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Perceptual Learning

In our early experiments examining past experience effects on shape segmentation, we used displays portraying well-known objects on one side of an edge (see Segmentation and Shape & Object Perception section). Recently, we have begun to ask how much past experience with a novel shape is necessary in order for it to exert a measurable influence on perception. Surprisingly, we found that a single past experience is enough (Peterson & Lampignano, 2003; Peterson and Enns, 2005). These studies revealed a surprising degree of plasticity in object representation. We are currently conducting experiments using both behavioral and imaging methods to attempt to locate where in the visual pathway the relevant processes occur.

The top display was designed to look like a small yellow shape lying
on a larger red rectangle. The stepped edge in the top display is novel; it was
created for this experiment. Consider the two black shapes below the top
display. It is probably easy to see that the same stepped edge is repeated in
the black shape on the left. It may be a lot harder to see that the edge is also
repeated in the black shape on the right; that's because the black shape lies on
the opposite side of the edge from the yellow shape in the top display. Our
experiments reveal that a memory for where the shape lay with respect to the
edge in the yellow display is accessed even when viewers are unaware that the
edge is repeated in the black display on the right.