ISSN : 1226-9654
가상환경을 경험할 때 발생하는 사이버멀미는 일반적인 멀미와 유사한 증상으로 그 정확한 기저 원인 및 완전한 해결 방법은 현재까지 밝혀지지 않았다. 본 연구에서는 가상환경에서 안정적인 정지좌표계 선택에 도움을 주는 독립적 시각 전경(Independent Visual Foreground: IVF)의 사이버멀미 감소 효과를 검증하고자 한다. 이를 위해 22명의 피험자들은 약 2주 간격으로 독립적 시각 전경이 있는 조건(IVF 조건)과 없는 조건(No-IVF 조건)에서 모두 가상환경을 경험하였다. 각 조건에서 사이버멀미의 정도를 측정하기 위한 주관적인 지표로 자기보고와 Simulator Sickness Questionnaire(SSQ) 척도를 사용하였고 심리생리적인 지표로 위장전위(electrogastrogram: EGG)를 측정하였다. 또한 IVF가 가상환경에서의 현실감 변화에 미치는 영향을 Presence Questionnaire(PQ) 척도를 사용하여 평가하였다. 그 결과 가상환경 경험단계에서 IVF를 사용하였을 때 위장전위의 정상 주파수 대역 잔여비율은 유의미하게 높았고 위빈맥(tachygastria) 주파수 대역 잔여비율은 유의미하게 낮았다. 그리고 가상현실 경험단계에서 SSQ 점수와 각 EGG 주파수 대역 잔여비율은 유의미한 상관관계를 보여주었다. 하지만 조건 간의 PQ 점수는 유의미한 차이를 나타내지 않았다. 이러한 결과들을 통해 EGG가 사이버멀미의 주요한 예측변인 중 하나이며 가상환경에서 IVF를 제시하였을 때 사이버멀미와 연관된 자율신경계 증상이 줄어들었음을 알 수 있다. 또한 본 연구의 결과들은 IVF가 가상환경의 현실감은 감소시키지 않으면서 사이버멀미를 경감시키는 효과적인 솔루션으로 이용될 가능성을 시사한다.
Cybersickness accompanies a variety of autonomic symptoms that parallel symptoms of motion sickness. The underlying physiological mechanisms of cybersickness have been controversial and foolproof methods for elimination of cybersickness have not been introduced. This study investigated effects of an independent visual foreground (IVF) which could assist users in selecting a single rest frame in virtual environment (VE) to reduce cybersickness. Twenty-two subjects experienced a VE both with the IVF (IVF condition) and without the IVF (No-IVF condition) with counterbalancing for contol of order effects at an interval of two weeks. Subjective indices of cybersickness were obtained from self-reports and a simulator sickness questionnaire (SSQ). Physiological indices of cybersickness were obtained from the frequency spectrum of electrogastrogram(EGG). A presence questionnaire (PQ) was used to compare the feeling of presence in each condition. The main findings were that the residual percent of normal frequency of EGG was maintained significantly higher level and the residual percent of tachygastria frequency of EGG was maintained significantly lower level in the IVF condition than those in the No-IVF condition. There was a significant correlation between SSQ scores and frequency spectrum of EGG. However, there was no significant difference in PQ scores between IVF and No-IVF conditions, which showed that IVF did not deteriorate the feeling of presence in the VE.. These results suggest that presentation of IVF in VE reduce autonomic symptoms of cybersickness and EGG can be an objective measure of cybersickness. We suggest that use of IVF can be a promising approach to alleviate cybersickness in VE.
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