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How much processing do nonattended stimuli receive? Apparently very little, but
C W Eriksen1, J M Webb, L R Fournier
1Department of Psychology, University of Illinois, Urbana-Champaign 61820.
Perception & Psychophysics
|May 1, 1990
Summary
This study reveals that attention processing speed depends on stimulus type. Automatic processing doesn't prevent re-processing when attention is directed, impacting reaction times (RTs) for target identification.
Area of Science:
- Cognitive Psychology
- Human Information Processing
- Visual Attention
Background:
- The early versus late selection debate in attention models remains a key area of research.
- Understanding how attention influences stimulus processing is crucial for cognitive models.
Purpose of the Study:
- To investigate the early versus late selection issue in attention using a novel methodology.
- To examine the impact of stimulus preview time on reaction times (RTs) for target identification.
Main Methods:
- A new methodology involved directing attention to one location in a visual display while changing a stimulus at another.
- Preview time of the original stimulus was manipulated before attention was directed to the changed stimulus.
- Subjects performed a timed letter discrimination task to measure RTs.
Main Results:
- Reaction times to a new target were unaffected by preview time when the original stimulus was neutral (noise).
- Significant effects on RTs were observed at 83 msec preview time when the original stimulus changed to the alternative target.
- Precuing shortened preview times, indicating faster attentional deployment.
Conclusions:
- Results suggest two distinct information-processing systems: automatic and attentional.
- Attentional engagement reinitiates processing, even for automatically processed stimuli.
- This challenges simple early selection models by showing attentional effects on already processed information.