Validity of spectral analysis of evoked potentials in brain research


Kramarenko A., Tan U.

INTERNATIONAL JOURNAL OF NEUROSCIENCE, cilt.112, sa.4, ss.489-499, 2002 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 112 Sayı: 4
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1080/00207450290025608
  • Dergi Adı: INTERNATIONAL JOURNAL OF NEUROSCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.489-499
  • Karadeniz Teknik Üniversitesi Adresli: Hayır

Özet

The averaged electronencephologram (EEG) response of the brain to an external stimulus (evoked potential, EP) is usually subjected to spectral analysis using the fast Fourier transform (FFT), especially to discover the relation of cognitive ability to so-called brain dynamics. There is indeed a discrepancy between these two systems, because the brain is a highly complex nonlinear system, analyzed by a linear system (FFT). We present in this work some inaccuracies that occurred when EPs are subjected to spectral analysis, using a model signal. First of all, the EP power spectra depended upon the number of samples used for averaging; the input EP (model signal) and the output EP (from the system) seemed to be similar in forms, but they exhibited completely different spectral power curves. It was concluded that the spectral analysis of evoked responses by using FFT (linear system analysis) in relation to brain (highly complex nonlinear system) may mislead neuroscientists.