A critical note on the definition of phase-amplitude cross-frequency coupling

J Neurosci Methods. 2011 Oct 15;201(2):438-43. doi: 10.1016/j.jneumeth.2011.08.014. Epub 2011 Aug 17.


Recent studies have observed the ubiquity of phase-amplitude coupling (PAC) phenomenon in human and animal brain recordings. While various methods were performed to quantify it, a rigorous analytical definition of PAC is lacking. This paper yields an analytical definition and accordingly offers theoretical insights into some of the current methods. A direct PAC estimator based on the given definition is presented and shown theoretically to be superior to some of the previous methods such as general linear model (GLM) estimator. It is also shown that the proposed PAC estimator is equivalent to GLM estimator when a constant term is removed from its formulation. The validity of the derivations is demonstrated with simulated data of varying noise levels and local field potentials recorded from the subthalamic nucleus of a Parkinson's disease patient.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology*
  • Animals
  • Disease Models, Animal
  • Electrophysiology / methods*
  • Electrophysiology / standards
  • Humans
  • Neurons / pathology
  • Parkinson Disease / pathology
  • Parkinson Disease / physiopathology
  • Parkinson Disease / therapy
  • Reaction Time / physiology
  • Reproducibility of Results
  • Signal Processing, Computer-Assisted*
  • Subthalamic Nucleus / cytology
  • Subthalamic Nucleus / pathology
  • Time Factors