Neuroinformatics

, Volume 3, Issue 4, pp 301–313 | Cite as

Phase synchronization measurements using electroencephalographic recordings

What can we really say about neuronal synchrony?
  • Ramón Guevara
  • José Luis Pérez Velazquez
  • Vera Nenadovic
  • Richard Wennberg
  • Goran Senjanović
  • Luís Garcia Dominguez
Original Article

Abstract

Phase synchrony analysis is a relatively new concept that is being increasingly used on neurophysiological data obtained through different methodologies. It is currently believed that phase synchrony is an important signature of information binding between distant sites of the brain, especially during cognitive tasks. Electroencephalographic (EEG) recordings are the most widely used recording technique for recording brain signals and assessing phase synchrony patterns. In this study, we address the suitability of phase synchrony analysis in EEG recordings. Using geometrical arguments and numerical examples, employing EEG and magnetoencephalographic data, we show that the presence of a common reference signal in the case of EEG recordings results in a distortion of the synchrony values observed, in that the amplitudes of the signals influence the synchrony measured, and in general destroys the intended physical interpretation of phase synchrony.

Index Entries

Electroencephalographic recordings magnetoencephalographic recordings phase synchronization reference electrode bipolar signal 

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Copyright information

© Humana Press Inc 2005

Authors and Affiliations

  • Ramón Guevara
    • 1
  • José Luis Pérez Velazquez
    • 2
    • 3
  • Vera Nenadovic
    • 4
  • Richard Wennberg
    • 5
  • Goran Senjanović
    • 1
  • Luís Garcia Dominguez
    • 2
    • 3
  1. 1.Abdus Salam ICTPMiaramare, TriesteItaly
  2. 2.Departments of Paediatrics and Institute of Medical ScienceUniversity of TorontoTorontoCanada
  3. 3.Brain and Behaviour Programme, Division of Neurologythe Hospital for Sick ChildrenTorontoCanada
  4. 4.Department of Critical CareThe Hospital for Sick ChildrenTorontoCanada
  5. 5.Toronto Western Hospital, Krembil Neuroscience Centre, Division of NeurologyUniversity of TorontoTorontoCanada

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