Abnormal P600 word repetition effect in elderly persons with preclinical Alzheimer's disease

John M Olichney, Jamie Pak, David P. Salmon, Jin Chen Yang, Tim Gahagan, Ralph Nowacki, Lawrence Hansen, Douglas Galasko, Marta Kutas, Vicente J. Iragui-Madoz

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


We sought cognitive event-related potential (ERP) biomarkers of "Preclinical Alzheimer's disease" (Pre-AD) using an incidental verbal learning paradigm with high sensitivity to prodromal AD. Seven elderly persons, with normal cognition at the time of ERP recordings, but who showed subsequent cognitive decline or AD pathology at autopsy (n = 5, mean Braak stage = 2.8), were compared to 12 "robust" normal elderly (RNE) persons who remained cognitively normal (Mfollow-up= 9.0 years). EEG was recorded during a word repetition paradigm (semantically congruous (50%) and incongruous target words repeat ~10-140 seconds later). The RNE P600 congruous word repetition ERP effects (New minus Old congruous words) were significantly larger than in Pre-AD (mean amplitudes = 3.28 vs. 0.10 μV, p =.04). High group discrimination (84%) was achieved (by a P600 amplitude cutoff of ~1.5 μV). Abnormal P600 word repetition effects in cognitively normal elderly persons may be an important sign of synaptic dysfunction and Preclinical AD.

Original languageEnglish (US)
Pages (from-to)143-151
Number of pages9
JournalCognitive Neuroscience
Issue number3-4
StatePublished - Dec 2013


  • Alzheimer's disease
  • EEG
  • Event-related potentials
  • Memory
  • Mild cognitive impairment

ASJC Scopus subject areas

  • Cognitive Neuroscience


Dive into the research topics of 'Abnormal P600 word repetition effect in elderly persons with preclinical Alzheimer's disease'. Together they form a unique fingerprint.

Cite this