The role of visual awareness in processing of global structure: Evidence from the perceptual organization of hierarchical patterns

We examined whether the perceptual organization of hierarchical structure, and specifically, the integration of local elements into a global shape, requires visual awareness, using a masked priming paradigm, sandwich masking to render the prime invisible, and two types of primes, many-element hierarchical patterns composed of many relatively small elements (Experiment 1) and few-element hierarchical patterns composed of a few relatively large elements (Experiment 2). A significant response priming of the local elements of many-element patterns was observed for invisible primes, whereas a significant response priming of the global shape was found only for the visible primes. For the few-element patterns, only significant response priming of the local elements was observed, as expected, for both visible and invisible primes. Our results suggest that local elements are represented in the absence of visual awareness, regardless of their number and relative size. Visual awareness, however, can be essential for grouping local elements into a global shape. The critical role of awareness in deriving global structure implies that global perception, which characterizes much of our early perception of objects and scenes, is likely to depend on visual awareness.