Increasing the number of irrelevant stimuli increases ability to detect countermeasures to the P300-based Complex Trial Protocol for concealed information detection

Xiaoqing Hu*, Daniel Hegeman, Elizabeth Landry, Joel P Rosenfeld

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


We previously found that simultaneously executing a mental countermeasure and an explicit required response impairs reaction time (RT)-based detection of countermeasure use in a P300- based concealed information test. To address this issue, we increased the numbers of irrelevant stimuli to eight, and manipulated the proportions of to-be-countered irrelevant stimuli from 25% to 50% to 75% in three groups. Results: Based on P300 data, 100% of the simple guilty (no countermeasure use) and 92% of the innocent subjects were correctly identified as having or not having concealed information. In the countermeasure groups, detection rates varied from 71% to 92% across the different groups. Notably, in the present study with eight irrelevant items, simultaneous countermeasure use was indicated by elevated RT in the 50% and 75% countermeasure proportion groups, which it was not, previously, with 50% (two) countermeasures and four irrelevants.

Original languageEnglish (US)
Pages (from-to)85-95
Number of pages11
Issue number1
StatePublished - Jan 1 2012


  • Complex trial protocol
  • Concealed information test
  • Countermeasures
  • Credibility assessment
  • Deception detection
  • P300

ASJC Scopus subject areas

  • Physiology
  • Neuropsychology and Physiological Psychology
  • Experimental and Cognitive Psychology
  • Physiology (medical)

Cite this