Global versus Local Cues for Route Finding in Virtual Environments

Abstract

Motivated by the results of Gillner and Mallot (1996 Perception25 Supplement, 93) implying that local views are basic elements for a spatial representation, we studied the role of global versus local landmarks using a route-finding task. Our hypotheses were: (i) A global navigation strategy relying on allocentric movement decisions is used, eg “go from this place towards the chapel on the hill”, or (ii) a local navigation strategy based on view—movement associations is used, eg “at the red building go right”. We performed an experiment in a computer graphics town based on a hexagonal grid structure. At each intersection we placed three different buildings. We also provided global direction information by placing six global landmarks distributed equally along a mountain range. Subjects had to learn the back and forth route between two buildings, not knowing that after a learning phase the location of buildings at a particular junction would be changed. These changes produced conflicting global and local information. In the test-phase, the subject approached individual junctions in both learned and novel directions and the movement decisions were recorded. In a control condition with unchanged places twenty subjects made correct decisions for 136 of 160 movements. In the experimental conflict condition 123 decisions were consistent with a local and 37 with a global strategy. This supports our previous finding that local views play a dominant role in making route judgements. Approaching a junction from a learned direction leads to more accurate movement decisions than approaching it from a novel direction, even if the global landmarks are available, which provides further support for the local-view hypothesis.