title: The assessment of reliability of cognitive evoked potential in normal person.
abstract: OBJECTIVE
  To evaluate intra-tester reliability of P300 more precisely, this study was designed. Event-related potential (ERP) is the result of endogenous brain response following cognitive stimulus. The P300 component of the human ERP is a positive wave with a latency of 300 ms or greater. Our purpose of this study was to estimate reliability of P300 latency and amplitude with 30 normal persons without head injury, as well as to set up them as the reference values in the event that they would be found to be highly reliable.
  
  
  METHODS
  ERP was performed at three separate times on 30 normal adults in their 20s and 30s. We measured P300 latency and amplitude among ERP.
  
  
  RESULTS
  P300 latency show excellent reliability with intraclass correlation coefficient (ICC) of 0.81. As to P300 amplitude, reliability was good to fair with ICC of 0.53. Average value of P300 latency was 311.3±37.0 ms, shorter than reference value of previous study in Korea.
  
  
  CONCLUSIONS
  P300 latency revealed higher reliability than P300 amplitude, although reliability of P300 was confirmed in both component. After further study including precise mechanism, influence factor on measurement and method standardization, it is expected to be an objective indicator to assess the cognitive state and predict prognosis.
authors.affiliation: Department of Rehabilitation Medicine and Rehabilitation, Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Seong
authors.initials: JS
authors.lastname: Hong
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Yeo Hoon
authors.initials: YH
authors.lastname: Yoon
authors.forename: Jung Hwa
authors.initials: JH
authors.lastname: Choi
authors.forename: Jae Eun
authors.initials: JE
authors.lastname: Shin
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Kim
authors.forename: Yoon Ghil
authors.initials: YG
authors.lastname: Park
keywords: Event-related potentials; P300 component; Reliability