DOI: 10.14704/nq.2014.12.1.700

Lag Synchronisation in the Human Brain: Evidence from 17,722 Healthy Subjects’ EEG Analyses

Oldrich Vysata, Jaromir Kukal, Martin Valis, Ladislav Pazdera, Jakub Hort, Ales Prochazka


Lag synchronisation of two different chaotic oscillators is phenomenon when the signal from the system with a lower frequency has some delay with respect to the system which has the higher frequency. The interaction among the multiple brain oscillators may produce such a phenomena. The purpose of this study was to determine if direction of phase difference between two channels in EEG does depend on the source characteristic frequency. Independence of phase shift on mean frequency between two channels was tested on group of 30112 healthy truck drivers. Mean phase difference between two EEG channels was estimated by Hilbert transform and compared to the difference of characteristic frequency. Number of EEG segments with the phase delay from the electrode with a lower frequency to the electrode with a higher frequency was significantly higher then to the electrode with lower frequency. The most significant direction of phase delay was fronto-occipital. The results support hypothesis about presence of lag synchronization in the brain. This work provides alternative explanation of the phase shift between oscillations in different part of the brain.


Lag synchronisation; Electroencephalography; Characteristic frequency; Chaotic neural oscillators

Full Text:

Full Text PDF


Baier G, Leder R, Parmananda P. Human electroencephalogram induces transient coherence in excitable spatiotemporal chaos. Phys Rev Lett 2000;84:4501.

Buzsáki G. Rhythms of the Brain, New York:Oxford University Press, 2006.

Chen Y, Chen XX, Gu SS. Lag synchronization of structurally nonequivalent chaotic systems with time delays. Nonlinear Anal 2007;66:1929-1937.

Lehmann D, Faber PL, Gianotti LRR, Kochi K, Pascual-Marqui RD. Coherence and phase locking in the scalp EEG and between LORETA model sources, and microstates as putative mechanisms of brain temporo-spatial functional organization. J Physiol 2006; 99:29-36.

Nolte G, Wheaton OBL, Mari Z, Vorbach S, Hallett M. Identifying true brain interaction from EEG data using the imaginary part of coherency. Clin Neurophysiol 2004; 115:2292-2307.

Oppenheim AV, and Schafer RW. Discrete-Time Signal Processing, 2nd ed., Prentice-Hall, 1998

Roelfsema PR, Engel AK, Konig P, Singer W. Visuomotor integration is associated with zero time-lag synchronization among cortical areas. Nature 1997; 385:157-161.

Rosenblum MG, Pikovsky AS, Kurths J. From Phase to Lag Synchronization in Coupled Chaotic Oscillators. Phys Rev Lett 1997; 78:4193-4196.

Rosenblum MG, Pikovsky AS, Kurths J. Phase synchronization of chaotic oscillators. Phys Rev Lett 1996;76:1804-1807. ttp://

Sanei S, Adaptive Processing of Brain Signals. John Wiley & Sons, 2013.

Stam CJ, Nolte G, Daffertshofer A. Phase Lag Index: Assessment of Functional Connectivity From Multi Channel EEG and MEG With Diminished Bias From Common Sources. Hum Brain Mapp 2007; 28:1178-1193.

Stam CJ, van Cappellen van Walsum AM, Pijnenburg Yolande AL, Berendse HW, de Munck JC, Scheltens P. Generalized Synchronization of MEG Recordings in Alzheimer's Disease: Evidence for Involvement of the Gamma Band. J Clin Neurophysiol 2002;19:562-574.

Sweeney-Reed CM and Nasuto SJ. A novel approach to the detection of synchronisation in EEG based on empirical mode decomposition. J Comput Neurosci 2007; 23:79-111.

Taherion S, Lai YC. Observability of lag synchronization of coupled chaotic oscillators. Phys Rev E 1999;59:6247-6250.

Tallon-Baudry C, Betrand O, Fischer C. Oscillatory synchrony between human extrastriate areas during visual shortterm memory maintenance. J Neurosci 2001; 21:1-5.

Yi-Wen Liu. Hilbert Transform and Applications, Fourier Transform Applications, Dr Salih Salih (Ed.), 2012.

Supporting Agencies

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

| NeuroScience + QuantumPhysics> NeuroQuantology :: Copyright 2001-2019