First, you need a Gestalt : An interaction of bottom-up and top-down streams during the perception of the ambiguously rotating human walker

Faculty/Professorship: General Psychology and Methodology  
Author(s): Pastukhov, Alexander  
Title of the Journal: Scientific reports
ISSN: 2045-2322
Publisher Information: London : Macmillan Publishers Limited, part of Springer Nature
Year of publication: 2017
Volume: 7
Issue: 1158
Pages: 7
Language(s): English
DOI: 10.1038/s41598-017-01376-1
Our visual system combines sensory evidence with prior knowledge to produce a representation of an outside world. Here, we explored the limits of the feedforward computation using an ambiguously rotating human biological motion. Specifically, we investigated whether an overall rotation, which was added to all the displays used in the study, would be perceived when the point-light walker was presented upside-down, a condition that typically obliterates perception of a human Gestalt. We report that inversion of the point-light walker or the absence of an identifiable Gestalt abolished the perception of an overall rotation. Perception of rotation was restored if the human walker Gestalt could be identified (an upright walker), if observers were informed about the nature of the motion display, or if observers expected to see the rotation of an unknown dynamic object. This implies that a mathematically more complex human motion was accounted for before the remaining motion components could be used to infer an overall rotation. Our results indicate that the perceptual inference does not proceed in a hierarchical manner with the simpler components being identified first. Instead, prior knowledge acts as a starting point for the decomposition of an even relatively simple combination of two motions.
Keywords: motion detection, object vision
Open Access Journal: Ja
Type: Article
Release Date: 26. January 2023
Project: Open-Access-Publikationsfonds 2012-2020