| Abstract: | Differences in processing representations of conditioned and unconditioned stimuli (CSs and UCSs) may result from either their temporal order in training (i.e., CSs precede UCSs) or the greater biological significance of UCSs. The CS- and UCS-preexposure effects were used to probe this question. These effects are similar except that context extinction between preexposure and training more readily attenuates the UCS- than the CS-preexposure effect. In Experiments 1, 2, and 5, context extinction following preexposure to the stimulus that later served as Event 1 in Event 1?→?Event 2 pairings alleviated the response deficit due to Event 1 preexposure if Event 1 was biologically significant. In Experiments 3 and 4, context extinction alleviated the response deficit due to Event 2 preexposure if Event 2 was biologically significant. Thus, biological significance and not temporal order determines how a representation will be processed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
