title: Latency correction of event-related potentials between different experimental protocols.
abstract: OBJECTIVE
  A fundamental issue in EEG event-related potentials (ERPs) studies is the amount of data required to have an accurate ERP model. This also impacts the time required to train a classifier for a brain-computer interface (BCI). This issue is mainly due to the poor signal-to-noise ratio and the large fluctuations of the EEG caused by several sources of variability. One of these sources is directly related to the experimental protocol or application designed, and may affect the amplitude or latency of ERPs. This usually prevents BCI classifiers from generalizing among different experimental protocols. In this paper, we analyze the effect of the amplitude and the latency variations among different experimental protocols based on the same type of ERP.
  
  
  METHODS
  We present a method to analyze and compensate for the latency variations in BCI applications. The algorithm has been tested on two widely used ERPs (P300 and observation error potentials), in three experimental protocols in each case. We report the ERP analysis and single-trial classification.
  
  
  RESULTS
  The results obtained show that the designed experimental protocols significantly affect the latency of the recorded potentials but not the amplitudes.
  
  
  CONCLUSIONS
  These results show how the use of latency-corrected data can be used to generalize the BCIs, reducing the calibration time when facing a new experimental protocol.
authors.affiliation: Instituto de Investigación en Ingeniería de Aragón (I3A), Edificio I+D+i, Mariano Esquillor, E-50018 Zaragoza, Spain. Departamento de Informática e Ingeniería de Sistemas (DIIS), Universidad de Zaragoza, Maria de Luna 1, E-50018 Zaragoza, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Iturrate
authors.forename: R
authors.initials: R
authors.lastname: Chavarriaga
authors.forename: L
authors.initials: L
authors.lastname: Montesano
authors.forename: J
authors.initials: J
authors.lastname: Minguez
authors.forename: JdR
authors.initials: J
authors.lastname: Millán
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D062207:Brain-Computer Interfaces; D003627:Data Interpretation, Statistical; D004569:Electroencephalography / Q000379:methods*; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014793:Visual Cortex / Q000502:physiology*