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Phasic Alertness and Multisensory Integration Contribute to Visual Awareness of Weak Visual Targets in Audio-Visual Stimulation under Continuous Flash Suppression

Cederblad, Anna Matilda Helena and Äijälä, Juho and Andersen, Søren Krogh and MacLeod, Mary Joan and Sahraie, Arash (2022) Phasic Alertness and Multisensory Integration Contribute to Visual Awareness of Weak Visual Targets in Audio-Visual Stimulation under Continuous Flash Suppression. Vision, 6 (2). Art. No. 31. ISSN 2411-5150. PMCID PMC9228768. doi:10.3390/vision6020031.

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Multisensory stimulation is associated with behavioural benefits, including faster processing speed, higher detection accuracy, and increased subjective awareness. These effects are most likely explained by multisensory integration, alertness, or a combination of the two. To examine changes in subjective awareness under multisensory stimulation, we conducted three experiments in which we used Continuous Flash Suppression to mask subthreshold visual targets for healthy observers. Using the Perceptual Awareness Scale, participants reported their level of awareness of the visual target on a trial-by-trial basis. The first experiment had an audio-visual Redundant Signal Effect paradigm, in which we found faster reaction times in the audio-visual condition compared to responses to auditory or visual signals alone. In two following experiments, we separated the auditory and visual signals, first spatially (experiment 2) and then temporally (experiment 3), to test whether the behavioural benefits in our multisensory stimulation paradigm could best be explained by multisensory integration or increased phasic alerting. Based on the findings, we conclude that the largest contributing factor to increased awareness of visual stimuli accompanied by auditory tones is a rise in phasic alertness and a reduction in temporal uncertainty with a small but significant contribution of multisensory integration.

Item Type:Article
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URLURL TypeDescription CentralArticle
Cederblad, Anna Matilda Helena0000-0002-7880-1217
Äijälä, Juho0000-0001-7257-4191
Andersen, Søren Krogh0000-0002-7612-0127
MacLeod, Mary Joan0000-0003-2115-8184
Sahraie, Arash0000-0003-3302-5119
Additional Information:© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( Received: 30 March 2022 / Revised: 12 May 2022 / Accepted: 30 May 2022 / Published: 3 June 2022. Author Contributions. Conceptualization, A.M.H.C., J.Ä. and A.S.; methodology, A.M.H.C., J.Ä. and A.S.; software, A.M.H.C. and J.Ä.; validation, A.M.H.C. and A.S.; formal analysis, A.M.H.C., S.K.A. and A.S.; investigation, A.M.H.C. and A.S.; resources, A.M.H.C. and A.S.; data curation, A.M.H.C. and A.S.; writing—original draft preparation, A.M.H.C. and A.S.; writing—review and editing, A.M.H.C., J.Ä., S.K.A., M.J.M. and A.S.; visualization, A.M.H.C. and A.S.; supervision, S.K.A. and A.S.; project administration, A.M.H.C. and A.S.; funding acquisition, A.M.H.C., S.K.A., M.J.M. and A.S. All authors have read and agreed to the published version of the manuscript. This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/M010996/1]. Institutional Review Board Statement. The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of The University of Aberdeen, UK. Approval code of initial application: PEC/4131/2019/1 [21/01/2019]. Approval codes of updates: PEC/4131/2019/1upd/925 [06/03/2019]; PEC/4131/2019/1upd/981 [16/09/2019]; PEC/4131/2019/1upd/1020 [24/09/2019]; PEC/4131/2019/1 upd/1081 [21/01/2020]. Informed Consent Statement. Informed consent was obtained from all subjects involved in the study. Data Availability Statement. Data available in a publicly accessible repository. The data presented in this study are openly available in Open Science Framework. Access date: 02/06/2022. Doi for the page where the data is stored on the Open Science Framework server: The authors declare no conflict of interest. Furthermore, the funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
Funding AgencyGrant Number
Biotechnology and Biological Sciences Research Council (BBSRC)BB/M010996/1
Subject Keywords:multisensory stimulation; multisensory integrations; alertness; phasic alertness; visual awareness
Issue or Number:2
PubMed Central ID:PMC9228768
Record Number:CaltechAUTHORS:20220608-848989000
Persistent URL:
Official Citation:Cederblad, A.M.H.; Äijälä, J.; Andersen, S.K.; MacLeod, M.J.; Sahraie, A. Phasic Alertness and Multisensory Integration Contribute to Visual Awareness of Weak Visual Targets in Audio-Visual Stimulation under Continuous Flash Suppression. Vision 2022, 6, 31.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115074
Deposited By: George Porter
Deposited On:14 Jun 2022 16:02
Last Modified:28 Jun 2022 21:21

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