Event Abstract Back to Event Distinct computations at perceptual, central and motor stages during perceptual choice Christopher Summerfield1*, Valentin Wyart1, Vincent De Gardelle2 and Nicholas Myers1 1 University of Oxford, Department of Experimental Psychology, United Kingdom 2 Laboratoire Psychologie de la Perception (CNRS UMR 8158) Université Paris Descartes, France Computational accounts of perceptual choice, such as the drift-diffusion model, propose that beliefs about the perceptual world are embodied in the preparatory signals that precede decision-appropriate motor responses. By contrast, cognitive scientists argue that decision-relevant evidence is encoded and weighted at a capacity-limited central stage, preceding response preparation. Here, we describe combined computational modelling and neuroimaging evidence supporting the latter view. Human observers judged whether a rapid stream of eight visual gratings was, on average, tilted closer to the cardinal or diagonal axes, during fMR imaging. We simulated task performance with a feedforward connectionist network in which information in distributed population codes flowed between perceptual, central and motor stages. Across samples (gratings), activity of central units mimicked that of neurons in the parietal cortex during evidence integration. However, aggregate changes in population activity occurring after each new sample of evidence allowed us to make predictions about BOLD activity at perceptual, central and motor stages. As expected, gross changes in simulated activity at perceptual and motor stages were associated with BOLD signals in the visual and motor cortices. However, updates to central activity (which also scaled with sample-by-sample changes to the posterior distribution estimated by a Bayesian learner performing the task) correlated with BOLD signals in the parietal, cingulate and insular cortices. This activity is not predicted by a diffusion process in which relative evidence in favour of two motor acts is accumulated. These data suggest that perceptual choices depend on distributed neural codes at distinct perceptual, central and motor stages. Keywords: Bayesian learning, Decision Theory, human fMRI Conference: Neural Coding, Decision-Making & Integration in Time, Rauischholzhausen, Germany, 26 Apr - 29 Apr, 2012. Presentation Type: Poster Presentation Topic: Neural Coding, Decision-Making & Integration in Time Citation: Summerfield C, Wyart V, De Gardelle V and Myers N (2012). Distinct computations at perceptual, central and motor stages during perceptual choice. Front. Neurosci. Conference Abstract: Neural Coding, Decision-Making & Integration in Time. doi: 10.3389/conf.fnins.2012.86.00018 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: 12 Jan 2012; Published Online: 16 Jan 2012. * Correspondence: Dr. Christopher Summerfield, University of Oxford, Department of Experimental Psychology, Oxford, United Kingdom, christopher.summerfield@psy.ox.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract Supplemental Data The Authors in Frontiers Christopher Summerfield Valentin Wyart Vincent De Gardelle Nicholas Myers Google Christopher Summerfield Valentin Wyart Vincent De Gardelle Nicholas Myers Google Scholar Christopher Summerfield Valentin Wyart Vincent De Gardelle Nicholas Myers PubMed Christopher Summerfield Valentin Wyart Vincent De Gardelle Nicholas Myers 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.