Measuring presence is critical to improving user involvement and performance in Mixed Reality (MR). \emph{Presence}, a crucial aspect of MR, is traditionally gauged using subjective questionnaires, leading to a lack of time-varying responses and susceptibility to user bias. Inspired by the existing literature on the relationship between presence and human performance, the proposed methodology systematically measures a user's reaction time to a visual stimulus as they interact within a manipulated MR environment. We explore the user reaction time as a quantity that can be easily measured using the systemic tools available in modern MR devices. We conducted an exploratory study (N=40) with two experiments designed to alter the users' sense of presence by manipulating \emph{place illusion} and \emph{plausibility illusion}. We found a significant correlation between presence scores and reaction times with a correlation coefficient -0.65, suggesting that users with a higher sense of presence responded more swiftly to stimuli. We develop a model that estimates a user's presence level using the reaction time values with high accuracy of up to 80\%. While our study suggests that reaction time can be used as a measure of presence, further investigation is needed to improve the accuracy of the model.

翻译：测量存在感对于提升用户在混合现实（MR）中的参与度和表现至关重要。作为MR的关键方面，存在感传统上通过主观问卷进行评估，这导致缺乏时变响应且易受用户偏差影响。受现有关于存在感与人类表现之间关系文献的启发，本研究提出一种系统方法，通过测量用户在受控MR环境中对视觉刺激的反应时间进行探索。我们将用户反应时间作为可利用现代MR设备中系统工具轻松测量的量进行分析。我们进行了一项探索性研究（N=40），包含两个实验，通过操纵场所幻觉和可信度幻觉来改变用户的存在感。研究发现存在感评分与反应时间之间存在显著相关性，相关系数为-0.65，表明存在感更强的用户对刺激的反应更迅速。我们构建了一个基于反应时间值估计用户存在感水平的模型，其准确率高达80%。尽管研究表明反应时间可作为存在感的度量指标，但进一步提高模型精度仍需深入研究。