Cortical excitability modulates the sensory strength of visual mental imagery

Abstract

Event Abstract Back to Event Cortical excitability modulates the sensory strength of visual mental imagery Rebecca Keogh1* and Joel Pearson1* 1 University of New South Wales, Australia Visual mental imagery occurs when people generate a mental representation of an image that is not physically present. One of the hallmarks of mental imagery is the large variance in reported vividness and strength of imagery between individuals. Numerous studies to date using neuroimaging and behavioural techniques have suggested that the early visual areas play an important role in imagery generation, however the exact cause of individual variance in mental imagery strength remains unknown. Here we used transcranial magnetic stimulation (TMS) to measure the cortical excitability of the visual cortex (using an automated phosphene threshold procedure). To measure imagery strength participants imagined one of two patterns followed by the presentation of a brief binocular rivalry display. Imagery strength was measured as the percent imagery primed rivalry. We found a negative correlation between cortical excitability and imagery strength. We then investigated whether we could manipulate imagery strength through increasing or decreasing cortical excitability of the early visual areas by using transcranial direct current stimulation (tDCS). tDCS uses a weak electrical current to increase (anodal) or decrease (cathodal) cortical excitability in the area under the active electrode. All participants completed both the cathodal and anodal conditions of this study on two separate days. tDCS was applied during the imagery task and performance was measured before, during and immediately after (post) tDCS. Cathodal stimulation increased imagery strength during stimulation, however no increases were found post-stimulation. Anodal stimulation had no effect on imagery strength during or after stimulation. Taken together these results suggest that visual cortex excitability plays a key role in governing the strength of mental imagery. Keywords: imagery, tDCS, Binocular Rivalry, TMS, cortical excitability Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Cognition and Executive Processes Citation: Keogh R and Pearson J (2015). Cortical excitability modulates the sensory strength of visual mental imagery. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00301 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: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Miss. Rebecca Keogh, University of New South Wales, Sydney, Australia, r.keogh@unsw.edu.au Dr. Joel Pearson, University of New South Wales, Sydney, Australia, jpearson@unsw.edu.au 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 Rebecca Keogh Joel Pearson Google Rebecca Keogh Joel Pearson Google Scholar Rebecca Keogh Joel Pearson PubMed Rebecca Keogh Joel Pearson 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.