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Detectability as a function of target location: effects of spatial configuration
R Efron1, E W Yund, D R Nichols
1Neurophysiology-Biophysics Research Laboratory, Veterans Administration Medical Center, Martinez, California 94553.
Brain and Cognition
|January 1, 1990
Summary
This study investigated visual search processes. Results suggest that the rapid scanning of visual information is nonattentional, not driven by focused attention, challenging previous theories.
Area of Science:
- Cognitive Psychology
- Neuroscience
- Visual Perception
Background:
- Visual search tasks reveal a "detectability gradient" where target detection varies with spatial location.
- Target detectability decreases as the number of nontarget patterns increases.
- Previous findings suggest a serial processing scan of a degrading neural representation of visual stimuli.
Purpose of the Study:
- To determine if the visual search scan is attentional or perceptual.
- To test the hypothesis of an attentional scan by examining "group processing" effects.
Main Methods:
- Subjects performed a visual search task with target and nontarget patterns presented in spatially segregated groups.
- Target detectability was measured across different spatial configurations.
Main Results:
- No evidence of "group processing" was observed, where detection performance typically clusters within groups.
- Target detectability did not show the expected pattern for an attentional scan.
Conclusions:
- The findings do not support an attentional scan hypothesis for visual search.
- Results are consistent with a nonattentional scan mechanism underlying visual information processing.