Grouping puts figure-ground assignment in context by constraining propagation of edge assignment

Area of Science:

• Cognitive Psychology
• Computational Neuroscience
• Visual Perception

Background:

• Figure-ground organization assigns edges to shapes, typically using local cues.
• Contextual factors influencing edge assignment are less understood.
• Previous research focused on local visual cues over contextual influences.

Purpose of the Study:

• To investigate how remote contextual edges influence locally unbiased edge assignments.
• To determine the role of grouping in the propagation of edge assignment.
• To identify a new principle of grouping-constrained figure-ground assignment.

Main Methods:

• Utilized subjective reports and an objective short-term edge-matching task.
• Examined displays with grouping by common fate and collinearity (moving displays).
• Tested grouping by similarity of edge-contrast polarity and apparent occlusion (static displays).

Main Results:

• Locally unbiased edge assignments are affected by remote, locally biased contextual edges.
• Propagation of edge assignment from a biased context occurs only when edges are grouped.
• This grouping-constrained propagation applies across different grouping principles and display types.

Conclusions:

• Grouping acts as a constraint on the propagation of figural edge assignment.
• A new contextual influence on edge assignment, mediated by grouping, has been identified.
• This research elucidates a mechanistic link between grouping and figure-ground segregation processes.