title: Computing the center of mass for traveling alpha waves in the human brain.
abstract: The phenomenon of traveling waves of the brain is an intriguing area of research, and its mechanisms and neurobiological bases have been unknown since the 1950s. The present study offers a new method to compute traveling alpha waves using the center of mass algorithm. Electroencephalographic alpha waves are oscillations with a characteristic frequency range and reactivity to closed eyes. Several lines of evidence derived from qualitative observations suggest that the alpha waves represent a spreading wave process with specific trajectories in the human brain. We found that during a certain alpha wave peak recorded with 30 electrodes the trajectory starts and ends in distinct regions of the brain, mostly frontal-occipital, frontal-frontal, or occipital-frontal, but the position of the trajectory at the time in which the maximal positivity of the alpha wave occurs has a definite position near the central regions. Thus we observed that the trajectory always crossed around the central zones, traveling from one region to another region of the brain. A similar trajectory pattern was observed for different alpha wave peaks in one alpha burst, and in different subjects, with a mean velocity of 2.1+/-0.29 m/s. We found that all our results were clear and reproducible in all of the subjects. To our knowledge, the present method documents the first explicit description of a spreading wave process with a singular pattern in the human brain in terms of the center of mass algorithm.
authors.affiliation: Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, Col. San Manuel, Apartado Postal 406, Puebla, Pue. CP 72570, Mexico. emanjar@siu.buap.mx
authors.forename: Elías
authors.initials: E
authors.lastname: Manjarrez
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vázquez
authors.forename: Amira
authors.initials: A
authors.lastname: Flores
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000465:Algorithms; D000513:Alpha Rhythm / Q000295:instrumentation / Q000379:methods*; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology; D003198:Computer Simulation; D004566:Electrodes / Q000592:standards; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D009474:Neurons / Q000502:physiology