PMID- 9593893
OWN - NLM
STAT- MEDLINE
DCOM- 19980803
LR  - 20190614
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 791
IP  - 1-2
DP  - 1998 Apr 27
TI  - Serial processing of the somesthetic information revealed by different effects of 
      stimulus rate on the somatosensory-evoked potentials and magnetic fields.
PG  - 200-8
AB  - In order to evaluate information processing in the somatosensory cortex, the 
      effect of two different stimulus rates was investigated by simultaneously 
      recording somatosensory-evoked potentials (SEPs) and magnetic fields (SEFs) in 
      nine healthy adults. During electric stimulation of the median nerve at the 
      wrist, SEFs were recorded with the helmet-shaped whole-head coverage magnetometer 
      array with 122 first-order planar gradiometers while SEPs were simultaneously 
      recorded from seven scalp positions. Interstimulus intervals (ISIs) of 0.9 s and 
      4 s were compared. In all subjects, N20 as well as its magnetic counterpart, 
      N20m, was clearly demonstrated over the contralateral somatosensory area. 
      Subsequent deflections around 80-200 ms did not make any clear peak and were 
      smaller than those at 20-60 ms (P30m, P40m, N50m and P60m). After 200 ms, SEFs 
      were negligible, whereas SEPs had larger amplitude than those of shorter 
      latencies, constituting a peak around 250 ms (P250). Both SEF and SEP deflections 
      later than 40 ms were decreased in responses at the shorter ISI; this diminution 
      was most prominent for P250. Therefore, it is concluded that the tangential 
      currents in the somatosensory cortex (area 3b) mainly contribute to responses 
      during the first 200 ms after the stimulus, whereas the radially oriented 
      currents (most likely in the crown of the postcentral gyrus) take over for 
      subsequent information processing.
CI  - Copyright 1998 Elsevier Science B. V.
FAU - Nagamine, T
AU  - Nagamine T
AD  - Department of Brain Pathophysiology, Kyoto University School of Medicine, Kyoto 
      606-01, Japan.
FAU - Makela, J
AU  - Makela J
FAU - Mima, T
AU  - Mima T
FAU - Mikuni, N
AU  - Mikuni N
FAU - Nishitani, N
AU  - Nishitani N
FAU - Satoh, T
AU  - Satoh T
FAU - Ikeda, A
AU  - Ikeda A
FAU - Shibasaki, H
AU  - Shibasaki H
LA  - eng
PT  - Clinical Trial
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
SB  - IM
MH  - Adult
MH  - Electric Stimulation
MH  - *Electroencephalography
MH  - Evoked Potentials, Somatosensory/*physiology
MH  - Humans
MH  - *Magnetoencephalography
MH  - Male
MH  - Mental Processes/*physiology
MH  - Perception/*physiology
MH  - Reaction Time/physiology
MH  - Reference Values
EDAT- 1998/06/19 00:00
MHDA- 1998/06/19 00:01
CRDT- 1998/06/19 00:00
PHST- 1998/06/19 00:00 [pubmed]
PHST- 1998/06/19 00:01 [medline]
PHST- 1998/06/19 00:00 [entrez]
AID - S0006-8993(98)00095-X [pii]
AID - 10.1016/s0006-8993(98)00095-x [doi]
PST - ppublish
SO  - Brain Res. 1998 Apr 27;791(1-2):200-8. doi: 10.1016/s0006-8993(98)00095-x.