Time course of comparison

Robert L. Goldstone, Douglas L. Medin
1994 Journal of Experimental Psychology. Learning, Memory and Cognition  
Similarity as interactive activation and mapping (SIAM), a model of the dynamic course of similarity comparisons, is presented. According to SIAM, when structured scenes are compared, the parts of one scene must be aligned, or placed in correspondence, with the parts from the other scene. Emerging correspondences influence each other in a manner such that, with sufficient time, the strongest correspondences are those that are globally consistent with other correspondences. Relative to globally
more » ... nconsistent feature matches, globally consistent feature matches influence similarity more when greater amounts of time are given for a comparison. A common underlying process model of scene alignment accounts for commonalities between different task conditions. Differences between task conditions are accounted for by principled parametric variation within the model. PDF Image: PDF Full Text Database: PsycARTICLES . Electronic mail may be sent to rgoldsto@ucs.indiana.edu. The similarity of some situations is immediately apparent. The basis for the similarity of the The Odyssey and The Iliad is clear at once (both are Greek epic poems). Recognizing the commonalities between The Odyssey and The Wizard of Oz, however, is a relatively slow process. The time course of similarity assessments provides a useful tool for investigating the process by which entities are compared. These time course data inform questions concerning how entities are mentally represented and have important implications for theories of similarity. In this article, we present a model of similarity comparison that makes specific time course predictions, which were tested in three experiments. Before turning to that model, we first outline the need for a consideration of similarity processes. An alternative strategy to ignoring task differences (or treating different tasks as unrelated) is to develop a single unified model of similarity that accounts for both similarities and differences among tasks. Although the argument against a single, generic comparison process is fairly compelling, developing such a model may play an extremely useful function in linking these various measures of similarity. Indeed, we have been surprised at just how successful a model using a single mechanism to predict both similarity judgments and samedifferent reaction times can be. The key idea is that comparison processes unfold over time and same-different tasks typically involve shorter time periods than do similarity ratings. The model we present in the next section provides an account for the strong correlation between similarity measures and also their systematic dissociation. According to this model, different measures of similarity are correlated to the extent that the tasks all require a process that places the parts of the compared entities into alignment. Dissociations between similarity measures are accounted for by variations in task-relevant parameters. In specific, different tasks can be modeled by performing different amounts of processing. Tasks that are performed quickly by subjects are modeled by allowing fewer processing cycles in a computational model.
doi:10.1037//0278-7393.20.1.29 fatcat:ujfgnwnsrbgavfolrk72zp7ohu