The neural origin generating early cortical components of SEP: Topographical analysis using temporal-second-order-differentiation of cortical SEPs

Jun Namiki, Moriichirou Takase, Takayuki Ohira, Kazuhiro Goto, Mami Ishikawa, Yasuhiko Ajimi, Shigeo Toya

Research output: Contribution to journalArticle

8 Citations (Scopus)


In order to identify dipole generators of the N20/P20 and P25, we employed second-order-differentiation in the temporal dimension (temporal-second-order-differentiation; TSOD) with Δt = 2 msec. The rate of variation in the voltage of cortical SEPs calculated by TSOD identified responses of each dipole, reflecting the density of neuronal firing. On topographic analysis, the distributions of N20/P20 and P25 conformed to the shape of gyrus better in the TSOD maps than in the isovoltage maps. The TSOD maps indicated that N20 and P25 were post-central components and that P20 was a pre-central one. Therefore, we concluded that the two dipoles generating N20/P20 and P25 were located in the posterior wall of the central sulcus (area 3b) and the crown (areas 1 and 2) of the post-central gyrus, respectively.

Original languageEnglish
Pages (from-to)229-232
Number of pages4
JournalBrain Topography
Issue number3
Publication statusPublished - 1996 May 24



  • Central sulcus
  • Dipoles
  • Neural origin
  • SEP
  • Second order differentiation
  • Topography

ASJC Scopus subject areas

  • Anatomy
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Clinical Neurology

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