English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Contrast dependence of colour and luminance motion mechanisms in human vision

MPS-Authors
There are no MPG-Authors available
External Ressource
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Hawken, M., Gegenfurtner, K., & Chang, C. (1994). Contrast dependence of colour and luminance motion mechanisms in human vision. Nature, 367(4640), 268-270. doi:10.1038/367268a0.


Cite as: http://hdl.handle.net/21.11116/0000-0005-FD4A-C
Abstract
CONVENTIONAL views of visual perception propose a colour-blind pathway conveying motion information and a motion-blind pathway carrying colour information1,2. Recent studies show that motion perception is not always colour blind3,4, is partially dependent on attention5,6, can show considerable perceptual slowing around isoluminance7–9 and is contrast-dependent10,11. If there is a single motion pathway, receiving luminance and chromatic input, then the dependence of relative perceived velocity on relative stimulus contrast should be the same for both luminance and chromatic targets. Here we provide a distinctive characterization of the motion mechanisms using a robust velocity-matching task. A relative contrast scale allows direct comparison of the performance with luminance and chromatic targets. The results show that the perceived speed of slowly moving coloured targets at isoluminance has a steep contrast dependence. The perceived speed of slowly moving luminance targets shows a much lower contrast dependence. At high speeds the contrast dependence is low for both luminance and isoluminant stimuli, although the behaviour is unlike either of the slow mechanisms. The results suggest two independent pathways that perceive slowly moving targets: one is luminance-sensitive and the other is colour-sensitive. Fast movement is signalled via a single motion pathway that is contrast-invariant and not colour blind.