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A direct comparison of unconscious face processing under masking and interocular suppression

Izatt, Gregory and Dubois, Julien and Faivre, Nathan and Koch, Christof (2014) A direct comparison of unconscious face processing under masking and interocular suppression. Frontiers in Psychology, 5 . Art. No. 659. ISSN 1664-1078. PMCID PMC4083827.

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Different combinations of forward and backward masking as well as interocular suppression have been used extensively to render stimuli invisible and to study those aspects of visual stimuli that are processed in the absence of conscious experience. Although the two techniques—masking vs. interocular suppression—obviously differ both in their applications and mechanisms, only little effort has been made to compare them systematically. Yet, such a comparison is crucial: existing discrepancies in the extent of unconscious processing inferred from these two techniques must be reconciled, as our understanding of unconscious vision should be independent of the technique used to prevent visibility. Here, we studied similarities and differences between faces rendered invisible by masking vs. interocular suppression using a priming paradigm. By carefully equating stimulus strength across the two techniques, we analyzed the effects of face primes with the same viewpoint (repetition priming, Experiment 1) and of face primes with a different viewpoint (identity priming, Experiment 2) on the reaction times for a fame categorization task. Overall, we found that the magnitude of both repetition and identity priming largely depended on stimulus visibility. Moreover, when the primes were subjectively invisible, both repetition and identity priming were found to be qualitatively stronger under masking than under interocular suppression. Taken together, these results help refine our understanding of which level of visual processing each technique disrupts, and illustrate the importance of systematic methodological comparisons in the field of unconscious vision.

Item Type:Article
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URLURL TypeDescription DOIArticle Material CentralArticle
Dubois, Julien0000-0002-3029-173X
Faivre, Nathan0000-0001-6011-4921
Koch, Christof0000-0001-6482-8067
Additional Information:© 2014 Izatt, Dubois, Faivre and Koch. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Received: 09 April 2014; Accepted: 09 June 2014; Published online: 07 July 2014. This research, and Julien Dubois, were supported by the G. Harold and Leila Y. Mathers Charitable Foundation, Nathan Faivre by the Fyssen Foundation, Gregory Izatt by a Summer Undergraduate Research Fellowship from the California Institute of Technology. The authors are very grateful to Hagar Gelbard-Sagiv for providing some of the face images used in our experiments.
Group:Koch Laboratory (KLAB)
Funding AgencyGrant Number
G. Harold and Leila Y. Mathers Charitable FoundationUNSPECIFIED
Fyssen FoundationUNSPECIFIED
Caltech Summer Undergraduate Research Fellowship (SURF)UNSPECIFIED
Subject Keywords:masking; backward masking; interocular suppression; continuous flash suppression; face processing; priming; awareness; consciousness
PubMed Central ID:PMC4083827
Record Number:CaltechAUTHORS:20140807-084752292
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Official Citation:Izatt G, Dubois J, Faivre N and Koch C (2014) A direct comparison of unconscious face processing under masking and interocular suppression. Front. Psychol. 5:659. doi: 10.3389/fpsyg.2014.00659
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:48163
Deposited By: Jason Perez
Deposited On:08 Aug 2014 21:57
Last Modified:09 Mar 2020 13:18

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