Synchronous neural interactions assessed by magnetoencephalography: a functional biomarker for brain disorders.
Georgopoulos AP,
Karageorgiou E,
Leuthold AC,
Lewis SM,
Lynch JK,
Alonso AA,
Aslam Z,
Carpenter AF,
Georgopoulos A,
Hemmy LS,
Koutlas IG,
Langheim FJ,
McCarten JR,
McPherson SE,
Pardo JV,
Pardo PJ,
Parry GJ,
Rottunda SJ,
Segal BM,
Sponheim SR,
Stanwyck JJ,
Stephane M,
Westermeyer JJ.
Brain Sciences Center, Veterans Affairs Medical Center, Minneapolis, MN 55417, USA. omega@umn.edu
We report on a test to assess the dynamic brain function at high temporal resolution using magnetoencephalography (MEG). The essence of the test is the measurement of the dynamic synchronous neural interactions, an essential aspect of the brain function. MEG signals were recorded from 248 axial gradiometers while 142 human subjects fixated a spot of light for 45-60 s. After fitting an autoregressive integrative moving average (ARIMA) model and taking the stationary residuals, all pairwise, zero-lag, partial cross-correlations (PCC(ij)(0)) and their z-transforms (z(ij)(0)) between i and j sensors were calculated, providing estimates of the strength and sign (positive, negative) of direct synchronous coupling at 1 ms temporal resolution. We found that subsets of z(ij)(0) successfully classified individual subjects to their respective groups (multiple sclerosis, Alzheimer's disease, schizophrenia, Sjögren's syndrome, chronic alcoholism, facial pain, healthy controls) and gave excellent external cross-validation results.
PMID: 18057502 [PubMed - indexed for MEDLINE]