First noninvasive measurement of fast brain signals

Processing information in the brain is one of the most complex operations in the human body. Disruptions in this processing often result in serious neurological diseases. Investigating how signals are transmitted inside the brain is therefore the key to a better understanding of various diseases. Our brains process information via slow and fast brain currents. To examine fast currents, it has, however, been necessary to introduce electrodes into the brain to date. Researchers from the Charité – Universitätsmedizin Berlin (one of Europe’s largest university hospitals) and from PTB have now succeeded in making these fast brain signals visible from the outside for the first time through using magnetoencephalography (MEG). They have furthermore observed a surprising variability. For this purpose, they used a particularly sensitive sensor system.

By electrically stimulating an arm nerve in four healthy subjects, the team of researchers showed that the new instrument is indeed able to detect fast brain currents magnetically. The MEG sensor, which was positioned directly above the brain area concerned, measured fast brain currents that were generated following this stimulation. Although the stimulation was always constant, the stimulus response changed from one stimulus to the next. Comparing each of these individual stimulus responses will open up the possibility for researchers to gain a deeper understanding of neurological diseases and to improve treatment.