title: Characterization and compensation of network-level anomalies in mixed-signal neuromorphic modeling platforms.
abstract: Advancing the size and complexity of neural network models leads to an ever increasing demand for computational resources for their simulation. Neuromorphic devices offer a number of advantages over conventional computing architectures, such as high emulation speed or low power consumption, but this usually comes at the price of reduced configurability and precision. In this article, we investigate the consequences of several such factors that are common to neuromorphic devices, more specifically limited hardware resources, limited parameter configurability and parameter variations due to fixed-pattern noise and trial-to-trial variability. Our final aim is to provide an array of methods for coping with such inevitable distortion mechanisms. As a platform for testing our proposed strategies, we use an executable system specification (ESS) of the BrainScaleS neuromorphic system, which has been designed as a universal emulation back-end for neuroscientific modeling. We address the most essential limitations of this device in detail and study their effects on three prototypical benchmark network models within a well-defined, systematic workflow. For each network model, we start by defining quantifiable functionality measures by which we then assess the effects of typical hardware-specific distortion mechanisms, both in idealized software simulations and on the ESS. For those effects that cause unacceptable deviations from the original network dynamics, we suggest generic compensation mechanisms and demonstrate their effectiveness. Both the suggested workflow and the investigated compensation mechanisms are largely back-end independent and do not require additional hardware configurability beyond the one required to emulate the benchmark networks in the first place. We hereby provide a generic methodological environment for configurable neuromorphic devices that are targeted at emulating large-scale, functional neural networks.
authors.affiliation: Ruprecht-Karls-Universität Heidelberg, Kirchhoff Institute for Physics, Heidelberg, Germany.
authors.forename: Mihai A
authors.initials: MA
authors.lastname: Petrovici
authors.affiliation: Technische Universität Dresden, Institute of Circuits and Systems, Dresden, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Vogginger
authors.affiliation: Ruprecht-Karls-Universität Heidelberg, Kirchhoff Institute for Physics, Heidelberg, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Müller
authors.affiliation: Ruprecht-Karls-Universität Heidelberg, Kirchhoff Institute for Physics, Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Breitwieser
authors.affiliation: Department of Computational Biology, School of Computer Science and Communication, Stockholm University and Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Lundqvist
authors.affiliation: CNRS, Unité de Neuroscience, Information et Complexité, Gif sur Yvette, France.
authors.forename: Lyle
authors.initials: L
authors.lastname: Muller
authors.affiliation: Technische Universität Dresden, Institute of Circuits and Systems, Dresden, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ehrlich
authors.affiliation: CNRS, Unité de Neuroscience, Information et Complexité, Gif sur Yvette, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Destexhe
authors.affiliation: Department of Computational Biology, School of Computer Science and Communication, Stockholm University and Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Lansner
authors.affiliation: Technische Universität Dresden, Institute of Circuits and Systems, Dresden, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Schüffny
authors.affiliation: Ruprecht-Karls-Universität Heidelberg, Kirchhoff Institute for Physics, Heidelberg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Schemmel
authors.affiliation: Ruprecht-Karls-Universität Heidelberg, Kirchhoff Institute for Physics, Heidelberg, Germany.
authors.forename: Karlheinz
authors.initials: K
authors.lastname: Meier
mesh_terms: D003198:Computer Simulation; D003199:Computer Systems; D003201:Computers; D004867:Equipment Design; D008959:Models, Neurological; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology; D012984:Software