EBBINGHAUS ILLUSION - EFFECT OF FIGURAL SIMILARITY UPON MAGNITUDE OF ILLUSION WHEN CONTEXT ELEMENTS ARE EQUAL IN PERCEIVED SIZE

The magnitude of the Ebbinghaus illusion has been reported to be great er when test element and context elements are figurally similar as opp osed to figurally dissimilar. In the current investigation with 16 obs ervers, illusion magnitude was greater for a figurally similar configu ration even though the context elements of the figurally similar confi guration were perceived as smaller than the context elements of a figu rally dissimilar configuration. Hence, figural similarity appears to h ave a pre-potent effect in the Ebbinghaus illusion.