“Both illusions were cool, but if I have to choose which one I preferred, I would have to say the Barbie,” Björn van der Hoort, neurologist at Karolinska Institutet, told The Local.
In the experiment, 198 people were shown images of a doll – a Barbie-sized one and a giant one – having their legs stroked. At the same time the subject's legs were stroked – causing the illusion that what they saw was what they felt.
After that the subjects were asked to estimates the size of differently sized blocks and then walk over these with their eyes shut.
The result showed that for the subjects touched as a Barbie-doll, the blocks were estimated as very large.
Where the 4–metre doll had been used the blocks were perceived as tiny. The distances between the blocks were over- and under-estimated in a similar manner.
The experiment indicates that how we perceive size and distance is universal and almost all test subjects had the same experience.
“It is a really strong illusion, even when you know that you are being fooled you still believe it," said van der Hoort.
The conclusion is that we all use our bodies as reference points to which we compare everything around us, a behaviour that most likely stems from evolution according to van der Hoort.
“There was a time when we didn't care about measuring distances in metres but instead cared about how many steps it would take for us to reach something or how far apart we had to hold our hands to grasp something. The body was compared to the world we had to interact with," van der Hoort said.
This also brings light to the quite common phenomenon when a place often frequented as a child seems much smaller then remembered when you return as an adult.
“We think this is why, that when you were a child you compared the dimensions of the place to your small body and now you have a big body – which changes your perception of the dimensions,” he said.
Although the research is still in its fundamental stages, it opens up for the possibility of developing fields like robotics, according to van der Hoort.
“Today when we operate a robot, for example to repair an oil-rig deep under the sea or perhaps cleaning a power plant, we push buttons and pull levers, but our research can change that,“ he said.
In the future it may be possible for the robot's operator to really feel he is the robot, on site, doing the work. Another future application could be a surgeon "becoming a tiny robot and walking into someone's ear performing surgery", although such developments are at east 10-15 years away, according to van der Hoort.
“But when it is developed it will make science more intuitive and more efficient, we think," he told The Local.
The findings have been published in online scientific journal PLoS ONE.