The acquisition of survey knowledge through navigation

Background: Survey estimates such as pointing, straight line distance estimation, or finding novel shortcuts to distant locations are common tasks. Although involved reference frames and brain areas were examined the underlying processing is widely unknown. Aims: We examined how experience influences the development of survey knowledge. Method: Participants learned a simple multi-corridor layout by walking forwards and backwards through a virtual environment. Throughout learning, participants were repeatedly asked to perform in pairwise pointing from each turn between segments to each other turn. Results and Conclusions: Pointing latency increased with pointing distance and decreased with pointing experience, but not with learning experience. From this observation, we conclude that participants did not access an encoded representation when performing survey tasks, but instead performed an on-the-fly construction of the estimates which was quicker for nearby goals and became faster with repeated construction, but not with learning of the underlying elements. This could involve mental travel to the target location, or the incremental construction of a mental model of non-visible object locations. Furthermore, participants made systematic errors in pointing, for example, mixed up turns or forgot segments. Modelling of underlying representations based on different error sources all suggest that participants did not create one unified representation when internally constructing the experimental environment, but instead constructed aunique representation at least for each orientation the environment was navigated. We do not find indications that this separation changed with experience or other individual differences