GEOMETRICAL ILLUSIONS - STUDY AND MODELING

The phenomena of geometrical illusions of extent suggest that the metr ic of a perceived held is different from the metric of a physical stim ulus. The present study investigated the Muller-Lyer and Oppel-Kundt i llusions as functions of spatial parameters of the figures, and constr ucted a neurophysiological model. The main idea of the modelling is ba sed on the uncertainty principle, according to which distortions of si ze relations of certain parts of the stimulus, socalled geometrical il lusions, are determined by processes of spatial filtering in the visua l system. Qualitative and quantitative agreement was obtained between psychophysical measurement of the strength value of the illusions and the predictions of our model.