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On the determinants of surface brightness
1Department of General Psychology, University of Padua, Padua, Italy. scm@unipd.it
Psychonomic Bulletin & Review
|May 16, 2003
Summary
Surface brightness perception depends on the absolute luminance of the surface and its background, not just the contrast at their border. This suggests the visual system integrates luminance signals for accurate brightness estimation.
Area of Science:
- Visual perception
- Psychophysics
- Neuroscience
Background:
- Surface brightness is influenced by luminance contrast.
- Previous research suggests the visual system acts as a photometer.
- Understanding luminance integration is crucial for visual perception models.
Purpose of the Study:
- To investigate how surface luminance (S) and background luminance (B) independently affect perceived surface brightness.
- To determine the role of luminance step (deltaL) at the border in brightness perception.
- To explore the underlying neural mechanisms of luminance integration.
Main Methods:
- Two experiments were conducted involving achromatic surfaces and backgrounds.
- Participants viewed surfaces with varying luminance (S) and background luminance (B).
- The luminance step (deltaL) at the surface-background border was manipulated.
Main Results:
- Perceived surface brightness was determined by S and B, irrespective of deltaL.
- This independence held true whether the surface was adjacent to or separated from the background.
- The findings support the visual system's ability to perform photometric measurements.
Conclusions:
- Surface brightness perception relies on the integration of absolute luminance signals.
- The visual system integrates luminance information, similar to a photometer.
- A weighted-average model is proposed to explain luminance integration in brightness perception.