive experience to increase a person’s presence in a VR environment.”
“In addition to games, the results have broader applications for virtual training environments and virtual reality exposure therapy,” they write.
The study was published in the journal PLOS One.