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Attentional effects on contrast detection in the presence of surround masks

Zenger, Barbara and Braun, Jochen and Koch, Christof (2000) Attentional effects on contrast detection in the presence of surround masks. Vision Research, 40 (27). pp. 3717-3724. ISSN 0042-6989. doi:10.1016/S0042-6989(00)00218-2.

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We studied how attention affects contrast detection performance when the target is surrounded by mask elements. In each display quadrant we presented a hexagon of six vertical Gabor patches (the ‘surround’). Only one of the hexagons contained a central Gabor patch (the ‘target’) and the task was to report that quadrant (spatial four-alternative-forced choice). Attention was manipulated by means of a double-task paradigm: in one condition observers had to perform concurrently a central letter-discrimination task, and the contrast-detection task was then only poorly attended, while attention was fully available in the other condition. We find that under poorly attended conditions targets can be detected only when the target contrast exceeds the surround contrast (contrast popout) or when the target orientation differs from the surround orientation by more than 10–15° (orientation popout). When the target orientation is similar to the surround orientation, attention can reduce the contrast detection thresholds in some cases more than four-fold, demonstrating a very strong attentional effect.

Item Type:Article
Related URLs:
URLURL TypeDescription
Koch, Christof0000-0001-6482-8067
Additional Information:© 2000 Elsevier Science Ltd. Received 9 March 2000; received in revised form 26 July 2000. We would like to thank Geraint Rees for helpful discussions. This research was supported by NSF, the NAF-sponsored Neuromorphic Engineering Center, and NIMH. BZ acknowledges a fellowship from Caltech's Division of Biology.
Group:Koch Laboratory (KLAB)
Funding AgencyGrant Number
NAF-sponsored Neuromorphic Engineering CenterUNSPECIFIED
Subject Keywords:Attention; Contrast; Detection; Surround interactions; Segmentation
Issue or Number:27
Record Number:CaltechAUTHORS:20130816-103239950
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:40551
Deposited By: KLAB Import
Deposited On:11 Jan 2008 20:12
Last Modified:09 Nov 2021 23:49

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