No single, stable 3D representation can explain pointing biases in a spatial updating task

• Published in: bioRxiv
• Main Authors: Vuong, Jenny, Fitzgibbon, Andrew, Glennerster, Andrew
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 12.02.2019
• Subjects: Binocular vision
• DOI: 10.1101/390088

People are able to keep track of objects as they navigate through space, even when objects are out of sight. This requires some kind of representation of the scene and of the observer's location but the form this representation might take is debated. We tested the accuracy and reliability of observers' estimates of the visual direction of previously-viewed targets. Participants viewed 4 objects from one location, with binocular vision and small head movements giving information about the 3D locations of the objects. Without any further sight of the targets, participants walked to another location and pointed towards them. All the conditions were tested in an immersive virtual environment and some were also carried out in a real scene. Participants made large, consistent pointing errors that are poorly explained by any consistent 3D representation. Instead, if a 3D representation is to account for the data it would need to be one where the target boxes were squashed, almost into a plane, quite far away from the true location of the boxes and in different places depending on the orientation of the obscuring wall at the moment the participant points. In short, our data show that the mechanisms for updating visual direction of unseen targets are not based on a stable 3D model of the scene, even a distorted one. Footnotes * Revised throughout in response to reviewers' comments. Main changes are to the Discussion. * https://github.com/jnyvng/PointingData * http://www.jennyvuong.net/dataWebsite/