Estimating distance in real and virtual environments: Does order make a difference?

In this investigation, we examined how the order in which people experience real and virtual environments influences their distance estimates. Participants made two sets of distance estimates in one of the following conditions: (1) real environment first, virtual environment second; (2) virtual environment first, real environment second; (3) real environment first, real environment second; or (4) virtual environment first, virtual environment second. In Experiment 1, the participants imagined how long it would take to walk to targets in real and virtual environments. The participants' first estimates were significantly more accurate in the real than in the virtual environment. When the second environment was the same as the first environment (real-real and virtual-virtual), the participants' second estimates were also more accurate in the real than in the virtual environment. When the second environment differed from the first environment (real-virtual and virtual-real), however, the participants' second estimates did not differ significantly across the two environments. A second experiment, in which the participants walked blindfolded to targets in the real environment and imagined how long it would take to walk to targets in the virtual environment, replicated these results. These subtle yet persistent order effects suggest that memory can play an important role in distance perception.