| Abstract: | Human participants received unsupervised exposure to difficult-to-discriminate stimuli (e.g., A and A′), created with a morphing procedure from photographs of faces, before learning a discrimination between them. Experiments 1 and 2 demonstrated that prior exposure enhanced later discrimination and that intermixed exposure (A, A′, A, A′...) resulted in better subsequent discrimination than blocked exposure (B, B, ...B′, B′...). Experiments 3 and 4 showed that simultaneous exposure to 2 similar stimuli facilitated the later acquisition of both a simultaneous and a successive discrimination, and this effect was observed even though simultaneous exposure to 2 stimuli fostered the development of an excitatory association between them (Experiment 5). The findings of Experiments 1 and 2 revealed a perceptual learning effect with pictures of faces, and the findings of Experiments 3-5 are difficult to reconcile with associative analyses of perceptual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
