Visual Features Underlying Perceived Brightness as Revealed by Classification Images
| Autor: | Aapo Hyvärinen, Tarja Peromaa, Jussi Saarinen, Ilmari Kurki |
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| Přispěvatelé: | Helsinki Institute for Information Technology HIIT (-2009), Department of Psychology (-2009), Department of Computer Science, Department of Mathematics and Statistics, Perception Action Cognition |
| Rok vydání: | 2009 |
| Předmět: |
Brightness
Light 515 Psychology Color vision media_common.quotation_subject Illusion lcsh:Medicine Stimulus (physiology) Luminance 050105 experimental psychology Contrast Sensitivity 03 medical and health sciences 0302 clinical medicine Psychophysics Humans Visual Pathways 0501 psychology and cognitive sciences Second-order stimulus lcsh:Science Vision Ocular media_common Physics Multidisciplinary Optical Illusions Optical illusion business.industry Neuroscience/Sensory Systems lcsh:R 05 social sciences Pattern recognition Neuroscience/Experimental Psychology Neuroscience/Psychology Pattern Recognition Visual Space Perception Visual Perception lcsh:Q Artificial intelligence business Color Perception Photic Stimulation 030217 neurology & neurosurgery Research Article |
| Zdroj: | PLoS ONE, Vol 4, Iss 10, p e7432 (2009) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | Along with physical luminance, the perceived brightness is known to depend on the spatial structure of the stimulus. Often it is assumed that neural computation of the brightness is based on the analysis of luminance borders of the stimulus. However, this has not been tested directly. We introduce a new variant of the psychophysical reverse-correlation or classification image method to estimate and localize the physical features of the stimuli which correlate with the perceived brightness, using a brightness-matching task. We derive classification images for the illusory Craik-O'Brien-Cornsweet stimulus and a "real" uniform step stimulus. For both stimuli, classification images reveal a positive peak at the stimulus border, along with a negative peak at the background, but are flat at the center of the stimulus, suggesting that brightness is determined solely by the border information. Features in the perceptually completed area in the Craik-O'Brien-Cornsweet do not contribute to its brightness, nor could we see low-frequency boosting, which has been offered as an explanation for the illusion. Tuning of the classification image profiles changes remarkably little with stimulus size. This supports the idea that only certain spatial scales are used for computing the brightness of a surface. |
| Databáze: | OpenAIRE |
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