Learning to navigate: experience versus maps.

People use "route knowledge" to navigate to targets along familiar routes and "survey knowledge" to determine (by pointing, for example) a target's metric location. We show that both root in separate memories of the same environment: participants navigating through their home city relied on representations and reference frames different from those they used when doing a matched survey task. Tübingen residents recalled their way along a familiar route to a distant target while located in a photorealistic virtual 3D model of Tübingen, indicating their route decisions on a keyboard. Participants had previously done a survey task (pointing) using the same start points and targets. Errors and response latencies observed in route recall were completely unrelated to errors and latencies in pointing. This suggests participants employed different and independent representations for each task. Further, participants made fewer routing errors when asked to respond from a horizontal walking perspective rather than a constant aerial perspective. This suggests that instead of the single reference, north-up frame (similar to a conventional map) they used in the survey task, participants employed different, and most probably multiple, reference frames learned from "on the ground" navigating experience. The implication is that, within their everyday environment, people use map or navigation-based knowledge according to which best suits the task.