Behaviourally relevant temporal dynamics of local statistics in natural images

Abstract

Event Abstract Back to Event Behaviourally relevant temporal dynamics of local statistics in natural images Alexander Schwegmann1*, Jens P. Lindemann1 and Martin Egelhaaf1 1 Bielefeld University, Biology, Germany Evolution is assumed to have shaped the sensory systems of animals to process their typical input at the best according to a given computational task. Parallel to evolving optimized sensory systems animals acquired behavioural strategies that actively shape the input in order to facilitate extraction of the relevant information. For example, the saccadic flight in blowflies is assumed to separate translational and rotational components of retinal image movements already at the behavioural level. To understand the functioning of a visual system, it is important to analyse the temporal changes in statistical properties of the natural visual input of behaving animals. So far research has either focused on the global statistics of static natural scenes or analysed the time course of the input of single photo receptors. To assess to what extent the visual system has to deal with variations in local image statistics we recorded image sequences in a large variety of cluttered natural environments using a green-sensitive high dynamic range panorama camera. The camera was linearly displaced along 1 m to approximate the translatory motion during the intersaccadic intervals of freely flying flies. Saccadic rotations were approximated by image rotation of the panoramic images at the beginning and end of the movement trajectory. The distortions added by the panoramic mirror were computationally removed and the intensity remapped to represent the true intensity values linearly. The analysis was performed on differently sized image patches at different viewing directions and across different scenes taken at places with differing spatial layout. We analysed first order statistics like the time course of local luminance, the contrast, and second order statistics like the overall spatial power spectra and the spatial power along different directions. The distributions of the statistical parameters depend strongly on the scene type. Temporal changes during translational movements are much smaller than those observed during rotations (up to a factor of 20). Distinct changes during translations are only elicited by nearby objects. Fluctuations in the analysed statistical parameters are stronger within small image patches than in large ones. Furthermore the patch size in the tested range has no distinct influence on the mean luminance and spatial frequency spectrum, but on the r.m.s. contrast. Keywords: adaptation, motion vision, natural image statistics, temporal statistics Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for student poster award) Topic: Sensory: Vision Citation: Schwegmann A, Lindemann JP and Egelhaaf M (2012). Behaviourally relevant temporal dynamics of local statistics in natural images. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00091 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: 19 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Mr. Alexander Schwegmann, Bielefeld University, Biology, Bielefeld, D-33501, Germany, alexander.schwegmann@uni-bielefeld.de 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 Alexander Schwegmann Jens P Lindemann Martin Egelhaaf Google Alexander Schwegmann Jens P Lindemann Martin Egelhaaf Google Scholar Alexander Schwegmann Jens P Lindemann Martin Egelhaaf PubMed Alexander Schwegmann Jens P Lindemann Martin Egelhaaf 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.