A study conducted at England’s Durham University uses multisensory integration to determine how children recognize their own bodies in VR
The technology powering virtual reality is still in its infancy, and as such people are still learning how best to embrace it. The entertainment industry has been the largest driving force behind its growth, but other industries are using VR to great effect; from architecture to healthcare to shopping. While the goals of the developers may vary, how we react within a VR environment generally remains consistent across industries. What if our self-image is variable based on factors like age? What if our concept of “self” changes as we age?
A new study conducted at Durham University’s Psychology Department is using a combination of custom-built virtual reality environments and motion capture cameras to study how subjects of different ages view themselves in a virtual environment - and the results are remarkable. In tests conducted with subjects of all ages, children have shown a far greater flexibility in their sense of ownership over their virtual bodies than their adult counterparts.
“We were surprised with the extent to which children accept a body that is moving completely randomly,” said Sam Keenaghan, Ph.D student. “It really shows how flexible children’s bodily awareness is as they attempt to keep track of a body that is constantly changing and growing.”
While this understanding will help VR development in multiple fields (including entertainment), it also led the research team behind the test to reach a preliminary conclusion that children - specifically 5-year-olds - do not necessarily rely on physical movement to establish an identity of self in the same way that adults do. That suggests that the current theories of human spatial development are inadequate, which may lead to a better understanding of how we perceive ourselves in a virtual environment.
Durham University’s Psychology Department recruited both adults and 5-year-olds for the experiment. The participants then stepped into Durham’s lab, equipped with 16 Vicon Bonita cameras and Vicon Tracker software that allowed the team to precisely track participants’ movements, regardless of their age or size.
The team also leaned heavily on Vicon’s Pegasus software, a retargeting solution typically used by video game developers to map mocap data onto virtual avatars. Pegasus allowed the Durham crew to apply participants’ movements to their virtual selves in real time, and to easily manipulate variables such as virtual body size and perspective.
The children and adults were then shown first-person perspective views of their virtual bodies, with different subjects controlling avatars of different sizes; some found themselves in smaller bodies than their own, some were in bodies roughly the same size, and some were in bodies that were much larger. Some of the participants saw their real-world movements precisely mimicked in the virtual world thanks to the precision mocap cameras, while some avatars moved randomly, with no relation to the movements of the participant.
While in both age groups the size made no difference to the way the participants viewed their virtual bodies, the older group had trouble connecting to avatars that moved randomly. The younger group were able to connect to their virtual bodies despite variations in both size and movement. Virtual reality hinges on the user’s perception of their own movements in relation to what they’re seeing displayed in the headset. If children perceive that relationship differently from adults, knowing how and why could be vital to developing VR software for young audiences.
The results of the virtual body movement tests are one part of a larger body of research being conducted by Durham University. Earlier tests focused on the spatial memory of children, including an experiment where they were equipped with wands that they used to identify target objects in a virtual environment. Through deliberate design, the team “teleported” the kids within the VR environment to different locations, then asked them to use landmarks to identify the same targets, which were now hidden by obstacles. The results suggested that children’s ability to remember spatial information did not differ whether 3D landmarks or 2D landmarks were used.
Translating real-time movements into virtual spaces is no simple task for the most accommodating participants, but when the subjects are small and easily distracted, it becomes more difficult. To help track the movements of children with the precision needed for a study like this, Durham again turned to Vicon.
For the last five years, Durham has relied on Vicon’s optical systems for its motion tracking needs, but adding in children presented an extra challenge. Existing mocap gear is not scaled for five-year-olds, so the university worked with Vicon to develop child-sized straps and plates.
“We used Vicon’s mocap system with children to examine the development of bodily awareness in childhood in ways that haven’t been done before,” said Keenaghan. “The precision and reliability of the Vicon system we use is key to making this ground-breaking research possible.”
The success of its experiments has spurred the Durham team to continue working with children in similar capacities - as did the enthusiasm of the young participants, who love to “dress up like robots” when they wear motion capture trackers. The children don’t follow directions quite as well as their adult counterparts, but they tend to be more engaged in the tests and enjoy experimenting with their “cartoon bodies.” Many of the young participants are repeat subjects, and they eagerly await the next tests.
“Working with children can certainly be more challenging than working with adults, but it is definitely more fun and rewarding,” said Keenaghan. “Plus, witnessing their excitement when they put the headset on for the first time and see the environment we have created for them is a joy.”
The Durham University Psychological Department continues to gather data on spatial awareness in virtual reality for both children and adults. The implications could reach across multiple fields and help lead to better VR development.