title: The Complex Trial Protocol (CTP): a new, countermeasure-resistant, accurate, P300-based method for detection of concealed information.
abstract: 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.
authors.affiliation: Department of Psychology, Northwestern University, Evanston, Illinois 60208, USA. jp-rosenfeld@northwestern.edu
authors.forename: J Peter
authors.initials: JP
authors.lastname: Rosenfeld
authors.forename: Elena
authors.initials: E
authors.lastname: Labkovsky
authors.forename: Michael
authors.initials: M
authors.lastname: Winograd
authors.forename: Ming A
authors.initials: MA
authors.lastname: Lui
authors.forename: Catherine
authors.initials: C
authors.lastname: Vandenboom
authors.forename: Erica
authors.initials: E
authors.lastname: Chedid
mesh_terms: D000293:Adolescent; D003627:Data Interpretation, Statistical; D004569:Electroencephalography / Q000379:methods*; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008014:Lie Detection / Q000523:psychology*; D008297:Male; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D055815:Young Adult