Functional Segregation of Parts of the “Sensorimotor Complex” of the Human Cerebral Cortex by Magnetoencephalography

• Published in: Neuroscience and behavioral physiology Vol. 45; no. 9; pp. 1068 - 1076
• Main Authors: Pron’ko, P. K., Prokofiev, A. O., Osadchii, A. E., Chernyshev, B. V., Stroganova, T. A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-11-2015; Springer Nature B.V
• Subjects: Behavioral Sciences; Biomedical and Life Sciences; Biomedicine; Brain; Cerebral cortex; Cortex (motor); Cortex (somatosensory); Fragmentation; Functional anatomy; Handedness; Magnetoencephalography; Motor task performance; Neurobiology; Neurosciences; Sensorimotor system; independent components analysis; actogram; magnetoencephalography; primary motor cortex
• ISSN: 0097-0549; 1573-899X
• DOI: 10.1007/s11055-015-0187-4

A method was developed for the noninvasive mapping of the primary motor cortex in humans. Magnetic responses evoked by repeated voluntary movements of the right index finger were studied in 18 healthy right-handed subjects. Finger movement periods were assessed using accelerometer signals. Continuous evoked brain magnetic activity recorded in the subjects throughout the experimental sessions was assembled into a single sequence which was then fragmented into independent components by independent components analysis and ranked in terms of the quantity of mutual information with the modified accelerometer signal. Averaging of the independent components demonstrating strongest links with finger movements was performed relative to the moment at which the movement started. Modeling of the distribution of the cerebral sources of the two independent components with the largest amounts of mutual information showed that their sources were located in the contralateral motor areas of the cortex, corresponding to anatomical markers of the hand representation area in the primary motor and primary somatosensory cortex. This method provided the fundamental ability to localize the M1 zone at the group level in healthy subjects.