A syntactic complexity effect with visual patterns: evidence for the syntactic nature of the memory representation

In a series of 3 experiments, participants learned visual patterns that contained the same number of visual features but varied in the complexity of the interrelations among the features. The results indicate a large and orderly effect of the pattern's syntactic complexity on recognition speed. Evidence is provided that this effect was not due to physical characteristics, target-foil similarity, speed-accuracy trade-off, or level of pattern learning. A multiple-encoding explanation of the effect is described. According to this framework, there is an initial, automatically generated encoding of the pattern as a short-term pictorial representation that becomes the basis for the construction of a second syntactic-propositional encoding. In this model, the participant's "sense of familiarity" for a particular stimulus is associated only with the syntactic-propositional encoding.