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Updated: Jul 3, 2026
08:32
Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates
Published on: October 3, 2017
When figure-ground segmentation modulates brightness: the case of phantom illumination
Daniele Zavagno1, Olga Daneyko
1Dipartimento di Psicologia, Università di Milano-Bicocca, Via dell'Innovazione 10, Milan, Italy. daniele.zavagno@unimib.it
Acta Psychologica
|July 19, 2008
Summary
The phantom illumination illusion, which enhances brightness, is dependent on how figure-ground organization separates areas. Continuous gradients hinder this illusion, causing darkening instead.
Area of Science:
- Visual perception
- Psychophysics
- Computational neuroscience
Background:
- The phantom illumination illusion demonstrates brightness enhancement on dark backgrounds via luminance ramps.
- Previous research has explored factors influencing this illusion, such as inducer properties.
Purpose of the Study:
- To investigate the role of figure-ground organization in the phantom illumination illusion.
- To determine how different types of contours affect the perceived brightness of a target area.
Main Methods:
- Experiments manipulated the number and size of luminance inducers surrounding a target area.
- Participants rated the perceived brightness difference between the target and background.
- A rating task experiment tested various contour types (luminance, illusory, none, ambiguous) bordering the target area.
Main Results:
- The illusion occurred when the target area was not fully segregated by ramps; continuous gradients led to perceived darkening.
- Illusory contours, similar to luminance contours, inhibited the illusion, causing target area darkening.
- Control experiments confirmed darkening for all configurations without luminance ramps.
Conclusions:
- Figure-ground segmentation is crucial for the phantom illumination illusion and lightness perception with luminance gradients.
- The way visual elements are organized influences how we perceive brightness and illumination.
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