Get ready for your next virtual sword fight to feel even more real, thanks to a breakthrough at UMass Amherst. In what could be a game changer for mixed reality technology, researchers have discovered that reaction time can seriously gauge how immersed you are in a digital scenario, making mixed reality experiences more authentic and, well, less nauseating.

Fatima Anwar, the brainy assistant professor of electrical and computer engineering at UMass, lit up the scene by laying down the facts. "In virtual reality, the user is in the virtual world; they have no connection with the physical world around them," she explained in the UMass News. And while she said, "Mixed reality is a combination of both," the real deal is that it could help pros like surgeons slice with pinpoint accuracy.

Fatima Anwar and her crew see this slicing-and-dicing technology boosting everything from education to construction and healthcare. But there's a catch: it's all about the 'presence.' That's you feeling like you're really there. That's the secret sauce. And it's something they used to just ask you about after you took the headset off. 

Let's dive into the nerdy part: To crack the code on presence, the research team, which included hotshot doctoral candidate Yasra Chandio, cooked up a series of experiments. They took Fruit Ninja and gave it a twist—no scoring, just playing with how the in-game goodies looked and acted to see how people would react. They were on to something when they saw folks were ninja-chopping faster at realistic-looking fruit than at the cartoony stuff. Essentially, "Reaction time is associated with presence such that slow reaction time indicates low presence and high reaction time indicates high presence with 80% predictive accuracy even with the small dataset," Chandio dished in the UMass report.

But here's the kicker: They're talking real-time adjustments to the mixed reality experience while you're still in it, so if your brain's telling your hands, "this doesn't feel right," the system can shift gears and make the virtual world more in tune with what your nose expects. It tackles that icky feeling called cybersickness—yeah, it's as gross as it sounds—where your brain and your body ain't playing nice together because things just seem off. "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," explains Chandio.

It might seem like a no-brainer to just make everything super realistic from the get-go, but the catch is that we're all a bit different. What works for one might be a total failure for another. "Some people are going to argue, 'Why would you not create the best scene in the first place?' but that’s because humans are very complex," Chandio said.