Markov Chain Example: Transitions between Two Pictorial Attractors

Two experiments exploring similarity judgments on pairs and triplets of stimuli drawn from pictorial series are described. The stimuli are the man- woman (M-W) and gypsy-girl (Gy-Gr) pictures that slowly change from one prototype to the other as one progresses along the series. These have been used previously to demonstrate hysteresis of category judgments on ambiguous figures; the M-W series has been both modeled as a problem in neural network theory and mapped onto part of a cusp catastrophe surface. It is CONTENTS The Prototype1-Ambiguity-Prototype2 Paradigm. 428 The Man-to-Woman Experiment 430 Similarity Rating Experiment 1. 432 Stimuli 432 Subjects 432 Instructions and Procedure (Slightly Abbreviated). 432 DataAnalysis 432 Discussion435 The Gypsy-to-Girl Experiment. 436 Similarity Rating Experiment 2. 436 Stimuli 436 Subjects 436 Instructions (Slightly Abbreviated). 436 Procedure. 437 Discussion 438 Acknowledgments 443 Note. 443 References. 443 shown that the transition process is complicated with a zone of uncertainty and prevalence of bimodality in many of the pairwise similarity judgments. The dynamics are interpreted in terms of transitions between two saddlenode attractors that are themselves not a discrete pair but have some overlap in their composition.