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Withdrawing attention at little or no cost: Detection and discrimination tasks

Braun, Jochen and Julesz, Bela (1998) Withdrawing attention at little or no cost: Detection and discrimination tasks. Perception and Psychophysics, 60 (1). pp. 1-23. ISSN 0031-5117. doi:10.3758/BF03211915.

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We used a concurrent-task paradigm to investigate the attentional cost of simple visual tasks. As in earlier studies, we found that detecting a unique orientation in an array of oriented elements (“pop-out”) carries little or no attentional cost. Surprisingly, this is true at all levels of performance and holds even when pop-out is barely discriminable. We discuss this finding in the context of our previous report that the attentional cost of stimulus detection is strongly influenced by the presence and nature of other stimuli in the display (Braun, 1994b). For discrimination tasks, we obtained a similarly mixed outcome: Discrimination of letter shape carried a high attentional cost whereas discrimination of color and orientation did not. Taken together, these findings lead us to modify our earlier position on the attentional costs of detection and discrimination tasks (Sagi & Julesz, 1985). We now believe that observers enjoy a significant degree of “ambient” visual awareness outside the focus of attention, permitting them to both detect and discriminate certain visual information. We hypothesize that the information in question is selected by a competition for saliency at the level of early vision.

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Additional Information:Copyright 1998 Psychonomic Society, Inc.. (Manuscript received November 21, 1995; revision accepted for publication January 7, 1997.) We thank Nancy Kanwisher, Christof Koch, and Pietro Perona for discussions, and Leslie Brothers, John Duncan, Charles Folk, Christof Nothdurft, Jeremy Wolfe, and Steven Yantis for commenting on various versions of the manuscript. In addition, J.B. wishes to thank Nancy Kanwisher for her encouragement. This work was supported by ONR GrantN00014-89-Jll92 to David Van Essen and B.J., NSF Grar.t IBN- 9312224 to J.B. and ChristofKoch, and an AFOSR Grant to C. Koch.
Group:Koch Laboratory (KLAB)
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U.S. Office of Naval ResearchN00014-89-J1192
U.S. Air Force Office of Scientific ResearchUNSPECIFIED
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Record Number:CaltechAUTHORS:20130816-103135736
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:40346
Deposited By: KLAB Import
Deposited On:11 Mar 2010 06:05
Last Modified:09 Nov 2021 23:48

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