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Visual Search and Dual Tasks Reveal Two Distinct Attentional Resources

VanRullen, Rufin and Reddy, Lavanya and Koch, Christof (2004) Visual Search and Dual Tasks Reveal Two Distinct Attentional Resources. Journal of Cognitive Neuroscience, 16 (1). pp. 4-14. ISSN 0898-929X.

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Most theories of visual processing assume that a target will “pop out” from an array of distractors (“parallel” visual search, e.g., color or orientation discrimination) if targets and distractors can be discriminated without attention. When the discrimination requires attention (e.g., rotated L vs. T or red-green vs. green-red bisected disks), “serial” examination is needed in visual search. Attentional requirements are also frequently assessed by measuring interference from a concurrently performed attentionally demanding task. It is commonly believed that attention acts equivalently in dual-task and visual search paradigms, based on the implicit assumption that visual attentional requirements can be defined along a single dimension. Here we show that there is no such equivalence: We report on targets that do not trigger pop-out, even though they can be discriminated from distractors with attention occupied elsewhere (natural scenes, color-orientation conjunctions); conversely, we show that certain targets that pop out among distractors need undivided attention to be effectively discriminated from distractors when presented in isolation (rotated L vs. +, depth-rotated cubes). In other words, visual search and dual-task performance reveal attentional resources along two independent dimensions. We suggest an interpretation of these results in terms of neuronal selectivities and receptive field size effects.

Item Type:Article
Related URLs:
URLURL TypeDescription
VanRullen, Rufin0000-0002-3611-7716
Koch, Christof0000-0001-6482-8067
Additional Information:© 2004 Massachusetts Institute of Technology. Posted Online March 13, 2006. This research was supported by grants from the NSF sponsored Engineering research Center at Caltech, the National Institutes of Health, the Keck Foundation, and the McDonnell Foundation. The authors thank FeiFei Li and Pietro Perona for helpful discussions, and Francis Crick, Anne Treisman, Achim Braun, and Leila Reddy for critical comments on the manuscript.
Group:Koch Laboratory (KLAB)
Funding AgencyGrant Number
Center for Neuromorphic Systems Engineering, CaltechUNSPECIFIED
W. M. Keck FoundationUNSPECIFIED
James S. McDonnell FoundationUNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:20130816-103234995
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Official Citation:Visual Search and Dual Tasks Reveal Two Distinct Attentional Resources Rufin VanRullen, Lavanya Reddy, and Christof Koch Journal of Cognitive Neuroscience 2004 16:1, 4-14
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:40536
Deposited By: KLAB Import
Deposited On:12 Jan 2008 00:03
Last Modified:03 Oct 2019 05:14

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