Friday 7th Feb 2013 – Dr James A. Bednar

Dr James A. Bednar – University of Edinburgh

A Mechanistic Model of the Development and Function of the Primary Visual Cortex

Abstract
Previous computational models of adult primary visual cortex (V1) have been able to account for many of the measured properties of V1 neurons, but not how or why these particular properties arise. Conversely, previous models of how V1 originally develops have been able to reproduce the overall organization of specific feature maps in V1, such as orientation maps, but the neurons in the simulated maps are typically too abstract even to be testable with visual stimuli. I believe that the complex adult circuitry can be understood much better by considering the developmental process that created it, and conversely, that an explanation of the developmental process is only meaningful if it is leading to a system that can perform behaviourally relevant visual tasks.

Accordingly, in this talk I outline a long-term project to build the first model to explain both the development and the function of V1. To do this, researchers in my group are building the first developmental models with wiring consistent with V1, the first to have realistic behavior with respect to visual contrast, the first to include all of the various visual feature dimensions, and the first to include all of the major sources of connectivity that modulate V1 neuron responses. The goal is to have a comprehensive explanation for why V1 is wired as it is in the adult, and how that circuitry leads to the observed behavior of the neurons during visual tasks. This approach leads to experimentally testable predictions at each stage, and can also be applied to understanding other sensory cortices, such as somatosensory and auditory cortex.

Reviews work from:

Stevens et al. (2013), J. Neuroscience, 33:15747-15766.
http://dx.doi.org/10.1523/JNEUROSCI.1037-13.2013

Bednar (2012), J. Physiology-Paris, 106:194-211.
http://dx.doi.org/10.1016/j.jphysparis.2011.12.001

Bio
Dr James A. Bednar leads the Computational Systems Neuroscience Group at the University of Edinburgh, and is the Director of the Edinburgh Doctoral Training Centre in Neuroinformatics and Computational Neuroscience, which has 60 current PhD students. His Ph.D. in Computer Science is from the University of Texas at Austin, and he also has degrees in Philosophy and Electrical Engineering. His research focuses on computational modeling of the development and function of mammalian visual systems. He is a co-author of the monograph “Computational Maps in the Visual Cortex” (Springer, 2005), and is the lead author of the Topographica cortical modeling software package. He has been on the Board of Directors for the annual international Computational Neuroscience Meeting, and is a Member of the Review Editorial Board for the journals Frontiers in Neuroinformatics and Frontiers in Computational Neuroscience.

http://homepages.inf.ed.ac.uk/jbednar/
http://topographica.org

School of Computing Science & Digital Media, Robert Gordon University, Riverside East, Garthdee, Aberdeen, Conference Room N204, 14:10 – 15:10.

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School of Computing Science and Digital Media, Robert Gordon University, Aberdeen, Scotland
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