Print Email Facebook Twitter Apparent motion produced by temporally modulated brightness contrast and assimilation Title Apparent motion produced by temporally modulated brightness contrast and assimilation Author Kooi, F.L. TNO Technische Menskunde Publication year 1995 Abstract When regions containing a counterphasing sine-wave grating are presented side by side and in spatial and temporal quadrature phase, a transparent perception of motion results. This occurs even though none of the stimulus parts is moving. The two percepts of motion in these displays are in opposite directions, one analogous to brightness contrast, the other to brightness assimilation. If the regions are separated by a gap, the contrast and assimilation motions remain visible for separations up to 0.5 and 1 period, respectively. Both motions occur at temporal frequencies from 1 to 16 Hz. The perceived motion analogous to brightness assimilation is easily modeled with elongated receptive fields that integrate flux along the long axis, such as simple cells. The perceived motion analogous to brightness contrast can be accounted for by receptive fields that subtract the flux in one region from the flux in another region. Examples are center–surround subunits such as are found in the elaborated Reichart model [W. Reichardt, in Sensory Communication, W. A. Rosenblith, ed. (MIT Press, Cambridge, Mass., 1961), pp. 303–317; J. P. H. van Santen and G. Sperling, J. Opt. Soc. Am. A 2, 300–321 (1985)]. The dual perceived motion suggests that more than one kind of motion channel (distinguished by the two-dimensional receptive field of the front-end filter) is present in the human visual system. Subject VisionComputer simulationDiffraction gratingsFourier opticsFrequenciesLuminescencePhysiologySpectrum analysisBrightness assimilationBrightness contrastGap sizeMotion perceptionPhysiological receptive fieldsSine wave gratingsStimuliVisionarticlecontrast sensitivityhumanlightmovement perceptionphysiologyContrast SensitivityHumanLightMotion Perception To reference this document use: http://resolver.tudelft.nl/uuid:dcacf201-46f1-4073-8f9d-967843b33db7 TNO identifier 12914 Source Journal of the Optical Society of America A, 12 (2), 234-240 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.