| Curvature coding is tuned for motion direction. | |
| | |
MedLine Citation:
|
PMID: 20377295 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
We have investigated the global and local motion tuning properties of curvature coding mechanisms using two shape after-effects believed to be mediated by curvature-sensitive mechanisms: the shape-frequency after-effect, or SFAE, and the shape-amplitude after-effect, or SAAE. The SFAE and SAAE are the phenomena in which adaptation to a sine-wave-shaped contour causes a shift in respectively the apparent shape-frequency and apparent shape-amplitude of a test contour in a direction away from that of the adapting stimulus. In the global motion condition the sinusoidal-shaped contours were made to drift within a fixed stimulus window in the direction of their axis of modulation. In the local motion condition the contour was constructed from a string of Gabors, and their carriers but not envelopes moved. We investigated selectivity to motion direction by using adaptor and test contours that moved either in the same or opposite directions. We found that in the global motion condition both the SFAE and SAAE showed selectivity to motion direction, and that for the same-motion-direction condition, both after-effects increased with shape temporal frequency. We then examined the effect of luminance spatial frequency and luminance temporal frequency on global motion direction selectivity. Luminance temporal frequency accounted for some of the increase in after-effect magnitude with shape temporal frequency, but shape temporal frequency also contributed. The local motion after-effects on the other hand were neither selective to motion direction nor increased with luminance temporal frequency. Taken together, the results are best understood by supposing that curvature is encoded by mechanisms that are selective to motion direction and that the directional selectivity best manifests itself psychophysically when there is sufficient spatio-temporal coverage of the stimulus to stimulate the full array of potentially responsive curvature-coding mechanisms. |
| | |
Authors:
|
Elena Gheorghiu; Frederick Kingdom; Rickul Varshney |
Related Documents
:
|
3617515 - Perception of illusory occlusion in apparent motion. 8482965 - Coding of movement direction and amplitude in parkinson's disease: are they differentia... 16638175 - Temporal interactions in direction-selective complex cells of area 18 and the posterome... 20028135 - Air-stable operation of transparent, colloidal quantum dot based leds with a unipolar d... 2331345 - Voluntary control of submaximal grip strength. 17165115 - Friction dynamics of trocars. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-03-30 |
Journal Detail:
|
Title: Journal of vision Volume: 10 ISSN: 1534-7362 ISO Abbreviation: J Vis Publication Date: 2010 |
Date Detail:
|
Created Date: 2010-04-09 Completed Date: 2010-07-12 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 101147197 Medline TA: J Vis Country: United States |
Other Details:
|
Languages: eng Pagination: 18.1-19 Citation Subset: IM |
Affiliation:
|
Laboratory of Experimental Psychology, University of Leuven, Leuven, Belgium. elena.gheorghiu@psy.kuleuven.be |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adaptation, Physiological
/
physiology Contrast Sensitivity / physiology Feedback Figural Aftereffect / physiology* Form Perception / physiology* Humans Lighting Models, Neurological* Motion Perception / physiology* Photic Stimulation / methods Psychophysics |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Bayesian adaptive estimation of the contrast sensitivity function: the quick CSF method.
Next Document: Robustness of the retinotopic attentional trace after eye movements.