Abstract
AbstractOur brain combines sensory inputs from various sources by dynamically weighting cues according to their reliability and relevance for a given task. In our daily lives, one such task is to navigate familiar but also unknown environments, as we move from place to place. Two pertinent cues in navigation are the spatial arrangement of landmarks, and the continuous path integration of travelled distances and changes in direction. Although several modelling studies have shown that Bayesian integration of cues provides a good explanation for navigation in environments with up to three objects at the population level, it remains unclear how navigation of individuals is affected by more complex environments. To investigate how humans process and combine cues of varying reliability about landmarks and path integration in complex environments, we conducted virtual reality experiments. We varied the number of landmarks to study navigation in environments ranging from an open steppe to a dense forest, thus going beyond environments with three landmarks that have been studied in the past. We analysed spatial behaviour at both the population and individual level with linear regression models and developed a computational model, based on maximum likelihood estimation (MLE), to infer the underlying dynamic combination of cues. With more than three landmarks, individual differences between participants in the use of cues are striking. For some, the addition of landmarks does not worsen their performance, whereas for others it seems to impair their use of landmark information. It appears that navigation success in complex environments depends on the ability to identify the correct clearing around the goal location, suggesting that some participants may not be able to see the forest for the trees while others do.Author summaryImagine you wake up in the morning in the middle of a forest. It is chilly, and you have no phone or GPS connection. Leaving your backpack behind, you meander through the terrain in quest for firewood and eventually want to return to your belongings. How do you navigate? We investigated this exact question using a first-person computer game, behavioural data and computational modelling. Naturally, your strategy depends on the features that the landscape offers: deserts are different from forests. In principle, all people can use surrounding objects (landmarks) and keep track of the path they walked (path integration). We found that while some people are good navigators in all different scenarios, from open steppes to dense vegetation, others can’t see the forest for the trees.
Publisher
Cold Spring Harbor Laboratory