A1 Refereed original research article in a scientific journal
Top-down preparation modulates visual categorization but not subjective awareness of objects presented in natural backgrounds
Authors: Koivisto M, Kahila E
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Publication year: 2017
Journal: Vision Research
Journal name in source: VISION RESEARCH
Journal acronym: VISION RES
Volume: 133
First page : 73
Last page: 80
Number of pages: 8
ISSN: 0042-6989
DOI: https://doi.org/10.1016/j.visres.2017.01.005
Self-archived copy’s web address: https://research.utu.fi/converis/portal/Publication/25154932?auxfun=〈=fi_FI
Abstract
Top-down processes are widely assumed to be essential in visual awareness, subjective experience of seeing. However, previous studies have not tried to separate directly the roles of different types of top-down influences in visual awareness. We studied the effects of top-down preparation and object substitution masking (OSM) on visual awareness during categorization of objects presented in natural scene backgrounds. The results showed that preparation facilitated categorization but did not influence visual awareness. OSM reduced visual awareness and impaired categorization. The dissociations between the effects of preparation and OSM on visual awareness and on categorization imply that they influence at different stages of cognitive processing. We propose that preparation influences at the top of the visual hierarchy, whereas OSM interferes with processes occurring at lower levels of the hierarchy. These lower level processes play an essential role in visual awareness. (C) 2017 Elsevier Ltd. All rights reserved.
Top-down processes are widely assumed to be essential in visual awareness, subjective experience of seeing. However, previous studies have not tried to separate directly the roles of different types of top-down influences in visual awareness. We studied the effects of top-down preparation and object substitution masking (OSM) on visual awareness during categorization of objects presented in natural scene backgrounds. The results showed that preparation facilitated categorization but did not influence visual awareness. OSM reduced visual awareness and impaired categorization. The dissociations between the effects of preparation and OSM on visual awareness and on categorization imply that they influence at different stages of cognitive processing. We propose that preparation influences at the top of the visual hierarchy, whereas OSM interferes with processes occurring at lower levels of the hierarchy. These lower level processes play an essential role in visual awareness. (C) 2017 Elsevier Ltd. All rights reserved.
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