Buckley, C., Bullock, S. and Cohen, N. (2004) Toward a dynamical systems analysis of neuromodulation. In: Schaal, S., Ijspeert, A.J., Billard, A., Vijayakumar, S., Hallam, J. and Meyer, J-A., (eds.) From Animals to Animats 8: Proceedings of the Eighth International Conference on the Simulation of Adaptive Behavior. SAB'04, 13 - 17 July 2004, Los Angeles, CA, USA. MIT Press , Cambridge, Mass. , pp. 334-343. ISBN 978-0-262-69341-7
This work presents some first steps toward a more thorough understanding of the control systems employed in evolutionary robotics. In order to choose an appropriate architecture or to construct an effective novel control system we need insights into what makes control systems successful, robust, evolvable, etc. Here we present analysis intended to shed light on this type of question as it applies to a novel class of artificial neural networks that include a neuromodulatory mechanism: GasNets. We begin by instantiating a particular GasNet subcircuit responsible for tuneable pattern generation and thought to underpin the attractive property of “temporal adaptivity”. Rather than work within the GasNet formalism, we develop an extension of the well-known FitzHugh-Nagumo equations. The continuous nature of our model allows us to conduct a thorough dynamical systems analysis and to draw parallels between this subcircuit and beating/bursting phenomena reported in the neuroscience literature. We then proceed to explore the effects of different types of parameter modulation on the system dynamics. We conclude that while there are key differences between the gain modulation used in the GasNet and alternative schemes (including threshold modulation of more traditional synaptic input), both approaches are able to produce tuneable pattern generation. While it appears, at least in this study, that the GasNet’s gain modulation may not be crucial to pattern generation , we go on to suggest some possible advantages it could confer.
|Copyright, Publisher and Additional Information:||This is an author produced version of a paper published in 'From Animals to Animats 8: Proceedings of the Eighth International Conference on the Simulation of Adaptive Behavior'. Uploaded in accordance with the publisher's self-archiving policy.|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Engineering (Leeds) > School of Computing (Leeds)|
|Depositing User:||Miss Jamie Grant|
|Date Deposited:||12 Mar 2009 18:04|
|Last Modified:||16 Sep 2016 13:45|