title: Neural correlates of real-world route learning.
abstract: Classical theories of spatial microgenesis (Siegel and White, 1975) posit that information about landmarks and the paths between them is acquired prior to the establishment of more holistic survey-level representations. To test this idea, we examined the neural and behavioral correlates of landmark and path encoding during a real-world route learning episode. Subjects were taught a novel 3 km route around the University of Pennsylvania campus and then brought to the laboratory where they performed a recognition task that required them to discriminate between on-route and off-route buildings. Each building was preceded by a masked prime, which could either be the building that immediately preceded the target building along the route or immediately succeeded it. Consistent with previous reports using a similar paradigm in a virtual environment (Janzen and Weststeijn, 2007), buildings at navigational decision points (DPs) were more easily recognized than non-DP buildings and recognition was facilitated by in-route vs. against-route primes. Functional magnetic resonance imaging (fMRI) data collected during the recognition task revealed two effects of interest: first, greater response to DP vs. non-DP buildings in a wide network of brain regions previously implicated in spatial processing; second, a significant interaction between building location (DP vs. non-DP) and route direction (in-route vs. against-route) in a retrosplenial/parietal-occipital sulcus region previously labeled the retrosplenial complex (RSC). These results indicate that newly learned real-world routes are coded in terms of paths between decision points and suggest that the RSC may be a critical locus for integrating landmark and path information.
authors.affiliation: Department of Psychology, Center for Cognitive Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA. schinazi@sas.upenn.edu
authors.forename: Victor R
authors.initials: VR
authors.lastname: Schinazi
authors.forename: Russell A
authors.initials: RA
authors.lastname: Epstein
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D003657:Decision Making / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009778:Occipital Lobe / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D020534:Parahippocampal Gyrus / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology*; D055815:Young Adult