title: Improved measurement of intersession latency in mfVEPs.
abstract: OBJECTIVE
  The purpose of the study is to present a method (Selfcorr) by which to measure intersession latency differences between multifocal VEP (mfVEP) signals.
  
  
  METHODS
  The authors compared the intersession latency difference obtained using a correlation method (Selfcorr) against that obtained using a Template method. While the Template method cross-correlates the subject's signals with a reference database, the Selfcorr method cross-correlates traces across subsequent recordings taken from the same subject.
  
  
  RESULTS
  The variation in latency between intersession signals was 0.8 ± 13.6 and 0.5 ± 5.0 ms for the Template and Selfcorr methods, respectively, with a coefficient of variability CV_TEMPLATE = 15.83 and CV_SELFCORR = 5.68 (n = 18, p = 0.0002, Wilcoxon). The number of analyzable sectors with the Template and Selfcorr methods was 36.7 ± 8.5 and 45.3 ± 8.7, respectively (p = 0.0001, paired t test, two tailed).
  
  
  CONCLUSIONS
  The Selfcorr method produces smaller intersession mfVEP delays and variability over time than the Template method.
authors.affiliation: Biomedical Engineering Research Group, Department of Electronics, University of Alcalá, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: De Santiago
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.forename: R
authors.initials: R
authors.lastname: Blanco
authors.forename: C
authors.initials: C
authors.lastname: Pérez-Rico
authors.forename: J M
authors.initials: JM
authors.lastname: Rodríguez-Ascariz
authors.forename: R
authors.initials: R
authors.lastname: Barea
authors.forename: J M
authors.initials: JM
authors.lastname: Miguel-Jiménez
authors.forename: C
authors.initials: C
authors.lastname: Amo
authors.forename: E M
authors.initials: EM
authors.lastname: Sánchez-Morla
authors.forename: L
authors.initials: L
authors.lastname: Boquete
mesh_terms: D000328:Adult; D004594:Electrophysiology / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D055815:Young Adult