Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/20527
Appears in Collections:Psychology Journal Articles
Peer Review Status: Refereed
Title: Luminance-contrast properties of contour-shape processing revealed through the shape-frequency after-effect
Authors: Gheorghiu, Elena
Kingdom, Frederick A A
Contact Email: elena.gheorghiu@stir.ac.uk
Keywords: Contour-shape
Adaptation
Shape-frequency after-effect
Contrast-polarity
Blur
Contrast
Issue Date: Oct-2006
Publisher: Elsevier
Citation: Gheorghiu E & Kingdom FAA (2006) Luminance-contrast properties of contour-shape processing revealed through the shape-frequency after-effect, Vision Research, 46 (21), pp. 3603-3615.
Abstract: We investigated the first-order inputs to contour-shape mechanisms using the shape-frequency after-effect (SFAE), in which adaptation to a sinusoidally modulated contour causes a shift in the apparent shape-frequency of a test contour in a direction away from that of the adapting stimulus [Kingdom F. A. A., & Prins N. (2005a). Different mechanisms encode the shapes of contours and contour-textures. Journal of Vision 5(8), 463, (Abstract)]. We measured SFAEs for adapting and test contours (and edges) that differed in the contrast-polarity, scale (or blur) and magnitude of luminance contrast. The rationale was that if the SFAE was found to be reduced when adaptor and test differed along a particular dimension of luminance contrast, contour-shape mechanisms must be tuned to that dimension. Our results reveal that SFAEs manifest (i) a degree of selectivity to luminance contrast polarity for both even-symmetric (contours only) and odd-symmetric (both contours and edges) luminance profiles; (ii) a degree of selectivity to luminance scale (or blur); (iii) higher selectivity to fine compared to coarse scale for broadband edges (iv) a small preference for equal-in-contrast adaptors and tests. These results suggest that contour shapes are not encoded in the form of a sparse, cartoon-like sketch, as might be presumed by local energy (i.e. non-phase-selective) or form-cue invariant models, but instead in a form that is relatively ‘feature-rich.'
Type: Journal Article
URI: http://hdl.handle.net/1893/20527
DOI Link: http://dx.doi.org/10.1016/j.visres.2006.04.021
Rights: The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.
Affiliation: Psychology
McGill University

Files in This Item:
File Description SizeFormat 
Gheorghiu and Kingdom (2006).pdf354.81 kBAdobe PDFUnder Embargo until 31/12/2999     Request a copy

Note: If any of the files in this item are currently embargoed, you can request a copy directly from the author by clicking the padlock icon above. However, this facility is dependant on the depositor still being contactable at their original email address.

This item is protected by original copyright



Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

If you believe that any material held in STORRE infringes copyright, please contact library@stir.ac.uk providing details and we will remove the Work from public display in STORRE and investigate your claim.