title: Perceiving the intensity of light.
abstract: The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands, Craik-O'Brien-Cornsweet edge effects, and the Chubb-Sperling-Solomon illusion have all generated much interest but no generally accepted explanation. The authors review evidence that the full range of this perceptual phenomenology can be rationalized in terms of an empirical theory of vision. The implication of these observations is that perceptions of lightness and brightness are generated according to the probability distributions of the possible sources of luminance values in stimuli that are inevitably ambiguous.
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA. purves@neuro.duke.edu
authors.forename: Dale
authors.initials: D
authors.lastname: Purves
authors.forename: S Mark
authors.initials: SM
authors.lastname: Williams
authors.forename: Surajit
authors.initials: S
authors.lastname: Nundy
authors.forename: R Beau
authors.initials: RB
authors.lastname: Lotto
mesh_terms: D001288:Attention / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology; D006801:Humans; D008027:Light; D009903:Optical Illusions / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D011337:Probability Learning; D011603:Psychophysiology; D012165:Retinal Ganglion Cells / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology