Tomographic electroencephalography/magnetoencephalography. Dynamics of human neural network switching.
New developments in multimodal registration of electroencephalography (EEG), magnetic resonance imaging (MRI), and positron emission tomography (PET) are presented as a method to create a tomographic EEG. Three-dimensional information about the x,y,z location of the sources of event-related potentials is corroborated through the use of experimental design and coregistration with MRI and PET. Once the three-dimensional location of event-related potential dipole sources is identified and corroborated, pseudoinverse procedures are used to derive a new EEG voltage sequence from each of the dipoles. Each derived EEG dipole time series is analogous to recording EEG from a deeply implanted electrode and constitutes a four-dimensional tomographic EEG (i.e., three-dimensional space plus time). EEG coherence and phase analyses are then performed on the dipole-derived time series to study the temporal and spatial dynamics of neural network switching during voluntary finger movements. The purpose of this article is to demonstrate a new method to exploit the time domain dynamics of neural network switching in behaving human subjects.
Thatcher
R W
RW
Neurology and Medical Research Services, Veterans Administration Medical Center Bay Pines, FL 33504.
D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D005385:Fingers / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D009048:Motor Skills / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*; D013997:Time Factors; D014055:Tomography, Emission-Computed