Title :
Source localization of auditory evoked magnetic fields during waking and sleep stages
Author :
Iramina, K. ; Ueno, S.
Author_Institution :
Dept. of Comput. Sci. & Commun. Eng., Kyushu Univ., Fukuoka, Japan
fDate :
11/1/1994 12:00:00 AM
Abstract :
We developed a high sensitive DC-SQUID system with a first-order gradiometer. This study focuses on the source location of brain electrical activities, in particular on the sources of auditory-evoked responses during sleep using magnetic field measurements by our SQUID system. We investigated the relationships between the sources of auditory evoked responses and sleep stages. Sources of N100 components, which appeared at about 100 msec after stimulation, and P200 components, which appeared at about 200 msec were estimated during waking and sleep stages. It was revealed that the sources of N100 and P200 components were different in each sleep stage. Sources of the N330 component, which appeared 330 msec after stimulation, were also investigated. Both MEG and EEG measurements made it clear that sources of the N330 component are modeled by multiple dipoles which diffuse in the cortex
Keywords :
auditory evoked potentials; bioelectric phenomena; biomagnetism; brain; electroencephalography; hearing; magnetoencephalography; 100 ms; 200 ms; 330 ms; EEG measurement; MEG measurement; N100 components; N330 component; P200 components; auditory evoked magnetic fields; brain; brain electrical activities; cortex; first-order gradiometer; high sensitive DC-SQUID system; magnetic field measurements; multiple dipoles; sleep stage; source localization; waking stage; Biomedical engineering; Brain; Computer science; Electroencephalography; Magnetic field measurement; Magnetic fields; Perpendicular magnetic recording; SQUIDs; Sleep; Surface topography;
Journal_Title :
Magnetics, IEEE Transactions on
