| Motion sharpening and contrast: gain control precedes compressive non-linearity? | |
| | |
MedLine Citation:
|
PMID: 12705958 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Blurred edges appear sharper in motion than when they are stationary. We (Vision Research 38 (1998) 2108) have previously shown how such distortions in perceived edge blur may be accounted for by a model which assumes that luminance contrast is encoded by a local contrast transducer whose response becomes progressively more compressive as speed increases. If the form of the transducer is fixed (independent of contrast) for a given speed, then a strong prediction of the model is that motion sharpening should increase with increasing contrast. We measured the sharpening of periodic patterns over a large range of contrasts, blur widths and speeds. The results indicate that whilst sharpening increases with speed it is practically invariant with contrast. The contrast invariance of motion sharpening is not explained by an early, static compressive non-linearity alone. However, several alternative explanations are also inconsistent with these results. We show that if a dynamic contrast gain control precedes the static non-linear transducer then motion sharpening, its speed dependence, and its invariance with contrast, can be predicted with reasonable accuracy. |
| | |
Authors:
|
Stephen T Hammett; Mark A Georgeson; Samantha Bedingham; Gillian S Barbieri-Hesse |
Related Documents
:
|
1215118 - Anchor effects and figural aftereffects: a comparative psychophysical investigation. 19289828 - Natural images dominate in binocular rivalry. 20928888 - The contribution of chemical exchange to mri frequency shifts in brain tissue. 15482808 - A visual mechanism tuned to black. 21810438 - Similar neural adaptation mechanisms underlying face gender and tilt aftereffects. 2934508 - Inhibitory component of externally controlled covert orienting in visual space. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Vision research Volume: 43 ISSN: 0042-6989 ISO Abbreviation: Vision Res. Publication Date: 2003 May |
Date Detail:
|
Created Date: 2003-04-22 Completed Date: 2003-07-21 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0417402 Medline TA: Vision Res Country: England |
Other Details:
|
Languages: eng Pagination: 1187-99 Citation Subset: IM |
Affiliation:
|
Department of Psychology, Royal Holloway College, University of London, Egham, Surrey TW20 0EX, UK. s.hammett@rhul.ac.uk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Contrast Sensitivity
/
physiology* Humans Models, Psychological* Motion Perception / physiology* Psychophysics |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Neural fine tuning during Vernier acuity training?
Next Document: Different visual search strategies in stationary and moving radial patterns.