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Influences of Different Electrode Positions on the Human Somatosensory Evoked Response
Author(s) -
IKUTA Takumi
Publication year - 1969
Publication title -
psychiatry and clinical neurosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.609
H-Index - 74
eISSN - 1440-1819
pISSN - 1323-1316
DOI - 10.1111/j.1440-1819.1969.tb01440.x
Subject(s) - scalp , somatosensory system , somatosensory evoked potential , electrophysiology , electroencephalography , neuroscience , evoked potential , cerebral cortex , stimulation , audiology , electrode , psychology , nuclear magnetic resonance , chemistry , physics , anatomy , medicine
Summary With the human Somatosensory Evoked Response (SER) evoked by the right median nerve stimulation and recorded on the scalp by an on‐line medical data processing computer, the influences of the different bipolar electrode positions on the SER were investigated. Setting 10 bipolar electrode positions on the parasagittal line on the scalp, 7 cm contralateral to the median nerve stimulated, 10 kinds of SERs with 10 different bipolar electrode positions were recorded. The patterns of these individual SERs were converted into the series of integers representing the pattern of the SER, and were subjected to the mathematical procedures by means of digital off‐line computer according to the schedule including the programs to calculate and plot the Inter‐Individual Averaged SER Pattern (IIA‐SER Pattern) , the Pattern of the Fourier Progression a and b of the IIA‐SER Pattern and other trials for some kinds of the Pattern Recognition. Results obtained were as follows:1 As the distance between bipolar electrodes increased, the amplitude of IIA‐SER Pattern , represented by the amplitude between the highest positive peak P 2 and the deepest negative peak N 4 tended to increase, and P 3 became recessive as represented by the amplitude between P 3 ‐N 3 . 2 The potential forming P 2 and N 4 ranged on relatively wide areas on the contralateral cerebral cortex, and the potential forming P 3 ranged in relatively restricted areas on the contralateral cerebral cortex with major potential grade in the frontal area. 3 Changes of other items, including latencies of the components of the SER according to the shift of the electrode position, and other trials for the Pattern Recognition were examined. 4 Consequently, the bipolar electrode setting on the points 4 cm anterior and 2 cm posterior to the midcoronal line, on the parasagittal line 7 cm contralateral to the median neve stimulated, is recommendable for the recording of SER.