The Complex Trial Protocol (CTP): A new, countermeasure-resistant, accurate, P300-based method for detection of concealed information

J. Peter Rosenfeld, Elena Labkovsky, Michael Winograd, Ming A. Lui, Catherine Vandenboom, Erica Chedid

Research output: Contribution to journalArticlepeer-review

124 Scopus citations


A new P300-based concealed information test is described. A rare probe or frequent irrelevant stimulus appears in the same trial in which a target or nontarget later appears. One response follows the first stimulus and uses the same button press regardless of stimulus type. A later second stimulus then appears: target or nontarget. The subject presses one button for a target, another for a nontarget. A P300 to the first stimulus indicates probe recognition. One group was tested in 3 weeks for denied recognition of familiar information. Weeks 1 and 3 were guilty conditions; Week 2 was a countermeasure (CM) condition. The probe-irrelevant differences were significant in all weeks, and percent hits were >90%. Attempted CM use was detectable via elevated reaction time to the first stimulus. In a replication, results were similar. False positive rates for both studies varied from 0 to.08, yielding J. B. Grier (1971) A′ values from.9 to 1.0.

Original languageEnglish (US)
Pages (from-to)906-919
Number of pages14
Issue number6
StatePublished - Nov 1 2008


  • Concealed information tests
  • Credibility assessment
  • Event-related potentials
  • Guilty knowledge tests
  • Lie detection
  • P300
  • Psychophysiological detection of deception

ASJC Scopus subject areas

  • Neuroscience(all)
  • Neuropsychology and Physiological Psychology
  • Experimental and Cognitive Psychology
  • Neurology
  • Endocrine and Autonomic Systems
  • Developmental Neuroscience
  • Cognitive Neuroscience
  • Biological Psychiatry

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