Abstract
A key aspect of navigation is the ability to imagine the spatial relationships between real-world locations from different points of view. To understand the neural codes that underlie this ability, we scanned University of Pennsylvania students with fMRI while they performed a judgment of relative direction task that required them to make decisions about the locations of buildings on campus. On each 6s-trial, subjects were presented with the names of 3 buildings and were instructed to imagine that they were standing at the first building and facing the second building. They then indicated via button press whether the third building was located to their left or right given their imagined location and facing direction (i.e., their imagined view; e.g., Van Pelt Library facing East). There were 4 possible starting locations (i.e., buildings) and four possible imagined facing directions (North, South, East, or West). Multi-voxel pattern analysis (MVPA) was used to identify brain regions that code: (1) the imagined starting location, (2) the imagined facing direction, and (3) the imagined view. Preliminary results suggest that activity patterns in scene-selective parahippocampal place area (PPA) and retrosplenial complex (RSC) could distinguish between specific views during this spatial imagery task, even though no scene image was shown. In addition, RSC activity patterns distinguish between locations independent of facing direction and facing directions independent of location. These results show that PPA and RSC distinguish between specific scenes (i.e., views) during spatial imagery, and they further suggest that RSC may support allocentric spatial codes that allow one to flexibly recreate these scenes based on long-term spatial knowledge.
Meeting abstract presented at VSS 2013