Differences in top-down influences on the reversal rate of different categories of reversible figures

Understanding the mechanisms underlying the multistability of reversible fi gures may provide valuable insights into the normal functioning of our visu al system. The proposed factors that control the perceptual alternations of reversible figures can be classified into bottom-up and top-down processes . In the present study, we report differences in top-down effects on the re versal rate depending on whether a structural perspective (Necker cube, Sch roder staircase) or a meaningful content (duck/rabbit figure, chef/dog figu re) is subject to the reversal phenomenon. In order to activate top-down me chanisms explicitly the subjects had the instruction to bring the reversal rate under voluntary control. The results indicated that both slowing down and speeding up the rate of alternations was more effective for the content -reversal figures (duck/rabbit, chef/dog) than for the rather abstract pers pective-reversal figures (Necker cube, Schroder staircase). In order to inv estigate the effect of meaningfulness in figure/ground reversals, the effec t of the same instructional variable was also determined for Rubin's vase/f aces and the Maltese cross. The results showed a similar tendency as in the case of the comparison between perspective reversals and content reversals . Possible cognitive processes that may play a, role in top-down influences on figure reversal and theoretical implications of these findings for the interaction of bottom-up and top-down processes are discussed.