Non-linear electroencephalogram dynamics induced by magnetic stimulation

Non-linear electroencephalogram dynamics induced by magnetic stimulation (MS) were demonstrated using the brain potential map (BPM). The early evoked cortical activity was recorded at the right anterior scalp areas after MS of left hand muscle. Then, the activity shifted with time from the right anterior scalp areas to the right posterior scalp areas, to the left anterior scalp areas, to the left posterior scalp areas, respectively. The changes of evoked cortical activities lasted two periods, and during the interval between two periods negative evoked potentials were observed over the scalp. These results could show the spatio-temporal pattern in that information of the stimulus encoding could be processed in cortex