Memory for objects and parts

Performance on whole comparisons of two whole objects was compared to that for partial comparisons of a whole object and a part. In particular, same-different comparisons were measured for sequential displays of two-dimensional line figures. The comparisons were analogous to those in the word priority paradigm (Johnson, 1975). The whole comparisons were found to be more accurate and faster than the partial comparisons. This whole advantage was also found for accuracy using a two-alternative forced-choice procedure. This effect was found for brief displays of a single object and for longer duration displays of two objects. It was also found for three different sets of line figures. In contrast, the whole advantage was not found for unconnected figures. These findings were interpreted in the context of hierarchical representations of objects and parts.