RECONSTRUCTION OF THE SPATIOTEMPORAL DYNAMICS OF A HUMAN MAGNETOENCEPHALOGRAM

We reconstruct the entire experimentally observed spatio-temporal sign al of a human magnetoencephalogram (MEG) observed in a sensori-motor-c oordination experiment by Kelso et al. In this experiment, when an aco ustic stimulus frequency is changed systematically, a spontaneous tran sition in coordination occurs at a critical frequency in both the moto r behavior and brain signals. Here we present a stepwise approach for the reconstruction of the spatio-temporal signal: First, we identify t he order parameters and recall a theoretical model by the present auth ors and Kelso which reproduces the temporal dynamics of the order para meters. Second, we use the variational method by Uhl et al. in order t o determine the spatial modes of the order parameters. Third, we prese nt a variational method for the reconstruction of the remaining spatio -temporal signal and determine the spatial modes and temporal dynamics of the enslaved variables and possible order parameter modifications. The obtained set of spatial modes proves to be a fixed spatial base s ystem of the observed temporal dynamics in the brain.