Intermittent vorticity, power spectral scaling and dynamical measures on resting brain magnetic field fluctuations

A new time-dependent global MEG variable, symmetric sensor difference series, from frontal, central, parietal and temporal sensor pairs in ten task free, resting schizophrenic patients and ten age and sex matched controls were studied using Morlet wavelet transformations of the leading eigenfunctions of correlation-time-lagged auto-covariance matrices, power spectral scaling indices, topological and metric entropies, unwinding numbers, leading Lyapounov exponents, capacity dimension, high moments and a product-measure order parameter, measureable entropy manifold volume, memv.

A new dynamical object with longest time scales in tens of seconds, the strudel, intermittent incidents of simultaneously hierarchical vorticity, was found in the wavelet graphs. Speculation arises that strudels may be concomitants of “task unrelated thoughts” or daydreaming. In this pilot study, episodes of absent and decreased strudel density and statistically significant lower values of memv and the other entropy-complexity measures were observed in schizophrenic patients compared with controls.

The article was published in: The dynamic brain Oxford University Press Oxford. 296-337.

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This work was supported (in part) by the Fetzer Franklin Fund of the John E. Fetzer Memorial Trust.