Magnetoencephalography in the study of human somatosensory cortical processing

Magnetoencephalography (MEG) is a totally non-invasive research method whic h provides information about cortical dynamics on a millisecond time-scale. Whole-scalp magnetic field patterns following stimulation of different per ipheral nerves indicate activation of an extensive cortical network. At the SI cortex, the responses reflect mainly the activity of area 3b, with clea rly somatotopical representations of different body parts. The SII cortex i s activated bilaterally and it also receives, besides tactile input, nocice ptive afference. Somatically evoked MEG signals may also be detected from t he posterior parietal cortex, central mesial cortex and the frontal lobe. T he serial versus parallel processing in the cortical somatosensory network is still under debate.