Summation of Target and Mask Metacontrast Stimuli
- 1 April 1984
- journal article
- Published by SAGE Publications in Perception
- Vol. 13 (2), 183-192
- https://doi.org/10.1068/p130183
Abstract
Three experiments are reported; they show the following: (i) Metacontrast occurs at high photopic conditions (250 cd m−2); at this luminance the function peaks at stimulus asynchronies of ∼40 ms (compared with 100 ms at lower luminances). (ii) The strength of metacontrast is contrast-independent, down to contrast very near detection threshold. (iii) Detection thresholds for the combined target and mask presentation are lower than those for the mask alone, implying summation between target and mask. Summation is greatest at the same asynchronies which yield maximum metacontrast masking. The experiments are taken as evidence in favour of a fusion explanation for metacontrast. An argument is made which implicates temporally units of the motion detection system as being instrumental in the fusion process.Keywords
This publication has 28 references indexed in Scilit:
- Contrast sensitivity at high velocitiesVision Research, 1982
- Visual hyperacuity: spatiotemporal interpolation in human visionProceedings of the Royal Society of London. B. Biological Sciences, 1981
- Temporal summation of moving images by the human visual systemProceedings of the Royal Society of London. B. Biological Sciences, 1981
- Motion smearNature, 1980
- Sensitivity to spatial phaseVision Research, 1980
- Perceptual delay: A consequence of metacontrast and apparent motion.Journal of Experimental Psychology: Human Perception and Performance, 1980
- Implications of sustained and transient channels for theories of visual pattern masking, saccadic suppression, and information processing.Psychological Review, 1976
- The mechanism of directionally selective units in rabbit's retina.The Journal of Physiology, 1965
- MetacontrastJournal of the Optical Society of America, 1953
- METACONTRASTOptometry and Vision Science, 1952