With mixed-reality devices (which combine virtual and augmented reality), such as Meta's Quest 3 or Apple's forthcoming Vision Pro, what you feel is real is called "presence."
Now researchers at the University of Massachusetts Amherst have identified reaction time as a possible way to adjust presence. That's better than asking the user to respond to a questionnaire after exiting, they note.
To test this, the researchers put participants in modified “Fruit Ninja” mixed-reality scenarios. In one experiment, they adjusted place illusion and the fruit appeared either as lifelike fruit or abstract cartoons. In another experiment, they created a plausibility illusion by showing mugs filling up with coffee, either in the correct upright position or sideways.
They found that people were quicker in reacting to the lifelike fruit than they would to the cartoonish-looking food.
Important in medical procedures
Yasra Chandio, doctoral candidate in computer engineering and lead study author, gives medical procedures as an example of the importance of this real-time presence calibration: If a surgeon needs millimeter-level precision, they may use mixed reality as a guide to tell them exactly where they need to operate.
“If we just show the organ in front of them, and we don’t adjust for the height of the surgeon, for instance, that could be delaying the surgeon and could have inaccuracies for them,” she says. Low presence can also contribute to cybersickness, a feeling of dizziness or nausea that can occur in the body when a user’s bodily perception does not align with what they’re seeing.
However, if the mixed-reality system is internally monitoring presence, it can make adjustments in real time, like moving the virtual organ rendering to eye level.
Citation: Y. Chandio, N. Bashir, V. Interrante and F. M. Anwar, "Investigating the Correlation Between Presence and Reaction Time in Mixed Reality," in IEEE Transactions on Visualization and Computer Graphics, doi: 10.1109/TVCG.2023.3319563