• Media type: E-Article
  • Title: Limited Capacity for Contour Curvature in Iconic Memory
  • Contributor: Sakai, Koji
  • Published: SAGE Publications, 2006
  • Published in: Perceptual and Motor Skills, 102 (2006) 3, Seite 611-631
  • Language: English
  • DOI: 10.2466/pms.102.3.611-631
  • ISSN: 0031-5125; 1558-688X
  • Origination:
  • Footnote:
  • Description: We measured the difference threshold for contour curvature in iconic memory by using the cued discrimination method. The study stimulus consisting of 2 to 6 curved contours was briefly presented in the fovea, followed by two lines as cues. Subjects discriminated the curvature of two cued curves. The cue delays were 0 msec. and 300 msec. in Exps. 1 and 2, respectively, and 50 msec. before the study offset in Exp. 3. Analysis of data from Exps. 1 and 2 showed that the Weber fraction rose monotonically with the increase in set size. Clear set-size effects indicate that iconic memory has a limited capacity. Moreover, clear set-size effect in Exp. 3 indicates that perception itself has a limited capacity. Larger set-size effects in Exp. 1 than in Exp. 3 suggest that iconic memory after perceptual process has limited capacity. These properties of iconic memory at threshold level are contradictory to the traditional view that iconic memory has a high capacity both at suprathreshold and categorical levels.