Sibylle D. Steck

Geographical Slant Facilitates Navigation and Orientation in Virtual Environments

Theoretical considerations and earlier experimental findings indicate that traveling over slanted terrain can lead to an enrichment of the perceived spatial cues relevant for navigation. We investigated the proposed facilitation of a uniformly slanted environment on navigation and orientation performance with a virtual environment presented on a large 180° screen, using as material a virtual town with eight places and twenty-four landmarks. In the control condition, this town was placed on a flat surface; in the two experimental conditions, the town was placed on a slope with a uniform angle of 4°. Pedaling on a bicycle simulator, participants first explored the environment, then solved navigation tasks, pointed from various positions to distant landmarks, judged the relative elevation of pairs of distant landmarks from memory, and finally drew a sketch map of the environment. In comparison to the control condition, the number of navigation errors was significantly lower in the slanted conditions, and the deviations in the pointings to distant landmarks were massively reduced. Participants from the slant conditions also showed good knowledge of the relative elevations of pairs of distant locations. However, no differences in map-drawing quality were found. The results lend additional support to the proposition that our spatial knowledge, which is used in navigation and orientation, contains vertical information.

The role of geographical slant in virtual environment navigation

We investigated the role of geographical slant in simple navigation and spatial memory tasks, using an outdoor virtual environment. The whole environment could be slanted by an angle of 4?. Subjects could interact with the virtual environment by pedaling with force-feedback on a bicycle simulator (translation) or by hitting buttons (discrete rotations in 60? steps). After memory acquisition, spatial knowledge was accessed by three tasks: (i) pointing from various positions to the learnedgoals; (ii) choosing the more elevatedof two landmarks from memory; (iii) drawing a sketch map of the environment. The number of navigation errors (wrong motion decisions with respect to the goal) was significantly reducedin the slanted conditions. Furthermore, we foundthat subjects were able to point to currently invisible targets in virtual environments. Adding a geographical slant improves this performance. We conclude that geographical slant plays a role either in the construction of a spatial memory, or in its readout, or in both.