Subscribe | UPI Odd Newsletter Subscribe STOCKHOLM, Sweden, May 27 (UPI) -- Swedish scientists said they were able to convince subjects to operate under the illusion of being the size of a Barbie doll or 13 feet tall. The scientists at the Karolinska Institutet in Stockholm said they showed 198 people images of dolls -- alternately a Barbie-sized doll and a 13-foot-tall doll -- having their legs stroked while their own legs were stroked, The Local reported Friday. Advertisement The subjects were then asked to estimate the sizes of differently-sized blocks and were asked to walk over to them with their eyes closed. They found those shown images of the Barbie-sized doll overestimated the distance to the blocks as well as the size of the objects, while those shown images of the larger doll underestimated the measurements. "It is a really strong illusion, even when you know that you are being fooled you still believe it," said Bjorn van der Hoort, neurologist at Karolinska Institutet.