Effects of spatially directed attention on visual encoding.
The purpose in this study was to distinguish among possible mechanisms by which focused attention facilitates visual perceptual processing in a cued discrimination task. In two experiments, subjects verified the presence of an X in masked, briefly presented, four-letter arrays. On most trials, subjects were precued to the location of the stimulus array (valid-cue condition); however, sometimes a nonstimulus location was cued (invalid-cue condition). The exposure duration of the stimulus array was varied. In Experiment 1, there was a large effect of cue condition on hit probability, but no effect of cue condition on false alarm probability. In Experiment 2, there was a large effect of cue condition on d'. In both experiments, the stimulus duration needed to reach any given performance level was greater by a constant factor for stimuli in the invalid-cue than it was in the valid-cue condition. This suggests that visual information is acquired (or utilized) more rapidly from attended than from unattended locations.
Reinitz
M T
MT
Department of Psychology, Southeastern Louisiana University, Hammond 70402.
D000328:Adult; D001288:Attention; D003463:Cues; D004193:Discrimination Learning; D005556:Form Perception; D006801:Humans; D009949:Orientation; D010364:Pattern Recognition, Visual