Skip to main content


We're creating a new version of this page. See preview

  • Poster presentation
  • Open Access

Physics of psychophysics: optimal dynamic range of critical excitable networks

BMC Neuroscience20078 (Suppl 2) :P174

  • Published:


  • Phase Transition
  • Ganglion Cell
  • Retinal Ganglion Cell
  • Neural Basis
  • Relevant Quantity

A recurrent idea in the study of complex systems is that optimal information processing is to be found near phase transitions [13]. However, this heuristic hypothesis has few (if any) concrete realizations where a standard and biologically relevant quantity is optimized at criticality. Here we give a clear example of such phenomenon: a network of excitable elements has its sensitivity and dynamic range maximized at the critical point of a nonequilibrium phase transition. Our results are compatible with the essential role of gap junctions in olfactory glomeruli and retinal ganglion cell output. Synchronization and global oscillations also emerge from the network dynamics. We propose that the main functional role of electrical coupling is to provide an enhancement of dynamic range, therefore allowing the coding of information spanning several orders of magnitude. The mechanism provides a microscopic neural basis for psychophysical laws.

Authors’ Affiliations

Laboratório de Física Teórica e Computacional, Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil
Departamento de Física e Matemática, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP, Brazil


  1. Langton CG: Computation at the edge of chaos: phase transitions and emergent computation. Physica D. 1990, 42: 12-37. 10.1016/0167-2789(90)90064-V.View ArticleGoogle Scholar
  2. Bak P: How nature works: the science of self-organized criticality. 1997, Oxford University Press, New YorkGoogle Scholar
  3. Chialvo D: Critical brain networks. Physica A. 2004, 340: 756-765. 10.1016/j.physa.2004.05.064.View ArticleGoogle Scholar


© Copelli and Kinouchi; licensee BioMed Central Ltd. 2007

This article is published under license to BioMed Central Ltd.