Jump to ContentJump to Main Navigation
The Oxford Compendium of Visual Illusions$
Users without a subscription are not able to see the full content.

Arthur G. Shapiro and Dejan Todorovic

Print publication date: 2017

Print ISBN-13: 9780199794607

Published to Oxford Scholarship Online: June 2017

DOI: 10.1093/acprof:oso/9780199794607.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (oxford.universitypressscholarship.com). (c) Copyright Oxford University Press, 2021. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 28 September 2021

Objectless Motion

Objectless Motion

The Pedestalled Motion Paradigm

(p.573) Chapter 79 Objectless Motion
The Oxford Compendium of Visual Illusions

George Sperling

Zhong-Lin Lu

Oxford University Press

The sum of two sine waves of the same frequency is yet another sine wave. When a moving sinewave grating (e.g., continuously translating from left to right) is added to (superimposed on) a stationary sinewave grating (the pedestal) with twice the amplitude, the sum is a sine-wave grating that wobbles back and forth. Remarkably, the left–right direction of the moving grating can be perceived just as accurately in pedestalled motion as in normal motion. At temporal frequencies of 10 Hz and greater, the wobble is too quick to be perceived. The moving pedestalled sine-wave grating is perceived as an invisible left-to-right horizontal wind above the summed sine-wave grating that wobbles back and forth at low temporal frequencies of motion but appears to be absolutely stationary at high temporal frequencies.

Keywords:   pedestalled motion, objectless motion, sine wave, sine-wave grating, motion

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .