Form and texture in hierarchically constructed patterns.

Perceived organization of hierarchically constructed patterns was investigated through similarity judgments and a verbal description task. The number of elements and their sizes relative to the configuration were varied in a series of five experiments. The results show that in patterns composed of a few relatively large elements, the elements are perceived as individual parts of the overall form and are perceptually salient. Increasing the number of elements and/or decreasing their size results in a perceived unified form associated with texture, representing the structural properties of the elements as a group. In the latter case, the perceptual salience of the individual element decreases and the global form (or sometimes the texture) dominates perception. These findings suggest that the perceptual levels arising from global configuration of local elements may not correspond directly to these two geometrical levels in the stimulus domain as much previous work on "global versus local" processing has assumed. Rather, the mapping of the two independent geometrical levels into meaningful perceptual levels depends critically on the number and relative size of the elements, thus changing the perceived organization of the whole pattern.