 |
| Research article summary (published 30 May 2002): |
Characterizing instantaneous phase relationships in whole-brain fMRI activation data.
Full Abstract
Typically, fMRI data is processed in the time domain with linear methods such as regression and correlation analysis. We propose that the theory of phase synchronization may be used to more completely understand the dynamics of interacting systems, and can be applied to fMRI data as a novel method of detecting activation. Generalized synchronization is a phenomenon that occurs when there is a nonlinear functional relationship present between two or more coupled, oscillatory systems, whereas phase synchronization is defined as the locking of the phases while the amplitudes may vary. In this study, we developed an application of phase synchronization analysis that is appropriate for fMRI data, in which the phase locking condition is investigated between a voxel time series and the reference function of the task performed. A synchronization index is calculated to quantify the level of phase locking, and a nonparametric permutation test is used to determine the statistical significance of the results. We performed the phase synchronization analysis on the data from five volunteers for an event-related finger-tapping task. Functional maps were created that provide information on the interrelations between the instantaneous phases of the reference function and the voxel time series in a whole-brain fMRI activation data set. We conclude that this method of analysis is useful for revealing additional information on the complex nature of the fMRI time series.Copyright 2002 Wiley-Liss, Inc.
Learn Faster Today Improve your study skills
Author information
Author/s: Laird, Angela R (AR); Rogers, Baxter P (BP); Carew, John D (JD); Arfanakis, Konstantinos (K); Moritz, Chad H (CH); Meyerand, M Elizabeth (ME);
Affiliation: Department of Physics, University of Wisconsin, Madison, Wisconsin, USA. laird(-atsign-)mr.radiology.wisc.edu
Journal and publication information
Publication Type: Journal Article
Journal: Human brain mapping (Hum Brain Mapp), published in United States. (Language: eng)
Reference: 2002-Jun; vol 16 (issue 2) : pp 71-80
Dates: Created 2002/04/15; Completed 2002/07/26; Revised 2007/11/15;
PMID: 11954057, status: MEDLINE (last retrieval date: 11/6/2008)
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
External Links for this article (including full text providers, if available):
Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.
This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.
MeSH headings (categories)
This article was linked to the MESH Headings shown below.
|
|
Related articles
This article has not been indexed for related articles as yet, however you can still use the live related article search links below.
See a large map of 100+ related articles.