Conventional
techniques for noninvasive measurement of brain function such as
electroencephalography (EEG), magnetoencephalography (MEG), functional magnetic
resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS) have
critical limitations of spatial or temporal resolution. Here, we developed a novel technique which
enables the precise measurement of dynamic brain signals and localized
identification of active brain regions. In this technique, termed as
magnetically biased field (MBF), human brain signal is measured as the
fluctuation of a transcranial static magnetic field emitted by a coil placed on
the scalp. The validity of MBF was confirmed by the measurement of
somatosensory evoked signals. Fast somatosensory evoked
signals were successfully observed. Localized maximum positive and negative
deflections appeared at the region which represents the right primary
somatosensory area contralateral to the stimulated hand. The ability of MBF to
detect dynamic brain activity precisely can have numerous applications such as
diagnosing brain diseases and brain-machine interfaces.
Novel Technique for Noninvasive Detection of Localized Dynamic Brain Signals by Using Transcranial Static Magnetic Fields
