Low-level features determine brightness in White’s and Benary’s illusions

• Published in: Vision research (Oxford) Vol. 49; no. 7; pp. 682 - 690
• Main Authors: Salmela, Viljami R., Laurinen, Pentti I.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 29.04.2009; Elsevier
• Subjects: Biological and medical sciences; Brightness; Contrast Sensitivity - physiology; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Humans; Masking; Optical Illusions - physiology; Orientation; Pattern Recognition, Visual - physiology; Perceptual Masking - physiology; Photic Stimulation - methods; Psychophysics; Sensory Thresholds - physiology; Spatial frequency; Vertebrates: nervous system and sense organs; Spatial frequency; Masking; Psychophysics; Orientation; Brightness; Vision; Stimulus brightness; Illusion
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/j.visres.2009.01.006

We masked White’s and Benary’s brightness illusions and simultaneous contrast with narrowband visual noise and measured detection thresholds and brightness. The noise was either isotropic or orientation filtered. A narrow spatial frequency tuning was found for detection and brightness for every stimulus. A narrow orientation tuning was also found: the strength of the illusions decreased (White and Benary) or increased (White) depending on the orientation of the mask. The critical borders were always of the same contrast polarity. The results suggest that the brightness in figure–ground scenes is determined by mechanisms integrating incremental and decremental borders in early visual cortices.