Abstract

An essential role of a superconducting magnetic shield is described for study of higher function of human brains. The present SQUID has a sensitivity of 0.9 fT/(Hz)1/2 at 100 Hz in a superconducting magnetic shield. SQUID sensors are made of SNS (Superconductor/Normal metal/Superconductor) junctions. Recent theories of beamformer and MUSIC (multiple signal classification) emphasize the importance of SNR (signal-to-noise ratio) of data to locate equivalent current dipoles in brains. For instance, MUSIC uses the noise subspace of the covariant matrix practically calculated by measured magnetic fields. Dynamical responses of hippocampus to novelty or unexpectedness are measured by the SQUID system in a superconducting magnetic shield and visualized by swLORETA-an extension of sLORETA (standardized low-resolution electromagnetic tomography). The SQUID system in a magnetic shield of high-Tc superconductor is yielding new information of deep areas of human brains. The sensitivity of neuromagnetic SQUID measurements is proved to be limited by the system noise temperature of a SQUID hardware system but not so-called “brain noises”.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.