摘要：In the Ebbinghaus illusion,the size of a figure is overestimated when it is surrounded by smaller figures and underestimated when it is surrounded by larger figures.The present study examined whether the illusion is also influenced by the additional inner parts of the inducing context figures.A central square was surrounded by two types of context figures: larger and smaller figures.Each type of context figures had either square or circular shape,or was absent from the display.When both larger and smaller figures were presented,smaller figures were added inside the large ones.Data was gathered with the adjustment method.When the Ebbinghaus display was presented to the left of the probe figure,the perceived size of the central square was larger than in conditions with the display presented to the right of the probe figure.Larger context figures alone induced size underestimation and smaller figures induced size overestimation.A clear similarity effect was observed – squares induced larger illusion than circles,so the size contrast effect was most likely the predominant factor of the illusion.When the smaller context figures were added to the larger ones,the underestimation of the size of the central figure was reduced.Although the effects of the larger and smaller context figures were not completely additive,the results showed that the visual system takes into consideration both similar and dissimilar context figures when making size comparisons.
其他摘要：Pri Ebbinghausovi iluziji pride do precenjevanja velikosti osrednjega lika,kadar je obdan z manjšimi liki,in do podcenjevanja njegove velikosti,kadar je obdan z večjimi liki.V raziskavi smo ugotavljali,ali na iluzijo vplivajo tudi dodatni liki znotraj kontekstnih likov.Osrednji kvadrat smo obdali z dvema vrstama likov,tj.z večjimi in manjšimi liki,ki so bili bodisi kvadrati bodisi krogi bodisi niso bili predvajani.V pogojih,ko so bili predvajani tako večji kot manjši liki,so bili slednji dodani v notranjost večjih likov.Za zbiranje podatkov smo uporabili metodo prilagajanja.Rezultati so pokazali,da je bila zaznana velikost osrednjega kvadrata večja v primerih,ko je bil Ebbinghausov prikaz predvajan na levi strani zaslona,kot takrat,ko je bil predvajan na desni strani.Ko so bili predvajani samo večji kontekstni liki,je bila velikost osrednjega lika pričakovano podcenjena,ko so bili predvajani samo manjši kontekstni liki,pa precenjena.Jasno je bil izražen učinek podobnosti – kvadrati so povzročili večjo iluzijo kot krogi – kar kaže,da je na pojav iluzije vplival predvsem učinek kontrasta velikosti.Ko so bili večjim likom dodani manjši,se je podcenjevanje velikosti osrednjega kvadrata zmanjšalo.Čeprav učinkovanje večjih in manjših kontekstnih likov ni bilo povsem aditivno,so rezultati pokazali,da vidni sistem pri presojanju velikosti nekega lika upošteva tako podobne kot različne kontekstne like.
关键词：Ebbinghaus illusion;visual perception;size perception;contextual effects;method of adjustment;illusions
