Amodal completion of partly occluded figures: Effect of contour orientation Cover Image

Amodalno kompletiranje poluzaklonjenih figura: Efekat orijentacije konture
Amodal completion of partly occluded figures: Effect of contour orientation

Author(s): Slobodan Marković, Vasilije Gvozdenović
Subject(s): Cognitive Psychology, Experimental Pschology
Published by: Društvo psihologa Srbije
Keywords: amodal completion; form; orientation; priming;

Summary/Abstract: In present study the temporal dimension of amodal completion in visual occlusion was investigated. We supposed that the visual system prefers to complete normally (vertically-horizontally) oriented contours than the oblique ones. Using the prime-matching paradigm we investigated the strength of amodal primes effects on processing speed of relating test figures. Both, prime and test stimuli were presented in normal and oblique (45o ) orientations. The primes were pairs of identical figures: CC (truncked squares), SS (hexagons) and AA (amodal patterns: circle occludes either amodal C or amodal S). Temporal distribution of stimuli: prime 400ms, ISIs 20ms and test figures until response. Test figures were the “same” pairs, CC and SS, and the “different” pairs, SC and CS. Each “same” test figures had its identical prime (CC => CC or SS => SS) and its amodal prime (AA => CC and AA => SS). The subjects were asked to answer wether the figures in test stimuli were same or different. The “same” RTs were analysed. The effect of amodal prime was systematically weaker (longer RT) than the effect of identical primes. Orientation was not significant factor. The significant partial interaction prime x orientation was obtained for C test figures: the effect of amodal prime was closer to effect of identical prime when the contour was normally oriented. In the case of S test figures the interaction was not obtained. We concluded that the more symmetric test figure (S) was resistent to the prime effect.

  • Issue Year: 36/2003
  • Issue No: 3
  • Page Range: 271-288
  • Page Count: 18
  • Language: Serbian