가상현실을 이용한 게임들은 종종 멀미나 구역을 일으키기도 하는데, 흥미로운 연구가 있었습니다. 퍼듀대학교 연구진에 의하면 이런 불편감을 해소시킬만한 방법이 있다고 합니다.
이런 simulator sickness 증상이 나타나는 것은 시각적인 혼동(confusion)이 발생한 것을 뇌가 적절하게 해소하지 못했기 때문이라고 알려져 있습니다. 그래서 연구진들은 우리의 코가 사물을 볼때 일종의 기준(reference)을 제공한다는 점에 착안했습니다. 그래서 보이는 가상현실의 공간에 '가짜 코(fake nose)'를 함께 나타나도록 했습니다. 그리고 41명의 지원자를 모집하여 비디오 게임을 수행하고 가상의 롤러코스터를 타는 장면을 보여주었습니다. 그랬더니 가짜 코가 나타나는 화면을 보여준 쪽(실험군)에서 멀미가 나타나기까지 소요된 시간이 대조군(가짜코가 없는)에 비해 평균 94초가 더 걸렸다고 하네요.
아래는 퍼듀대학교에서 발표한 내용의 기사 전문입니다.
WEST LAFAYETTE, Ind.
– Virtual reality games often cause simulator sickness – inducing vertigo and sometimes nausea - but new research findings point to a potential strategy to ease the affliction.
Various physiological systems govern the onset of simulator sickness: a person's overall sense of touch and position, or the somatosensory system; liquid-filled tubes in the ear called the vestibular system; and the oculumotor system, or muscles that control eye movements.
"Simulator sickness is very common," said David Whittinghill, an assistant professor in Purdue University's Department of Computer Graphics Technology. "The problem is your perceptual system does not like it when the motion of your body and your visual system are out of synch. So if you see motion in your field of view you expect to be moving, and if you have motion in your eyes without motion in your vestibular system you get sick."
Anecdotal evidence has suggested simulator sickness is less intense when games contain fixed visual reference objects - such as a racecar's dashboard or an airplane's cockpit - located within the user's field of view.
"But you can't have a cockpit in every VR simulation," Whittinghill said.
His research team was studying the problem when undergraduate student Bradley Ziegler suggested inserting the image of a virtual human nose in the center of the video display.
"It was a stroke of genius," said Whittinghill, who teaches video game design. "You are constantly seeing your own nose. You tune it out, but it's still there, perhaps giving you a frame of reference to help ground you."
The researchers have discovered that the virtual nose, or "nasum virtualis," reduces simulator sickness when inserted into popular games.
Findings were presented earlier this month during the Game Developers Conference in San Francisco. Also working on the research are undergraduates James Moore and Tristan Case.
Forty-one test subjects operated a number of virtual reality applications of varying motion intensity while wearing a virtual reality headset. In one of the applications, the user navigates the interior of a Tuscany villa. In another, it's the white-knuckle thrill ride of a roller coaster.
Some of the subjects played games containing the virtual nose, while others played standard versions. They were not told that the nose was there.
"Surprisingly, subjects did not notice the nasum virtualis while they were playing the games, and they were incredulous when its presence was revealed to them later in debriefings," Whittinghill said.
Findings showed the virtual nose allowed people using the Tuscany villa simulation to play an average of 94.2 seconds longer without feeling sick, while those playing the roller coaster game played an average of 2.2 seconds longer.
"The roller coaster demo is short, but it's very intense at times, spinning upside down, jumping across chasms, plunging fully vertical, so people can't do it very long under the best of circumstances," Whittinghill said. "We had a reliable increase of 2 seconds, and it was a very clear trend. For the Tuscany demo it takes more time, but eventually you start getting queasy, and 94 seconds is a huge improvement."
Researchers also used electro dermal activity (EDA) sensors to record electrical conduction across the skin, which is affected by sweating due to excitement, a proxy indication of simulator sickness. The measurements indicated EDA differences between subjects playing games with the nose and without.
It isn't clear why the virtual nose evidently reduces simulator sickness.
"Our suspicion is that you have this stable object that your body is accustomed to tuning out, but it's still there and your sensory system knows it," he said.
The research is ongoing.
"Our long-term goal is to create a fully predictive model of simulator sickness that will allow us to predict, given a specific set of perceptual and individual inputs, what level of simulator sickness one can expect," Whittinghill said.
