Inhibitory competition in figure-ground perception: context and convexity

Area of Science:

• Visual Perception
• Cognitive Psychology
• Computational Neuroscience

Background:

• Convexity is a known cue for figure-ground segregation.
• Previous research suggests a bias towards perceiving figures on the convex side of an edge.

Purpose of the Study:

• To investigate how the number of alternating convex and concave regions affects the convexity cue in figure-ground perception.
• To determine the role of region homogeneity in these context effects.
• To refine models of figure-ground segregation.

Main Methods:

• Four experiments were conducted manipulating the number of edges and the homogeneity of alternating regions.
• Participants' figure-ground perception was assessed under various visual conditions.
• Statistical analyses were used to evaluate the significance of observed biases.

Main Results:

• A single edge shows only a weak convexity bias.
• The bias for convexity increases with more alternating regions when concave regions are homogeneous.
• Homogeneity of convex regions is irrelevant; homogeneity of concave regions is crucial.
• Homogeneity alone is insufficient; a cue favoring intervening regions as figures is necessary.

Conclusions:

• Figure-ground perception is influenced by the interplay of shape and region properties.
• Homogeneity of concave regions enhances the figure-ground segregation bias towards convexity.
• A model where shape properties compete and homogeneity reduces competitive strength explains the findings.