An ecological basis for the oblique effect

Abstract

Event Abstract Back to Event An ecological basis for the oblique effect Psychophysical observers are better at a range of discrimination and detection tasks when stimuli are oriented horizontally and vertically rather than at oblique angles. This is known as the Oblique Effect. As there is a higher prevalence of horizontal and vertical energy in natural scenes, it seems natural to ask whether the effect flows from the visual system’s attempt to efficiently represent its input. One approach is to find out if models of vision that efficiently incorporate the statistics in natural images also exhibit the oblique effect. Here I show that the Olshausen and Field model of simple cells, which attempts to extract the sparse, independent, linear components of natural images, produces (1) more units tuned to cardinal than oblique angles, (2) narrower orientation tuning for units tuned to cardinal axes, and (3) greater overall activity in response to cardinal inputs than oblique. The narrower orientation tuning is specifically due to non-linear interactions between competing output units. All of these attributes have either been observed in primate brains or have been postulated as possible causes for the psychophysically observed oblique effect. In the first two cases listed above, the oblique versus cardinal differences for the model are greater (in the range of 20% to 60%) than those observed in neural studies. When images of a modern, carpentered environment are used in place of natural images, the differences become larger still. In other words, efficient representation of naturally encountered images under the Olshausen framework predicts an exaggerated oblique effect. This indicates that efficiency is likely to be an important contributor to the oblique effect but that other factors also play a role, effectively moderating the exaggerated effect produced by efficient coding considerations on their own. Conference: Computational and systems neuroscience 2009, Salt Lake City, UT, United States, 26 Feb - 3 Mar, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: (2009). An ecological basis for the oblique effect. Front. Syst. Neurosci. Conference Abstract: Computational and systems neuroscience 2009. doi: 10.3389/conf.neuro.06.2009.03.066 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: 30 Jan 2009; Published Online: 30 Jan 2009. 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 Google Google Scholar PubMed 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.