Associative grouping : Perceptual grouping of shapes by association Timothy

Perceptual grouping is usually defined by principles that associate distinct elements by virtue of image properties such as proximity, similarity, and occurrence within common regions. What role does learning play in forming a perceptual group? This study provides evidence that learning of shape associations leads to perceptual grouping. Participants were repeatedly exposed to pairs of unique shapes that co-occurred within a common region. The common region cue was later removed in displays composed of these shapes, while participants searched the display for two adjacent shapes of the same color. When the adjacent shapes with the same color came from the same trained groups, participants were faster at locating the color repetition than when they were composed of two shapes from different trained groups. The effects were perceptual in nature: learned pairings produced spatial distortions similar to those observed in groups defined by perceptual similarity. A residual grouping effect was observed even when shapes in the trained group switched their relative positions, but was eliminated when each shape was inverted. These results indicate that statistical co-occurrence with explicit grouping cues may form an important component of perceptual organization, determining perceived scene structure based solely on past experience.