Object orientation and location updating during nonvisual navigation: The characteristics and effects of object-versus trajectory-centered processing modes

Abstract

The present study investigates the effect of two distinct processing modes on object location and appearance updating during a guided walk without vision. As a calibration procedure, 12 subjects rotated a head-fixed miniature model until it matched the memorized orientation of the corresponding object, to measure initial (mis)perception of object orientation before the walking task. In the main experiment, observers either continuously kept track of the memorized object appearance during the walk (object-centered task), or they deduced object attributes at a terminal viewing position from continuous trajectory-mapping and knowledge of the object appearance at the initial position (trajectory-centered task), depending on the experimental session. Heading toward the memorized object location and object model rotation supplied information on respectively object location and orientation. Results showed that the two processing modes affected differently spontaneous walk velocity, object orientation updating and retrieval time. Estimation of walked distance and spatial inference processes are the two main sources of errors when updating object location and orientation while walking blind under external guidance.

This research was supported by a doctoral Grant from the Centre National d'Etudes Spatiales to the first author. We thank Michel Ehrette and Michel Loiron for the technical assistance they provided, respectively, in the stimuli fabrication and HF transmission setting up.