Binding colour to object surfaces in the human visual cortex.

Abstract

Event Abstract Back to Event Binding colour to object surfaces in the human visual cortex. Kiley J. Seymour1*, Mark A. Williams1, 2 and Anina N. Rich1, 2 1 Macquarie University, Cognitive Science, Australia 2 ARC Centre of Excellence in Cognition & its Disorders, Australia Background: Many theories of visual object perception assume that the visual system initially extracts borders between the object and its background through figure-ground segmentation and later binds colour to the resulting object surfaces. However the neural representation of surface colour in human visual cortex is largely unknown. Here, we tested which levels of the visual system contain specific information about the surface colour of objects. Methods: We used a 3T MRI scanner to collect fMRI data while participants viewed isoluminant red/green square-wave radial gratings. The two sets of stimuli varied only in whether the red or green part of the grating fell at a particular retinal location (e.g., 12 o’clock position) and whether it appeared as a red fan on a green background or a green fan on a red background due to a slight change of contextual information. We used multivariate pattern analysis (MVPA) to investigate in which visual brain areas a classifier could distinguish the colour (red vs. green) at a set location versus the object (red vs. green) independent of its position on the retina. We also determined whether brain signals in these areas were dominated by object position or surface colour information. Results: Our preliminary results show that classifiers are able to decode information about which colour was presented at a particular retinal location from early visual areas. Further classifier analysis also revealed that these areas contain strong colour-invariant information about object position to support the early extraction of object borders within a visual scene. Areas further along the ventral stream, in contrast, represent object surface colour, which is position-invariant. Discussion: These findings are consistent with theories of feature binding that suggest colour is bound to object surfaces after figure-ground segmentation. Acknowledgements This work was supported under the Australian Research Council (ARC)’s Discovery Projects funding scheme (ANR: DP0984494) and Macquarie University internal grant schemes. MAW and ANR are recipients of ARC Fellowships (Queen Elizabeth II Research Fellowship DP0984919, and Australian Postdoctoral Fellowship DP0984494, respectively). Keywords: visual feature binding, object perception, fMRI methods, Visual Cortex, Figure-ground Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Oral Topic: Sensation and Perception Citation: Seymour KJ, Williams MA and Rich AN (2013). Binding colour to object surfaces in the human visual cortex.. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00028 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: 23 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Dr. Kiley J Seymour, Macquarie University, Cognitive Science, Sydney, Australia, kileys@psych.usyd.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 Kiley J Seymour Mark A Williams Anina N Rich Google Kiley J Seymour Mark A Williams Anina N Rich Google Scholar Kiley J Seymour Mark A Williams Anina N Rich PubMed Kiley J Seymour Mark A Williams Anina N Rich 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.