Simple, effective countermeasures to P300-based tests of detection of concealed information

Psychophysiology. 2004 Mar;41(2):205-19. doi: 10.1111/j.1469-8986.2004.00158.x.

Abstract

We found countermeasures to protocols using P300 in concealed information tests. One, the "six-probe" protocol, in Experiment 1, uses six different crime details in one run. The countermeasure: generate covert responses to irrelevant stimuli for each probe category. Hit rates were 82% in the guilty group; 18% in the countermeasure group. The average reaction time (RT) distinguished these two groups, but with overlap in RT distributions. The "one-probe" protocol, in the second experiment, uses one crime detail as a probe. Here, one group was run in 3 weeks as a guilty group, a countermeasure group, and again as in Week 1. COUNTERMEASURE: Covert responses to irrelevant stimuli. In Week 1, hit rate was 92%. In Week 2, it was 50%. In Week 3, 58%. There was no overlap in the irrelevant RT distribution in Week 2: Countermeasure use was detectable. However, in Week 3, the RT distributions resembled those of Week 1; test-beaters could not be caught. These studies have shown that tests of deception detection based on P300 amplitude as a recognition index may be readily defeated with simple countermeasures that can be easily learned.

Publication types

  • Clinical Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Event-Related Potentials, P300 / physiology*
  • Female
  • Humans
  • Lie Detection*
  • Male
  • Mental Processes / physiology*
  • Motivation
  • Pilot Projects
  • Reaction Time / physiology