Partial Spectroscopy of the Human Brain Based On the Joint Analysis of MEG and MRI Data. Application to the CamCAN Data Array

The new technology was developed to calculate spectral characteristics of various compartments of the human brain. This technology combines two types of spatial data: 1) MEG-based functional tomogram presenting spatial distribution of the electric sources and 2) anatomical structure of the brain estimated by the magnetic resonance imaging. Multichannel magnetoencephalograms were used to calculate the functional tomogram by the precise frequency-pattern analysis, decomposing brain activity into a set of elementary oscillations. In the functional tomogram, unique spatial location corresponds to each spectral component, generated by the equivalent current dipole. Based on this fact, we calculated partial spectra – sets of frequencies, generated by various anatomical regions of the brain. Individual spatial structure of the brain compartments was determined by the annotated segmentation of magnetic resonance tomogram for each subject under study. The partial spectrum of the brain compartment was composed of the set of frequencies, localized into this compartment. Here we calculated partial spectra of 15 compartments of the brain for 600 subjects, using MEG and MRI datasets obtained from the open archive CamCAN. Average spectra were calculated and the distribution of the spectral power between brain compartments was estimated.