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Abstract

In visual navigation, landmarks can be used in a number of different ways. In this paper we investigate the role of global and local landmarks in virtual environment navigation. We performed an experiment in a virtual environment called ``Hexatown''. Hexatown consists of a regular hexagonal grid of junctions joined together by streets. At each junction there are three buildings, or other objects. Additionally, we provide global direction or
compass information by three distant ``global landmarks'' (a hilltop and a television tower at a mountain range, and a skyline of a distant city). Participants navigated in Hexatown by pressing the buttons of a computer mouse. According to their movement decisions, egomotion was
simulated. Participants had to learn the route back and forth between two specific buildings. In the test-phase individual junctions were approached and the participants' movement decision was recorded. We performed two experiments
with the same task but different paradigms. In the first experiment we used conflicting cues by transposing one landmark type after learning. In the second experiment we reduced either the local or the global landmark information after training. Results show that both local and global landmarks are used in the decisions for the way-finding task. Different participants rely on different strategies to make navigation decisions. In the first experiment (cue conflict), some of the participants used only local landmarks while others relied exclusively on global landmarks. Still other participants used local landmarks at one location and global landmarks at the other location. When removing one landmark type in the second experiment, the other type could be used by almost all participants.