Apparent equivalence between perception and imagery in the production of various visual illusions

The ability of high and low imagers (as assessed by the Vividness of Visual Imagery Questionnaire) to utilize imagery in the production of a visual illusion was examined in three experiments. In Experiment 1, subjects were to imagine noninducing elements oi the Ponzo figure. In Experiment 2, subjects were asked to imagine the inducing angle of the Ponzo figure. Subjects were requested to imagine the inducing diagonals of the Hering and Wundt figures in Experiment 3. Regardless of which figure was presented, high imagers consistently reported an illusion whether it was produced by real or imagined lines. Also, the imagery-produced illusion was equivalent in magnitude to the actual illusion (when all lines are physically present). Low imagers reported an illusion only when lines were physically present. These results were interpreted in terms of Finke’s (1980) equivalence theory.