Event Abstract Back to Event Neural correlates of bias in decision making Martijn J. Mulder1*, Wouter Boekel1, Eric-Jan Wagenmakers1 and Birte U. Forstmann1 1 University of Amsterdam, Netherlands The speed and accuracy of perceptual decisions are sensitive to expectations about the outcome of a decision. When choosing between two alternatives, one is prone to choose for the alternative that is most profitable (reward amplitude) or most likely (probability). In both scenarios our choice is biased towards the alternative with the most benefit. Little is known about how and where in the brain these bias effects alter choice behavior. In the present study, we used model-based functional MRI to investigate the biasing effects of prior knowledge on simple perceptual decisions. We used two versions of the random-dot motion paradigm in which we manipulated bias by: 1) assigning a larger reward for one of the alternatives (reward amplitude) and 2) manipulating bias by changing the likelihood of one of the alternatives inducing a preference for the more frequent alternative (probability). Subjects performed the task during an fMRI session in a 3T MRI scanner. Additionally, we obtained behavioral data from the same task outside the scanner environment. We used the DMAT toolbox to fit the individual behavioral data to the drift-diffusion model (DDM). Choice bias was measured by calculating differences between DDM-parameters for biased and un-biased conditions. We will include these parameters in future fMRI analyses to identify brain regions that give rise to bias in choice behavior. Preliminary results (n = 18) show more and faster choices towards the alternative that was most probable or had the largest reward amplitude. By fitting the data to the DDM we will be able to measure the effects of bias on the dynamics of the decision process and investigate how the brain gives rise to such adjustments. Funding: Dutch Science Foundation (NWO). Keywords: decision-making, fMRI Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Poster Presentation Topic: Poster Sessions: Decision Making, Reward Processing & Response Selection Citation: Mulder MJ, Boekel W, Wagenmakers E and Forstmann BU (2011). Neural correlates of bias in decision making. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00389 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: 24 Nov 2011; Published Online: 28 Nov 2011. * Correspondence: Dr. Martijn J Mulder, University of Amsterdam, Amsterdam, Netherlands, m.j.mulder@uva.nl 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 Martijn J Mulder Wouter Boekel Eric-Jan Wagenmakers Birte U Forstmann Google Martijn J Mulder Wouter Boekel Eric-Jan Wagenmakers Birte U Forstmann Google Scholar Martijn J Mulder Wouter Boekel Eric-Jan Wagenmakers Birte U Forstmann PubMed Martijn J Mulder Wouter Boekel Eric-Jan Wagenmakers Birte U Forstmann 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.