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Abstract:
When two adjacent regions share a contour, one region is
often perceived to have a definite shape (the figure), whereas the
other region appears to be a shapeless background. Using a shape
discrimination task, Treisman and DeSchepper (1996) found negative
priming (NP) for novel shapes that had been presented as putative
grounds in a standard figure-ground display. NP was no larger for
familiar shapes than for novel shapes, raising the intriguing
possibility that memories are established (and inhibited) for the
shapes of novel grounds, despite the fact that they were never
consciously perceived as shaped entities. We replicated Treisman
and DeShepper's design with one change: no stimuli were repeated.
Also, because we expected that the figure-ground organization of
the standard displays might be ambiguous, and might therefore, be
affected by observers' viewing strategy, we separated participants
into groups based on their reported viewing strategy. NP for novel
ground shapes was evident in responses of observers who reported
looking at the comparison shape before the standard figure-ground
display, but not in responses of observers who reported looking at
the standard display before the comparison shape. We conclude that
viewing strategy affected the perceived figure/ground assignment of
the standard displays, raising questions about which region was
seen as figure versus ground. A second experiment using unambiguous
figure-ground displays tested the hypothesis that NP arises from
memories for figures rather than for grounds.
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