Perceptual organization: dimensional consistency effects, illusory contours, and perceptual and decisional influence

Open Access
Bittner, Jennifer Lee
Graduate Program:
Master of Science
Document Type:
Master Thesis
Date of Defense:
September 12, 2008
Committee Members:
  • Michael Wenger, Thesis Advisor
  • Michael J Wenger, Thesis Advisor
  • perceptual organization
  • illusory contours
  • GRT
  • general recognition theory
  • object perception
  • face perception
This thesis reports a set of experiments that test three specific hypotheses regarding perceptual organization. These are: (a) perceptual organization relies as much or more on similarity at the level of second-order characteristics than at the level of first-order physical similarity; (b) perceptual organization reflects both perceptual and decisional factors; and (c) perceptual organization of forms and faces reflect a common strategy. Previous work with both hierarchical forms and faces have shown that participants are faster to respond to a form when there is consistency among the global and local dimensions of that form. These dimensional consistency effects have been used to argue for global precedence, configurality, and other concepts relevant to perceptual organization. The current research studied hierarchical forms through the use of illusory contours. Signal detection theory (SDT) and general recognition theory (GRT) were used to assess performance for both perceptual and decisional influences. Experiment 1 was a hierarchical forms study in which three dimensions were analyzed for consistency benefit. Reaction times (RTs) showed dimensional consistency effects while response frequencies provided evidence for the presence of both perceptual and decisional influences. Experiment 2 documented the same patterns even when a decision on one of the stimulus dimensions was not required. Experiment 3 showed that analogous results could be obtained with both face-like and object-like hierarchical forms. The results in sum provide support for each of the three hypotheses and provide a foundation for extending this effort to comparisons involving face stimuli.