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A show about nothing: No-signal processes in systems factorial technology
Zachary L Howard1, Paul Garrett1, Daniel R Little2
1School of Psychology, The University of Newcastle.
Psychological Review
|September 4, 2020
Summary
Systems Factorial Technology (SFT) processing capacity assumptions are challenged. Stimulus locations impact response times even without signals, affecting capacity calculations, especially in AND tasks.
Area of Science:
- Cognitive Psychology
- Psychological Measurement
Background:
- Systems Factorial Technology (SFT) is widely used to measure processing capacity.
- SFT assumes no cognitive resources are used for stimulus locations without signals.
Purpose of the Study:
- To investigate the influence of non-signal locations on response times within the SFT framework.
- To re-evaluate processing capacity measures, particularly for conjunctive (AND) tasks.
Main Methods:
- Proposed a modified AND task requiring full identification of all target locations.
- Derived a new coefficient based on the modified task design.
- Applied the new coefficient to novel experimental data.
Main Results:
- Demonstrated that stimulus locations without signals significantly influence response times.
- Showed that this influence impacts the interpretation of processing capacity in SFT.
- Resolved a paradox where AND tasks previously showed super-capacity.
Conclusions:
- The assumption of zero resource allocation to non-signal locations in SFT is flawed.
- Previously observed differences in processing capacity between OR and AND tasks are likely artifacts.
- The proposed modification and new coefficient offer a more accurate measure of processing capacity.
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