Luminance and Colour Flicker Fusion in High and Low Autistic Traits

Abstract

Event Abstract Back to Event Luminance and Colour Flicker Fusion in High and Low Autistic Traits Alyse Brown1*, David P. Crewther1, Julia Thompson1, Georgette Karvelas1, Catherine Guarnaccia1, Charlotte Hartwell1 and Claire Peck1 1 Swinburne University, Australia Background Neurophysiological mechanisms underlying altered visual perception in autistic tendencies are currently poorly defined. Differences in magnocellular processing have been implicated in the impaired motion sensitivity and different global/local integration style associated with autistic tendency. Method Flicker fusion tasks were utilised to examine temporal processing differences in a non-clinical population displaying high and low autistic tendencies as measured by Baron-Cohen’s Autism spectrum Quotient (AQ). Isoluminant red/green flicker was used to measure temporal processing capacity of the parvocellular system (2AFC) and similarly, isoluminant blue/yellow flicker used to measure koniocellular pathway function (2AFC). The temporal processing capacity of the magnocellular system was measured as a function of contrast with critical luminance flicker thresholds measured at 5 different temporal contrast levels (5%, 25%, 50%, 75%, 100%) using a 4AFC method. Calibrated LEDs were viewed through 5mm diameter optic fibers, amplitude, DC level and frequencies were modulated using VPixx software via a DataPIXX interface system. Results Data obtained supports previous findings showing critical flicker thresholds improve with increasing contrast levels, from 32Hz at 5% contrast to 47Hz at 100% temporal contrast (correlation R2 =.47, significant to .001). Blue/yellow flicker had a marginally higher mean colour fusion rate (18.3Hz) than the red/green fusion task (16.8 Hz). Between groups analysis shows for all flicker tasks that individuals with high AQ have lower luminance flicker fusion rates then those with low AQ. Discussion The finding that those with higher AQ scores are less able to perceive flicker – especially for luminance modulation at the limits of high frequency, is suggestive of impaired magnocellular function, despite previous reports of insignificant differences in flicker contrast sensitivity. Keywords: temporal processing, autistic traits, Flicker Fusion, Magnocellular, Parvocellular Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Sensation and Perception Citation: Brown A, Crewther DP, Thompson J, Karvelas G, Guarnaccia C, Hartwell C and Peck C (2013). Luminance and Colour Flicker Fusion in High and Low Autistic Traits. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00091 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: 25 Sep 2013; Published Online: 25 Nov 2013. * Correspondence: Ms. Alyse Brown, Swinburne University, Melbourne, Australia, amailboxx@hotmail.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 Alyse Brown David P Crewther Julia Thompson Georgette Karvelas Catherine Guarnaccia Charlotte Hartwell Claire Peck Google Alyse Brown David P Crewther Julia Thompson Georgette Karvelas Catherine Guarnaccia Charlotte Hartwell Claire Peck Google Scholar Alyse Brown David P Crewther Julia Thompson Georgette Karvelas Catherine Guarnaccia Charlotte Hartwell Claire Peck PubMed Alyse Brown David P Crewther Julia Thompson Georgette Karvelas Catherine Guarnaccia Charlotte Hartwell Claire Peck 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.