|
|
||||||||
The Journal of Neurophysiology Vol. 78 No. 6 December 1997,
pp. 3453-3459
Copyright ©1997 The American Physiological Society
Department of Basic Sciences, Medical School, University of Crete, 71110 Heraklion, Greece; and Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University, New York, New York 10032
Christakos, Constantinos N. On the detection and measurement of synchrony in large neural populations by coherence analysis. J. Neurophysiol. 78: 3453-3459, 1997. This study considers the possibility of using coherence analysis for detection and measurement of synchrony (correlations) in large neural populations, applied to activities that are relatively easy to record in parallel. Mathematical analysis and computer simulations are used to examine the behavior of the coherence function between both unitary and population-aggregate activity (UTA coherence) and the aggregate activities of two populations (ATA coherence). The results indicate that for a large population showing partial correlations, the UTA coherence function is almost zero at all frequencies for the uncorrelated units. However, unless the synchrony is very restricted, its value is nonzero (i.e., statistically significant by common criteria) at each frequency of synchrony for the units that show correlations to other units. Moreover, this value is indicative of the strength of synchrony for any given unit. These properties enable the identification of the correlated units in a sample of unit/population activities simultaneously recorded in a series of experiments, and hence the detection of synchrony. The extent of synchrony can then be estimated as the fraction of such units in the sample, whereas the values of the UTA coherences in the sample can be used to estimate the strength and its distribution within the population. Similarly, the ATA coherence function is generally nonzero (significant) at the frequencies where there are correlations between members of two large populations. This enables the easy detection of such correlations from simultaneously recorded population activities. However, this function is a very sensitive index of synchrony and even shows saturation effects. It may therefore be used as a general measure of synchrony only under restricted conditions.
This article has been cited by other articles:
![]() |
G. Schneider Messages of Oscillatory Correlograms: A Spike Train Model Neural Comput., May 1, 2008; 20(5): 1211 - 1238. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Erimaki and C. N. Christakos Coherent Motor Unit Rhythms in the 6-10 Hz Range During Time-Varying Voluntary Muscle Contractions: Neural Mechanism and Relation to Rhythmical Motor Control J Neurophysiol, February 1, 2008; 99(2): 473 - 483. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. Magill, A. Pogosyan, A. Sharott, J. Csicsvari, J. P. Bolam, and P. Brown Changes in functional connectivity within the rat striatopallidal axis during global brain activation in vivo. J. Neurosci., June 7, 2006; 26(23): 6318 - 6329. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. N. Christakos, N. A. Papadimitriou, and S. Erimaki Parallel Neuronal Mechanisms Underlying Physiological Force Tremor in Steady Muscle Contractions of Humans J Neurophysiol, January 1, 2006; 95(1): 53 - 66. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Cassidy, P. Mazzone, A. Oliviero, A. Insola, P. Tonali, V. D. Lazzaro, and P. Brown Movement-related changes in synchronization in the human basal ganglia Brain, June 1, 2002; 125(6): 1235 - 1246. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Nakazawa, A. R. Granata, and M. I. Cohen Synchronized Fast Rhythms in Inspiratory and Expiratory Nerve Discharges During Fictive Vocalization J Neurophysiol, March 1, 2000; 83(3): 1415 - 1425. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Erimaki and C. N. Christakos Occurrence of Widespread Motor-Unit Firing Correlations in Muscle Contractions: Their Role in the Generation of Tremor and Time-Varying Voluntary Force J Neurophysiol, November 1, 1999; 82(5): 2839 - 2846. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. V. TRANK, V. V. TURKIN, and T. M. HAMM Coherence between Locomotor Drive Potentials and Neurograms of Motor Pools with Variable Patterns of Locomotion Ann. N.Y. Acad. Sci., November 16, 1998; 860(1): 448 - 451. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |