One of the more entertaining side effects of virtual reality is what happens when people forget the boundaries of reality. From users falling over after attempting to lean on virtual desks, to people trying to poke their heads into non-existent holes, these clips are (often comical) evidence of VR’s ability to trick our brains into confusing the lines between real and virtual worlds.

Researchers at the University of Tokyo have been developing ways to harness this tendency to merge virtual and physical environments. One example of this is an “unlimited corridor” – giving a person the illusion of walking alongside an endless straight wall, when they are in fact moving around a circular set.

The project has been led by Dr Takuji Narumi, alongside Unity researcher, product evangelist and education lead Yohei Yanase. It is based on what Narumi describes as a “visuo-haptic redirected walking technique”, which works by tricking the brain into thinking the curved surface of the wall is straight.

“If the users want to walk straight in the virtual environment with the method, the camera (which equals the user’s eye position) rotates little by little, to redirect the users to walk along a circular path in reality,” Narumi tells me.

See related The next Pokémon Go will let you touch virtual worlds Can virtual reality ever surprise us like early cinema did? Virtual reality will change the way you think about violence As well as manipulation ofto the VR camera’s position, Narumi explains that the physical contact (haptic sensation) of touching the wall is an important part of modifying a user’s spatial perception. It is this combination of visual and haptic cues that allows a person to “explore virtual environments on foot unlimitedly by touching walls, although they are walking around circular walls within a space just 5 x 7 metres in size”.

The circular set can accommodate a number of players simultaneously, although it looks like their journeys need to be carefully choreographed to avoid crashes. The researchers say the “unlimited corridor” could be used in theme parks, for horror or maze running experiences, or for education and training. Narumi makes it clear, however, that the curved set is only a starting point. The next step is to remove the need for static walls.

“Haptics is the most important part [of the future of VR], but it can be presented without physical setups,” he says. “As a first step to investigate our idea, we used the static curvature walls in the temporal system…We believe the method can be improved by using environmental objects in your home, [such as] a desk, wall and sofa, for presenting users [with] haptic cues.”

(Above: Microsoft has said its upcoming HoloLens headset will blend physical and virtual environments)

Creating virtual environments with nothing more than your living-room walls and dining-room table might sound like a science fiction version of the lava game, and will probably result in more than a few broken picture frames, but Narumi believes this “cross-modal” effect will be a key part of next-generation VR.

“It has long been thought that different sensory modalities operate independent of each other,” he says. “However, recent behavioral and brain-imaging studies are changing this view, now suggesting that cross-modal interactions have an important role in our perception. In cross-modal effects, the perception of a sensation through one sense is changed by other stimuli that are simultaneously received through other senses.”

Another project spearheading the use of “cross-modal” effects is the Meta Cookie experiment, also run by Narumi’s team at the University of Tokyo. Instead of physical walls, this project uses augmented reality to change the appearance of a plain cookie, and scented air to change the way it smells. This changes the subject’s perception of taste, making the user feel like they are eating a chocolate cookie, for example.

The use of scent and appearance to affect the impression of taste is nothing new – restaurants have been doing this for centuries – but the combination with VR gives a fascinating glimpse into the future of virtual and augmented reality. In a world where our senses can be so easily manipulated, will we change the way we think about the world around us?

Well, at least holidays “abroad” will be cheaper.