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Updated: May 24, 2026
07:13
A Two-interval Forced-choice Task for Multisensory Comparisons
Published on: November 9, 2018
New laws of simultaneous contrast?
1Institut für Psychologie, Universität Kiel, Olshausenstraße 62, 24118 Kiel, Germany. vekroll@psychologie.uni-kiel.de
Seeing and Perceiving
|February 29, 2012
Summary
The direction of simultaneous contrast is determined by the difference between target and surround colors, not their complementary colors. The effect
Area of Science:
- Color perception
- Visual neuroscience
- Psychophysics
Background:
- The traditional understanding of simultaneous contrast suggests its direction is complementary to the surround color (complementarity law).
- Kirschmann's fourth law posits that the size of the simultaneous contrast effect is constant.
- Existing theories often overlook confounding factors like temporal von Kries adaptation.
Purpose of the Study:
- To propose a new 'direction hypothesis' for simultaneous contrast in three-dimensional color space.
- To challenge the established complementarity law and Kirschmann's fourth law.
- To explain the historical adherence to these laws by accounting for confounding factors.
Main Methods:
- Analysis of diverse and seemingly unrelated lines of evidence.
- Development of a theoretical framework for simultaneous contrast.
- Re-interpretation of empirical data considering temporal von Kries adaptation.
Main Results:
- The direction of simultaneous contrast is dictated by the difference vector between target and surround.
- The size of the simultaneous contrast effect is either constant or decreases with increasing target-surround difference.
- The apparent validity of previous laws is attributed to unaddressed confounding factors, primarily temporal adaptation.
Conclusions:
- The 'direction hypothesis' offers a more accurate model of simultaneous contrast in 3D color space.
- The complementarity law and Kirschmann's fourth law are shown to be limited or incorrect under specific conditions.
- Temporal von Kries adaptation is a critical factor influencing the perception of simultaneous contrast.
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