著者

濱田 治良 パラメイ ガリーナ V. エーレンシュタイン ヴァルター H.

出版者

徳島大学

雑誌

徳島大学総合科学部人間科学研究 (ISSN:09199810)

巻号頁・発行日

vol.8, pp.1-13, 2000-12-12

---

Apparent size of circles in the Delboeuf configuration wasjudged under variation of their diameters and compared to that ofcircle singletons of equivalent diameter. The primary purpose of thestudy was to investigate the effect of judgment order on the perceivedsize, i.e. starting with either inner or outer circle. In addition, wecompared the measured strength of the illusion as obtained by twodifferent methods - category rating and magnitude estimation. We foundthat the circle judged first had an assimilative effect on the apparentsize of the subsequently judged circle, with the amount of the effectbeing contingent on diameter ratio and diameter difference of theconstituent circles. Moreover, assimilation of the inner circle wasmore pronounced than that of the outer circle. The judgment-ordereffect may be accounted for by attentional mechanisms: if the outercircle is judged first, spatial span of attention is large, so that theinner circle falls in the span. Conversely, if the inner circle isjudged initially, spatial span of attention is too small to take up theouter circle. The amount of illusion was greater when judged usingmagnitude estimation than category rating, conceivably due to a coarserinternal mapping at the latter procedure.