Computation in Dynamically Bounded Asymmetric Systems

Previous explanations of computations performed by recurrent networks have focused on symmetrically connected saturating neurons and their convergence toward attractors. Here we analyze the behavior of asymmetrical connected networks of linear threshold neurons, whose positive response is unbounded....

Full description

Bibliographic Details
Main Authors: Rutishauser, Ueli, Douglas, Rodney J., Slotine, Jean-Jacques E.
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Language:en_US
Published: Public Library of Science 2015
Online Access:http://hdl.handle.net/1721.1/94559
https://orcid.org/0000-0002-7161-7812
_version_ 1826192911312617472
author Rutishauser, Ueli
Douglas, Rodney J.
Slotine, Jean-Jacques E.
author2 Massachusetts Institute of Technology. Department of Mechanical Engineering
author_facet Massachusetts Institute of Technology. Department of Mechanical Engineering
Rutishauser, Ueli
Douglas, Rodney J.
Slotine, Jean-Jacques E.
author_sort Rutishauser, Ueli
collection MIT
description Previous explanations of computations performed by recurrent networks have focused on symmetrically connected saturating neurons and their convergence toward attractors. Here we analyze the behavior of asymmetrical connected networks of linear threshold neurons, whose positive response is unbounded. We show that, for a wide range of parameters, this asymmetry brings interesting and computationally useful dynamical properties. When driven by input, the network explores potential solutions through highly unstable ‘expansion’ dynamics. This expansion is steered and constrained by negative divergence of the dynamics, which ensures that the dimensionality of the solution space continues to reduce until an acceptable solution manifold is reached. Then the system contracts stably on this manifold towards its final solution trajectory. The unstable positive feedback and cross inhibition that underlie expansion and divergence are common motifs in molecular and neuronal networks. Therefore we propose that very simple organizational constraints that combine these motifs can lead to spontaneous computation and so to the spontaneous modification of entropy that is characteristic of living systems.
first_indexed 2024-09-23T09:31:03Z
format Article
id mit-1721.1/94559
institution Massachusetts Institute of Technology
language en_US
last_indexed 2024-09-23T09:31:03Z
publishDate 2015
publisher Public Library of Science
record_format dspace
spelling mit-1721.1/945592022-09-30T14:57:06Z Computation in Dynamically Bounded Asymmetric Systems Rutishauser, Ueli Douglas, Rodney J. Slotine, Jean-Jacques E. Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Nonlinear Systems Laboratory Slotine, Jean-Jacques E. Previous explanations of computations performed by recurrent networks have focused on symmetrically connected saturating neurons and their convergence toward attractors. Here we analyze the behavior of asymmetrical connected networks of linear threshold neurons, whose positive response is unbounded. We show that, for a wide range of parameters, this asymmetry brings interesting and computationally useful dynamical properties. When driven by input, the network explores potential solutions through highly unstable ‘expansion’ dynamics. This expansion is steered and constrained by negative divergence of the dynamics, which ensures that the dimensionality of the solution space continues to reduce until an acceptable solution manifold is reached. Then the system contracts stably on this manifold towards its final solution trajectory. The unstable positive feedback and cross inhibition that underlie expansion and divergence are common motifs in molecular and neuronal networks. Therefore we propose that very simple organizational constraints that combine these motifs can lead to spontaneous computation and so to the spontaneous modification of entropy that is characteristic of living systems. 2015-02-17T16:12:08Z 2015-02-17T16:12:08Z 2015-01 2014-09 Article http://purl.org/eprint/type/JournalArticle 1553-7358 1553-734X http://hdl.handle.net/1721.1/94559 Rutishauser, Ueli, Jean-Jacques Slotine, and Rodney Douglas. “Computation in Dynamically Bounded Asymmetric Systems.” Edited by Olaf Sporns. PLoS Comput Biol 11, no. 1 (January 24, 2015): e1004039. https://orcid.org/0000-0002-7161-7812 en_US http://dx.doi.org/10.1371/journal.pcbi.1004039 PLOS Computational Biology Creative Commons Attribution http://creativecommons.org/licenses/by/4.0/ application/pdf Public Library of Science Public Library of Science
spellingShingle Rutishauser, Ueli
Douglas, Rodney J.
Slotine, Jean-Jacques E.
Computation in Dynamically Bounded Asymmetric Systems
title Computation in Dynamically Bounded Asymmetric Systems
title_full Computation in Dynamically Bounded Asymmetric Systems
title_fullStr Computation in Dynamically Bounded Asymmetric Systems
title_full_unstemmed Computation in Dynamically Bounded Asymmetric Systems
title_short Computation in Dynamically Bounded Asymmetric Systems
title_sort computation in dynamically bounded asymmetric systems
url http://hdl.handle.net/1721.1/94559
https://orcid.org/0000-0002-7161-7812
work_keys_str_mv AT rutishauserueli computationindynamicallyboundedasymmetricsystems
AT douglasrodneyj computationindynamicallyboundedasymmetricsystems
AT slotinejeanjacquese computationindynamicallyboundedasymmetricsystems