Event Abstract Back to Event Model of visual target detection applied to rat behavior Philip Meier1* and Pamela Reinagel1 1 University of California at San Diego, United States The perception of visual features is influenced by the nearby spatial context of an image. Such contextual processing may be useful for natural vision, and can be experimentally revealed. In previous work, we have shown that rat’s behavioral performance on a visual task is influenced by the relationship of features: specifically, collinear flankers make it more difficult to detect the presence of an oriented target. It is known that the contrast of the center target and surround flankers influence human and monkey behavior as well as cat and monkey neurophysiology. Here we present new rat behavioral data on the influence the contrast of collinear flankers at multiple target contrasts. Our main finding is that increasing flanker contrast impoverishes target detection and biases rats to report the presence of the target. Interestingly, surround contrast does not mask target detection which would bias the rat to report the absence of a target more often. This runs counter to predictions made by a divisive normalization model. Additionally, the presence of flankers decreases performance. This opposes the hypothesis that the primary influence of flankers is to reduce the uncertainty of the target location. Contextual effects in visual tasks could have multiple causes including normal perceptual processing, the task-specific allocation of attention, optical blurring, neural integration over visual space, and cognitive confusion. Perceptual processing is likely to be responsible for effects of the flankers that are sensitive to the precise geometric configuration, but here we address the influence of contrast within a single configuration by using an uncertainty model with a max decision rule (Pelli, 1985) to account for rats’ behavior. Our model includes an attention term for the suppression of the task irrelevant distracters, and a spatial integration term that represents feature pooling. With a small number of parameters (attention spatial focus, feature pooling magnitude, channel noise, number of channels, contrast sensitivity function) the model qualitatively captures the trends of the flanker’s influence on bias and performance. If a fixed decision threshold is used, the model predicts that subjects would have a variable hit rate and a constant false alarm rate for a given flanker contrast. However, rats display a false alarm rates that increase with flanker contrast. Rats probably change their decision criteria for different stimulus conditions because conditions are blocked into 150 trials with the same stimulus parameters. A model with an adaptive decision criterion is proposed to better fit the hit rates and false alarms. We note that the model only contains knowledge of contrast, and does not attempt to explain results that depend on interactions of orientations or stimulus configuration. Which stage of the rat’s visual system is responsible for the influence of the flankers? To narrow down the cause of lateral interaction, we have begun to present collinear stimuli of varying contrasts while recording extra-cellular spikes from the lateral geniculate nucleus of the rat. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session III Citation: Meier P and Reinagel P (2010). Model of visual target detection applied to rat behavior. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00284 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: 05 Mar 2010; Published Online: 05 Mar 2010. * Correspondence: Philip Meier, University of California at San Diego, San Diego, United States, pmeier@ucsd.edu 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 Philip Meier Pamela Reinagel Google Philip Meier Pamela Reinagel Google Scholar Philip Meier Pamela Reinagel PubMed Philip Meier Pamela Reinagel 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.