MACRODYNAMICS OF ELECTRICAL ACTIVITY IN THE WHOLE BRAIN

The general problem of brain mechanisms involved in perception can now be studied directly by means of new analysis–methods for the activity of large population of neurons. These methods range from indirect means of measuring changes in cerebral blood flow in local regions of the human cortex (functional magnetic resonance imaging, fMRI), or changes in the electrical activity of the human brain with EEG-recording with topological distributed macroelectrodes, to the use of chronically implanted multiple microelectrodes in primates. fMRI has the disadvantage of low temporal resolution and with multiple microelectrodes long distance measurements cannot yet be properly performed. Accordingly, recording of macro-activity (EEG/ERP or MEG) with a time resolution of millisecond-range is the most possibly adequate method to measure the dynamic properties of memory and the integrative brain function. Since neuroscientists have come to the general conclusion that large numbers of different brain regions have to coop...