Document Detail


Visual processing of rotary motion.
MedLine Citation:
PMID:  2011455     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Local descriptions of velocity fields (e.g., rotation, divergence, and deformation) contain a wealth of information for form perception and ego motion. In spite of this, human psychophysical performance in estimating these entities has not yet been thoroughly examined. In this paper, we report on the visual discrimination of rotary motion. A sequence of image frames is used to elicit an apparent rotation of an annulus, composed of dots in the frontoparallel plane, around a fixation spot at the center of the annulus. Differential angular velocity thresholds are measured as a function of the angular velocity, the diameter of the annulus, the number of dots, the display time per frame, and the number of frames. The results show a U-shaped dependence of angular velocity discrimination on spatial scale, with minimal Weber fractions of 7%. Experiments with a scatter in the distance of the individual dots to the center of rotation demonstrate that angular velocity cannot be assessed directly; perceived angular velocity depends strongly on the distance of the dots relative to the center of rotation. We suggest that the estimation of rotary motion is mediated by local estimations of linear velocity.
Authors:
P Werkhoven; J J Koenderink
Related Documents :
16530245 - Capture of visual direction in dynamic vergence is reduced with flashed monocular lines.
15929645 - Local and global segmentation of rotating shapes viewed through multiple slits.
1771135 - The detectability of geometric structure in rapidly changing optical patterns.
12729385 - The aperture problems in the pulfrich effect.
10087025 - Formate-induced inhibition of photoreceptor function in methanol intoxication.
19724525 - Optimal illumination for discriminating objects with different spectra.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Perception & psychophysics     Volume:  49     ISSN:  0031-5117     ISO Abbreviation:  Percept Psychophys     Publication Date:  1991 Jan 
Date Detail:
Created Date:  1991-05-08     Completed Date:  1991-05-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0200445     Medline TA:  Percept Psychophys     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  73-82     Citation Subset:  C    
Affiliation:
Utrecht University, The Netherlands.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Depth Perception*
Humans
Motion Perception*
Orientation*
Psychophysics
Vision Disparity

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Same-different judgments of multiletter strings: insensitivity to positional bias and spacing.
Next Document:  Exogenous and endogenous control of attention: the effect of visual onsets and offsets.