Disentangling spatial conflicts in mental perspective taking

The present experiment was conducted to examine the cognitive processes underlying mental perspective taking in remembered environments. Participants learned a layout of everyday objects from multiple randomly chosen perspectives. They were then blindfolded and tested for their spatial knowledge by having them point to unseen object locations from imagined perspectives. The acoustic display of a first object name informed participants about the to-be-imagined position, a second object name about the to-be-imagined heading, before a third object name identified the target they should point to with a joystick. The choice of object triplets allowed for independent variation of head-direction disparity (HDD), i.e., the difference in heading direction between real and imagined perspective, and object direction disparity (ODD), i.e., the egocentric shift of target object direction between real and imagined perspectives. Results revealed a consistent pattern of monotonic increasing detrimental effects of HDD (0°, 60°, 120°, 180°) and ODD (0-45°, 46-90°, 91-135°, 136-180°). The independent variation of HDD and ODD disclosed a third source of extra processing costs that could be traced back to allocentric differences in target object direction (ODD_allo). A SOA-interval (1, 3, or 5 s) before target presentation allowed participants to save on overall pointing times and errors but did not allow them to reduce incremental costs from HDD, ODD_ego, or ODD_allo. The present results reveal that multiple overlapping spatial interference conflicts between real and imagined spatial perspectives are the most important source of additional processing costs in mental perspective taking in remembered environments.