In a series of five experiments, we investigated how amodalcompletion affects pattern recognition, and tested possible models of processes underlying completionof simple shapes. Inferences about processing models were based mainly upon the comparison of ‘same’ latencies in a simultaneous matching task. The major result of experiments 1–4 regards two conditions where a complete target had to be matched with a given stimulus region, belonging to a composite comparison pattern. Matching is faster when this stimulus region is amodally completed than when it looks like an incomplete shape. In experiment 5 we compared complete vs incomplete targets, that were either phenomenally or topographically identical to a given region ofthe comparison pattern. The failure to show any effectof target completeness suggests that phenomenal identity may be as effective as topographical identity.
