Frontal extents in virtual environments are not immune to underperception.

Distance is commonly underperceived by up to 50 % in virtual environments (VEs), in contrast to relatively accurate real world judgments. Experiments reported by Geuss, Stefanucci, Creem-Regehr, and Thompson (Journal of Experimental Psychology: Human Perception and Performance, 38, 1242-1253, 2012) indicate that the exocentric distance separating two objects in a VE is underperceived when the objects are oriented in the sagittal plane (depth extents), but veridically perceived when oriented in a frontoparallel plane (frontal extents). The authors conclude that "distance underestimation in the [VE] generalizes to intervals in the depth plane, but not to intervals in the frontal plane." The current experiment evaluated an alternative hypothesis that the accurate judgments of frontal extents reported by Geuss et al. were due to a fortunate balance of underperception caused by the VE and overperception of frontal relative to depth extents. Participants judged frontal and depth extents in the classroom VE used by Geuss et al. and in a sparser VE containing only a grass-covered ground plane. Judgments in the classroom VE replicated findings by Geuss et al., but judgments in the grass VE show underperception of both depth and frontal extents, indicating that frontal extents are not immune to underperception in VEs.

Recalibration of perceived distance in virtual environments occurs rapidly and transfers asymmetrically across scale.

Distance in immersive virtual reality is commonly underperceived relative to intended distance, causing virtual environments to appear smaller than they actually are. However, a brief period of interaction by walking through the virtual environment with visual feedback can cause dramatic improvement in perceived distance. The goal of the current project was to determine how quickly improvement occurs as a result of walking interaction (Experiment 1) and whether improvement is specific to the distances experienced during interaction, or whether improvement transfers across scales of space (Experiment 2). The results show that five interaction trials resulted in a large improvement in perceived distance, and that subsequent walking interactions showed continued but diminished improvement. Furthermore, interaction with near objects (1-2 m) improved distance perception for near but not far (4-5 m) objects, whereas interaction with far objects broadly improved distance perception for both near and far objects. These results have practical implications for ameliorating distance underperception in immersive virtual reality, as well as theoretical implications for distinguishing between theories of how walking interaction influences perceived distance.