Title :
Measurement and source estimation of MEG activities associated with a delayed-match paradigm
Author :
NAKAGAWA, Seiji ; Ueno, Shoogo ; Yamanami, Kenji ; Iwaki, Satoshi ; Ueno, Kenichi ; Imada, Toshiaki
Author_Institution :
Dept. of Biomed. Eng., Tokyo Univ., Japan
fDate :
30 Oct-2 Nov 1997
Abstract :
Visually evoked magnetoencephalograms (MEGs) associated with a delayed-match paradigm were measured to obtain functional information related to short-term memory processes. A delayed-match paradigm was introduced. The paradigm consists of a four-color-stimuli; a pair of circles with four differently-colored regions. The subjects retain the first image (Sample) until the second image (Test) appears. The MEGs were measured by a 122-channel whole-head-type SQUID system. A DC-like slow wave was observed at the period between latencies of 900 and 1500 msec during the short-term memory task. The source localization of the DC-like slow wave was estimated. The estimated sources were localized either in the occipital or postero-temporal region
Keywords :
magnetoencephalography; medical signal processing; neurophysiology; parameter estimation; DC-like slow wave; MEG activities; delayed-match paradigm; differently-colored regions; four-color-stimuli; functional information; occipital region; pair of circles; postero-temporal region; short-term memory processes; source estimation; source localization; vertical EOG; visually evoked magnetoencephalograms; whole-head-type SQUID system; Biomedical measurements; Delay estimation; Eyes; Fingers; Humans; Magnetic field measurement; Magnetic shielding; Monitoring; SQUIDs; Testing;
Conference_Titel :
Engineering in Medicine and Biology Society, 1997. Proceedings of the 19th Annual International Conference of the IEEE
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-4262-3
DOI :
10.1109/IEMBS.1997.756593
