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The role of first- and second-order stimulus features for human overt attention

Frey, Hans-Peter and König, Peter and Einhäuser, Wolfgang (2007) The role of first- and second-order stimulus features for human overt attention. Perception and Psychophysics, 69 (2). pp. 153-161. ISSN 0031-5117.

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When processing complex visual input, human observers sequentially allocate their attention to different subsets of the stimulus. What are the mechanisms and strategies that guide this selection process? We investigated the influence of various stimulus features on human overt attention—that is, attention related to shifts of gaze with natural color images and modified versions thereof. Our experimental modifications, systematic changes of hue across the entire image, influenced only the global appearance of the stimuli, leaving the local features under investigation unaffected. We demonstrated that these modifications consistently reduce the subjective interpretation of a stimulus as “natural” across observers. By analyzing fixations, we found that first-order features, such as luminance contrast, saturation, and color contrast along either of the cardinal axes, correlated to overt attention in the modified images. In contrast, no such correlation was found in unmodified outdoor images. Second-order luminance contrast (“texture contrast”) correlated to overt attention in all conditions. However, although none of the second-order color contrasts were correlated to overt attention in unmodified images, one of the second-order color contrasts did exhibit a significant correlation in the modified images. These findings imply, on the one hand, that higher-order bottom-up effects—namely, those of second-order luminance contrast—may partially account for human overt attention. On the other hand, these results also demonstrate that global image properties, which correlate to the subjective impression of a scene being “natural,” affect the guidance of human overt attention

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Additional Information:Copyright 2007 Psychonomic Society, Inc. (Manuscript received April 8, 2005; revision accepted for publication April 11, 2006.) We thank D. C. Kiper for his invaluable support and fruitful discussions. The work was financially supported by Honda RI Europe, EU/BBW (“AMOUSE Project”), and the Swiss National Science Foundation (Grant PBEZ2-107367 to W.E.).
Group:Koch Laboratory (KLAB)
Funding AgencyGrant Number
Swiss National Science FoundationPBEZ2-107367
Subject Keywords:Cognitive Psychology
Issue or Number:2
Record Number:CaltechAUTHORS:20130816-103139545
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:40362
Deposited By: KLAB Import
Deposited On:12 Jan 2008 01:51
Last Modified:03 Oct 2019 05:12

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