ILLUSIONS IN CONCRETE SITUATIONS .2. EXPERIMENTAL STUDIES OF POGGENDORFF ILLUSION

Experimental consideration is given to the problem of whether or not the spatial distortions evident in abstract illusion figures remain apparent when such figures are embodied within patterns which represent real-life scenes and concrete objects. Materials are prepared specially to allow comparison of the magnitudes of abstract versions of the Poggendorff illusion with those of otherwise similar but concrete forms. The results of two experiments suggest that the characteristic distortion seen in this figure remains present, unchanged in direction and undiminished in extent, irrespective of any concrete connotations which the illusory spatial element may be given. The conclusion drawn is that the arguments invoking the lack of relevance of illusions to the wider issues of visual perception are based upon mistaken evidence. © 1969 Walter de Gruyter. All rights reserved.