Changes in functional connectivity support changes in visibility

Abstract

Event Abstract Back to Event Changes in functional connectivity support changes in visibility Fatma Imamoglu1, 2*, Jakob Heinzle1, 2, 3, Adrian Imfeld1 and John-Dylan Haynes1, 2, 4 1 Bernstein Center for Computational Neuroscience, Charite Universitätsmedizin, Germany 2 Berlin Center for Advanced Neuroimaging, Charite Universitätsmedizin, Germany 3 Translational Neuromodeling Unit (TNU) Institute for Biomedical Engineering University of Zurich & ETH Zurich,, Switzerland 4 Humboldt-Universität zu Berlin, Germany The neural basis of stimulus visibility is tightly linked to the quest for the neural correlates of conscious perception. Experimentally, stimulus visibility can be altered using stimulus manipulation techniques such as visual masking. In visual masking a target stimulus is rendered invisible by varying the timing of a mask that is followed by the target stimulus. Importantly, the physical appearance of the target stimulus is not changed during stimulus presentation. Here, we used functional magnetic resonance imaging (fMRI) to investigate to what extent the visibility of the target stimulus is reflected by functional connectivity changes in the human brain. Oriented grating stimuli were presented under varying visibility conditions created by backward masking. Visibility was manipulated by using four different stimulus onset asynchronies (SOA), which created a continuum from invisible to highly visible target stimuli. Masking performance was tested in a separate behavioral experiment prior to the fMRI experiment. In addition, subjects were asked to report the orientation of the grating with a button press during the fMRI scan. Subjects who responded correctly to the highest visibility condition and were at chance level to the lowest visibility condition were selected for the fMRI analysis. First, we selected regions of interests from brain activations that were activated independent of different visibility conditions. This revealed intraparietal sulcus, dorsolateral prefrontal cortex, inferior frontal gyrus, early visual, and higher visual areas. We computed a parametric functional connectivity analysis using these regions of interests and showed that increased stimulus visibility is reflected in the coupling between early and higher visual areas. Specifically, higher visual areas are significantly more correlated with early visual areas when the visual stimulus presented is visible to the subject than when it is invisible. This provides evidence that dynamic changes in functional connectivity reflect conscious perception. Keywords: functional connectivity, functional magnetic resonance imaging (fMRI), Visual awareness Conference: Bernstein Conference 2012, Munich, Germany, 12 Sep - 14 Sep, 2012. Presentation Type: Poster Topic: Sensory processing and perception Citation: Imamoglu F, Heinzle J, Imfeld A and Haynes J (2012). Changes in functional connectivity support changes in visibility. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference 2012. doi: 10.3389/conf.fncom.2012.55.00003 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 07 May 2012; Published Online: 12 Sep 2012. * Correspondence: Miss. Fatma Imamoglu, Bernstein Center for Computational Neuroscience, Charite Universitätsmedizin, Berlin, Germany, fatmaimamoglu@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Fatma Imamoglu Jakob Heinzle Adrian Imfeld John-Dylan Haynes Google Fatma Imamoglu Jakob Heinzle Adrian Imfeld John-Dylan Haynes Google Scholar Fatma Imamoglu Jakob Heinzle Adrian Imfeld John-Dylan Haynes PubMed Fatma Imamoglu Jakob Heinzle Adrian Imfeld John-Dylan Haynes Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.