Abstract
The mechanisms underlying navigation in complex environments are currently not very clear, particularly the role of visual rotation information. We therefore examined the accuracy of human path integration abilities based on purely visual information (e.g., depth cues, optic flow information and landmarks), focusing mainly on the effects of self-rotation by the navigator. Participants navigated either actively or passively through realistic large-scale virtual environments in a driving simulator, along routes consisting of roads linked by a traffic circle. The environments were modelled on real New Zealand locations. Angular estimates of the starting point location were recorded for a number of different conditions. In the active mode, participants used a steering wheel, accelerator and brake pedals to control their simulated motion; whilst passive participants observed a pre-recorded route. The environments were varied between highly structured (urban) and less structured (rural) settings, in order to increase or reduce optic flow information and depth cues; and between those with landmarks present at the intersections, and those with no landmarks. Route layouts were manipulated to include different combinations of road-lengths and intersection exit-road angles. Participants were able to perform path integration using visual information, but with systematic errors. There was a clear effect of navigation mode: in all environments, participants in the active condition tended to be more accurate than those in the passive condition, except when the route consisted of a short approach road to an intersection followed by a long exit road. Clear effects of route layout were also observed: the pattern of errors (overestimation vs. underestimation of the direction of the starting location) depended on the angle-distance configuration. However, the presence of more structure and landmarks did not increase accuracy: the pattern of errors was similar between the urban and rural environments, and between environments with and without landmarks.
The New Zealand Road Safety Trust.