Stoffer T H
Institut für Psychologie, Allgemeine und Experimentelle Psychologie, Ludwig-Maximilians-Universität, München, Germany.
Psychol Res. 1994;56(2):83-98. doi: 10.1007/BF00419715.
In four experiments level-specific cueing of hierarchically structured stimuli was used to test the hypothesis that valid cues can reduce the global-dominance phenomenon. Compound stimuli (Experiments 1 and 2) or simple geometric forms (Experiments 3 and 4) were presented with different SOAs after a valid, an invalid, or a neutral level-specific cue (cue validity 80%). Costs for invalid cues and benefits for valid cues were produced in all experiments. However, a reduction of the global-local RT difference to about zero was achieved only after the reduction of the abrupt visual onset accompanying stimulus presentation in Experiments 2 (with compound stimuli) and 4 (with simple geometric forms). In addition, there was no longer the typical asymmetric-interference pattern (i.e., features of the global level interfere with local identification, but not vice versa) that was one of Navon's (1977) main arguments for assuming a perceptual precedence. It is concluded that the RT that is longer for local than for global identifications is produced by the time needed to refocus visual attention intentionally from the global level, which is focussed at first unintentionally, to the local level.
