Aa. Ioannides et al., ACTIVATION SEQUENCE OF DISCRETE BRAIN-AREAS DURING COGNITIVE-PROCESSES - RESULTS FROM MAGNETIC-FIELD TOMOGRAPHY, Electroencephalography and clinical neurophysiology, 91(5), 1994, pp. 399-402
Magnetic field tomography is a technique for extracting 3-dimensional
estimates of current density in the brain, from non-contact, non-invas
ive measurements of the magnetic field generated by the brain. It allo
ws visualisation of both cortical and subcortical focal activation pat
terns at millisecond intervals, and the relative time difference betwe
en active cortical areas. We have used this technique to study the act
ivation history of discrete brain regions associated with the preparat
ion for, initiation and inhibition of movement, and movement itself in
a CNV paradigm. The strongest focal activities are found within well
defined cortical regions, namely the auditory (A1), sensorimotor (SMI)
, medial parietal area (MPA) and anterior supplementary motor area (SM
A). For the movement condition, activation history differs for the war
ning stimulus and the stimulus initiating movement.