Procedural differences in processing intact and degraded stimuli.
In three experiments, the extent to which the processing of a visual stimulus profits from equal processing demands of a preceding stimulus was examined. Subjects identified two subsequently presented digits (S1 and S2) that were either intact or degraded by noise, yielding four combinations of stimulus quality. In Experiments 1 and 2, S1 and S2 differed with respect to the values of the digits, so that stimulus quality was the only dimension of possible agreement. The results revealed a faster response to S2 when the stimulus pairs were homogeneous (both intact or both degraded stimuli) than when they were not homogeneous (degraded-intact pairs and intact-degraded pairs, respectively). The occurrence of equal values of S1 and S2 (Experiment 3) tended to magnify this homogeneous-stimulus effect, but was not a prerequisite for its occurrence. Relative to conditions considered to be neutral, the homogeneous-stimulus effect proved to be due to deviant behavior following the processing of a degraded S1. The suggestion that this reflects the involvement of controlled processing is discussed.
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Department of Psychology, Vrije Universiteit, Amsterdam, The Netherlands.
D001307:Auditory Perception; D004192:Discrimination, Psychological; D005260:Female; D005556:Form Perception; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011930:Reaction Time; D012438:Saccades; D013647:Task Performance and Analysis; D014796:Visual Perception